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3 Commits

Author SHA1 Message Date
Greg Johnston
2dd8b78336 v0.3.1 2023-06-14 09:56:41 -04:00
Greg Johnston
fd901d3e53 tests: fix broken SSR doctests (#1056) 2023-06-14 09:14:13 -04:00
Nova
d517f01e58 fix: replace ouroboros with self_cell (#1171) 2023-06-14 08:15:06 -04:00
731 changed files with 14807 additions and 47555 deletions

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@@ -1,39 +0,0 @@
---
name: Bug report
about: Create a report to help us improve
title: ''
labels: ''
assignees: ''
---
**Describe the bug**
A clear and concise description of what the bug is.
**Leptos Dependencies**
Please copy and paste the Leptos dependencies and features from your `Cargo.toml`.
For example:
```toml
leptos = { version = "0.3", features = ["serde"] }
leptos_axum = { version = "0.3", optional = true }
leptos_meta = { version = "0.3"}
leptos_router = { version = "0.3"}
```
**To Reproduce**
Steps to reproduce the behavior:
1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error
**Expected behavior**
A clear and concise description of what you expected to happen.
**Screenshots**
If applicable, add screenshots to help explain your problem.
**Additional context**
Add any other context about the problem here.

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@@ -1,7 +0,0 @@
contact_links:
- name: Support or Question
url: https://github.com/leptos-rs/leptos/discussions/new?category=q-a
about: Do you need help figuring out how to do something, or want some help troubleshooting a bug? You can ask in our Discussions section.
- name: Discord Discussions
url: https://discord.gg/YdRAhS7eQB
about: For more informal, real-time conversation and support, you can join our Discord server.

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@@ -1,20 +0,0 @@
---
name: Feature request
about: Suggest an idea for this project
title: ''
labels: ''
assignees: ''
---
**Is your feature request related to a problem? Please describe.**
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
**Describe the solution you'd like**
A clear and concise description of what you want to happen.
**Describe alternatives you've considered**
A clear and concise description of any alternative solutions or features you've considered.
**Additional context**
Add any other context or screenshots about the feature request here.

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@@ -1,29 +1,45 @@
name: Check Examples
name: Test
on:
push:
branches:
- main
branches: [main]
pull_request:
branches:
- main
branches: [main]
env:
CARGO_TERM_COLOR: always
jobs:
get-leptos-changed:
uses: ./.github/workflows/get-leptos-changed.yml
get-examples-matrix:
uses: ./.github/workflows/get-examples-matrix.yml
test:
name: Check
needs: [get-leptos-changed, get-examples-matrix]
if: needs.get-leptos-changed.outputs.leptos_changed == 'true'
name: Check examples ${{ matrix.os }} (using rustc ${{ matrix.rust }})
runs-on: ${{ matrix.os }}
strategy:
matrix: ${{ fromJSON(needs.get-examples-matrix.outputs.matrix) }}
fail-fast: false
uses: ./.github/workflows/run-cargo-make-task.yml
with:
directory: ${{ matrix.directory }}
cargo_make_task: "check"
toolchain: nightly
matrix:
rust:
- nightly
os:
- ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt
- name: Add wasm32-unknown-unknown
run: rustup target add wasm32-unknown-unknown
- name: Setup cargo-make
uses: davidB/rust-cargo-make@v1
- name: Cargo generate-lockfile
run: cargo generate-lockfile
- uses: Swatinem/rust-cache@v2
- name: Run cargo check on all examples
run: cargo make check-examples

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@@ -1,26 +1,45 @@
name: Check stable
name: Test
on:
push:
branches:
- main
branches: [main]
pull_request:
branches:
- main
branches: [main]
env:
CARGO_TERM_COLOR: always
jobs:
get-leptos-changed:
uses: ./.github/workflows/get-leptos-changed.yml
test:
name: Check
needs: [get-leptos-changed]
if: needs.get-leptos-changed.outputs.leptos_changed == 'true'
name: Check examples ${{ matrix.os }} (using rustc ${{ matrix.rust }})
runs-on: ${{ matrix.os }}
strategy:
matrix:
directory: [examples/counters_stable, examples/counter_without_macros]
uses: ./.github/workflows/run-cargo-make-task.yml
with:
directory: ${{ matrix.directory }}
cargo_make_task: "check"
toolchain: stable
rust:
- stable
os:
- ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt
- name: Add wasm32-unknown-unknown
run: rustup target add wasm32-unknown-unknown
- name: Setup cargo-make
uses: davidB/rust-cargo-make@v1
- name: Cargo generate-lockfile
run: cargo generate-lockfile
- uses: Swatinem/rust-cache@v2
- name: Run cargo check on all examples
run: cargo make --profile=github-actions check-stable

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.github/workflows/check.yml vendored Normal file
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@@ -0,0 +1,45 @@
name: Test
on:
push:
branches: [main]
pull_request:
branches: [main]
env:
CARGO_TERM_COLOR: always
jobs:
test:
name: Run `cargo check` ${{ matrix.os }} (using rustc ${{ matrix.rust }})
runs-on: ${{ matrix.os }}
strategy:
matrix:
rust:
- nightly
os:
- ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt
- name: Add wasm32-unknown-unknown
run: rustup target add wasm32-unknown-unknown
- name: Setup cargo-make
uses: davidB/rust-cargo-make@v1
- name: Cargo generate-lockfile
run: cargo generate-lockfile
- uses: Swatinem/rust-cache@v2
- name: Run cargo check on all libraries
run: cargo make --profile=github-actions check

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@@ -1,32 +0,0 @@
name: CI Changed Examples
on:
push:
branches:
- main
pull_request:
branches:
- main
jobs:
get-example-changed:
uses: ./.github/workflows/get-example-changed.yml
get-matrix:
needs: [get-example-changed]
uses: ./.github/workflows/get-changed-examples-matrix.yml
with:
example_changed: ${{ fromJSON(needs.get-example-changed.outputs.example_changed) }}
test:
name: CI
needs: [get-example-changed, get-matrix]
if: needs.get-example-changed.outputs.example_changed == 'true'
strategy:
matrix: ${{ fromJSON(needs.get-matrix.outputs.matrix) }}
fail-fast: false
uses: ./.github/workflows/run-cargo-make-task.yml
with:
directory: ${{ matrix.directory }}
cargo_make_task: "ci"
toolchain: nightly

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@@ -1,44 +0,0 @@
name: CI
on:
push:
branches:
- main
pull_request:
branches:
- main
jobs:
get-leptos-changed:
uses: ./.github/workflows/get-leptos-changed.yml
test:
name: CI
needs: [get-leptos-changed]
if: needs.get-leptos-changed.outputs.leptos_changed == 'true'
strategy:
matrix:
directory:
[
integrations/actix,
integrations/axum,
integrations/viz,
integrations/utils,
leptos,
leptos_config,
leptos_dom,
leptos_hot_reload,
leptos_macro,
leptos_reactive,
leptos_server,
meta,
router,
server_fn,
server_fn/server_fn_macro_default,
server_fn_macro,
]
uses: ./.github/workflows/run-cargo-make-task.yml
with:
directory: ${{ matrix.directory }}
cargo_make_task: "ci"
toolchain: nightly

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.github/workflows/fmt.yml vendored Normal file
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@@ -0,0 +1,34 @@
name: Test
on:
push:
branches: [main]
pull_request:
branches: [main]
env:
CARGO_TERM_COLOR: always
jobs:
test:
name: Run rustfmt
runs-on: ${{ matrix.os }}
strategy:
matrix:
rust:
- nightly
os:
- ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt
- name: Run Rustfmt
run: cargo fmt -- --check

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@@ -1,55 +0,0 @@
name: Changed Examples Matrix Call
on:
workflow_call:
inputs:
example_changed:
description: "Example Changed"
required: true
type: boolean
outputs:
matrix:
description: "Matrix"
value: ${{ jobs.get-example-changed.outputs.matrix }}
jobs:
get-example-changed:
name: Get Changed Example Matrix
runs-on: ubuntu-latest
outputs:
matrix: ${{ steps.set-matrix.outputs.matrix }}
steps:
- name: Checkout
uses: actions/checkout@v4
with:
fetch-depth: 0
- name: Get example project directories that changed
id: changed-dirs
uses: tj-actions/changed-files@v36
with:
dir_names: true
dir_names_max_depth: "2"
files: |
examples
!examples/cargo-make
!examples/gtk
!examples/hackernews_js_fetch
!examples/Makefile.toml
!examples/*.md
json: true
quotepath: false
- name: List example project directories that changed
run: echo '${{ steps.changed-dirs.outputs.all_changed_files }}'
- name: Set Matrix
id: set-matrix
run: |
if [ ${{ inputs.example_changed }} == 'true' ]; then
# Create matrix with changed directories
echo "matrix={\"directory\":${{ steps.changed-dirs.outputs.all_changed_files }}}" >> "$GITHUB_OUTPUT"
else
# Create matrix with one item to prevent an empty vector error
echo "matrix={\"directory\":[\"NO_CHANGE\"]}" >> "$GITHUB_OUTPUT"
fi

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@@ -1,39 +0,0 @@
name: Examples Changed Call
on:
workflow_call:
outputs:
example_changed:
description: "Example Changed"
value: ${{ jobs.get-example-changed.outputs.example_changed }}
jobs:
get-example-changed:
name: Get Example Changed
runs-on: ubuntu-latest
outputs:
example_changed: ${{ steps.set-example-changed.outputs.example_changed }}
steps:
- name: Checkout
uses: actions/checkout@v4
with:
fetch-depth: 0
- name: Get example files that changed
id: changed-files
uses: tj-actions/changed-files@v36
with:
files: |
examples
!examples/cargo-make
!examples/gtk
!examples/Makefile.toml
!examples/*.md
- name: List example files that changed
run: echo '${{ steps.changed-files.outputs.all_changed_files }}'
- name: Set example_changed
id: set-example-changed
run: |
echo "example_changed=${{ steps.changed-files.outputs.any_changed }}" >> "$GITHUB_OUTPUT"

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@@ -1,40 +0,0 @@
name: Get Examples Matrix Call
on:
workflow_call:
outputs:
matrix:
description: "Matrix"
value: ${{ jobs.create.outputs.matrix }}
jobs:
create:
name: Create Examples Matrix
runs-on: ubuntu-latest
outputs:
matrix: ${{ steps.set-matrix.outputs.matrix }}
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Install JQ Tool
uses: mbround18/install-jq@v1
- name: Set Matrix
id: set-matrix
run: |
examples=$(ls examples |
awk '{print "examples/" $0}' |
grep -v .md |
grep -v examples/Makefile.toml |
grep -v examples/cargo-make |
grep -v examples/gtk |
jq -R -s -c 'split("\n")[:-1]')
echo "Example Directories: $examples"
echo "matrix={\"directory\":$examples}" >> "$GITHUB_OUTPUT"
- name: Print Location Info
run: |
echo "Workspace: ${{ github.workspace }}"
pwd
ls | sort -u

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@@ -1,44 +0,0 @@
name: Get Leptos Changed Call
on:
workflow_call:
outputs:
leptos_changed:
description: "Leptos Changed"
value: ${{ jobs.create.outputs.leptos_changed }}
jobs:
create:
name: Detect Source Change
runs-on: ubuntu-latest
outputs:
leptos_changed: ${{ steps.set-source-changed.outputs.leptos_changed }}
steps:
- name: Checkout
uses: actions/checkout@v4
- name: Get source files that changed
id: changed-source
uses: tj-actions/changed-files@v36
with:
files: |
integrations
leptos
leptos_config
leptos_dom
leptos_hot_reload
leptos_macro
leptos_reactive
leptos_server
meta
router
server_fn
server_fn_macro
- name: List source files that changed
run: echo '${{ steps.changed-source.outputs.all_changed_files }}'
- name: Set leptos_changed
id: set-source-changed
run: |
echo "leptos_changed=${{ steps.changed-source.outputs.any_changed }}" >> "$GITHUB_OUTPUT"

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@@ -1,7 +1,7 @@
name: Deploy book
on:
push:
paths: ["docs/book/**"]
paths: ['docs/book/**']
branches:
- main
@@ -9,29 +9,29 @@ jobs:
deploy:
runs-on: ubuntu-latest
permissions:
contents: write # To push a branch
pull-requests: write # To create a PR from that branch
contents: write # To push a branch
pull-requests: write # To create a PR from that branch
steps:
- uses: actions/checkout@v4
with:
fetch-depth: 0
- name: Install mdbook
run: |
mkdir mdbook
curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.27/mdbook-v0.4.27-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
echo `pwd`/mdbook >> $GITHUB_PATH
- name: Deploy GitHub Pages
run: |
cd docs/book
mdbook build
git worktree add gh-pages
git config user.name "Deploy book from CI"
git config user.email ""
cd gh-pages
# Delete the ref to avoid keeping history.
git update-ref -d refs/heads/gh-pages
rm -rf *
mv ../book/* .
git add .
git commit -m "Deploy book $GITHUB_SHA to gh-pages"
git push --force --set-upstream origin gh-pages
- uses: actions/checkout@v3
with:
fetch-depth: 0
- name: Install mdbook
run: |
mkdir mdbook
curl -sSL https://github.com/rust-lang/mdBook/releases/download/v0.4.27/mdbook-v0.4.27-x86_64-unknown-linux-gnu.tar.gz | tar -xz --directory=./mdbook
echo `pwd`/mdbook >> $GITHUB_PATH
- name: Deploy GitHub Pages
run: |
cd docs/book
mdbook build
git worktree add gh-pages
git config user.name "Deploy book from CI"
git config user.email ""
cd gh-pages
# Delete the ref to avoid keeping history.
git update-ref -d refs/heads/gh-pages
rm -rf *
mv ../book/* .
git add .
git commit -m "Deploy book $GITHUB_SHA to gh-pages"
git push --force --set-upstream origin gh-pages

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@@ -1,114 +0,0 @@
name: Run Task
on:
workflow_call:
inputs:
directory:
required: true
type: string
cargo_make_task:
required: true
type: string
toolchain:
required: true
type: string
env:
CARGO_TERM_COLOR: always
CARGO_REGISTRIES_CRATES_IO_PROTOCOL: sparse
jobs:
test:
name: Run ${{ inputs.cargo_make_task }} (${{ inputs.toolchain }})
runs-on: ubuntu-latest
steps:
# Setup environment
- uses: actions/checkout@v4
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ inputs.toolchain }}
override: true
components: rustfmt
- name: Add wasm32-unknown-unknown
run: rustup target add wasm32-unknown-unknown
- name: Setup cargo-make
uses: davidB/rust-cargo-make@v1
- name: Cargo generate-lockfile
run: cargo generate-lockfile
- uses: Swatinem/rust-cache@v2
- name: Install Trunk
uses: jetli/trunk-action@v0.4.0
with:
version: "latest"
- name: Print Trunk Version
run: trunk --version
- name: Install Node.js
uses: actions/setup-node@v3
with:
node-version: 18
- uses: pnpm/action-setup@v2
name: Install pnpm
id: pnpm-install
with:
version: 8
run_install: false
- name: Get pnpm store directory
id: pnpm-cache
run: |
echo "STORE_PATH=$(pnpm store path)" >> $GITHUB_OUTPUT
- uses: actions/cache@v3
name: Setup pnpm cache
with:
path: ${{ steps.pnpm-cache.outputs.STORE_PATH }}
key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
restore-keys: |
${{ runner.os }}-pnpm-store-
- name: Maybe install chromedriver
run: |
project_makefile=${{inputs.directory}}/Makefile.toml
webdriver_count=$(cat $project_makefile | grep "cargo-make/webdriver.toml" | wc -l)
if [ $webdriver_count -eq 1 ]; then
if ! command -v chromedriver &>/dev/null; then
echo chromedriver required
sudo apt-get update
sudo apt-get install chromium-chromedriver
else
echo chromedriver is already installed
fi
else
echo chromedriver is not required
fi
- name: Maybe install playwright browser dependencies
run: |
for pw_path in $(find ${{inputs.directory}} -name playwright.config.ts)
do
pw_dir=$(dirname $pw_path)
if [ ! -v $pw_dir ]; then
echo "Playwright required in $pw_dir"
cd $pw_dir
pnpm dlx playwright install --with-deps
else
echo Playwright is not required
fi
done
# Run Cargo Make Task
- name: ${{ inputs.cargo_make_task }}
run: |
cd ${{ inputs.directory }}
cargo make --profile=github-actions ${{ inputs.cargo_make_task }}

45
.github/workflows/test.yml vendored Normal file
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@@ -0,0 +1,45 @@
name: Test
on:
push:
branches: [main]
pull_request:
branches: [main]
env:
CARGO_TERM_COLOR: always
jobs:
test:
name: Run tests ${{ matrix.os }} (using rustc ${{ matrix.rust }})
runs-on: ${{ matrix.os }}
strategy:
matrix:
rust:
- nightly
os:
- ubuntu-latest
steps:
- uses: actions/checkout@v3
- name: Setup Rust
uses: actions-rs/toolchain@v1
with:
toolchain: ${{ matrix.rust }}
override: true
components: rustfmt
- name: Add wasm32-unknown-unknown
run: rustup target add wasm32-unknown-unknown
- name: Setup cargo-make
uses: davidB/rust-cargo-make@v1
- name: Cargo generate-lockfile
run: cargo generate-lockfile
- uses: Swatinem/rust-cache@v2
- name: Run tests with all features
run: cargo make --profile=github-actions test

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@@ -1,26 +0,0 @@
name: CI Examples
on:
workflow_dispatch:
push:
tags:
- v*
schedule:
# Run once a day at 3:00 AM EST
- cron: "0 8 * * *"
jobs:
get-examples-matrix:
uses: ./.github/workflows/get-examples-matrix.yml
test:
name: CI
needs: [get-examples-matrix]
strategy:
matrix: ${{ fromJSON(needs.get-examples-matrix.outputs.matrix) }}
fail-fast: false
uses: ./.github/workflows/run-cargo-make-task.yml
with:
directory: ${{ matrix.directory }}
cargo_make_task: "ci"
toolchain: nightly

2
.gitignore vendored
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@@ -9,5 +9,3 @@ Cargo.lock
.idea
.direnv
.envrc
.vscode

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@@ -1,231 +0,0 @@
# Architecture
The goal of this document is to make it easier for contributors (and anyone
whos interested!) to understand the architecture of the framework.
The whole Leptos framework is built from a series of layers. Each of these layers
depends on the one below it, but each can be used independently from the ones
built on top of it. While running a command like `cargo leptos new --git
leptos-rs/start` pulls in the whole framework, its important to remember that
none of this is magic: each layer of that onion can be stripped away and
reimplemented, configured, or adapted as needed, incrementally.
> Everything that follows will assume you have a good working understanding
> of the framework. There will be explanations of how some parts of it work
> or fit together, but these are not docs. They assume you know what Im
> talking about.
## The Reactive System: `leptos_reactive`
The reactive system allows you to define dynamic values (signals),
the relationships between them (derived signals and memos), and the side effects
that run in response to them (effects).
These concepts are completely independent of the DOM and can be used to drive
any kind of reactive updates. The reactive system is based on the assumption
that data is relatively cheap, and side effects are relatively expensive. Its
goal is to minimize those side effects (like updating the DOM or making a network
requests) as infrequently as possible.
The reactive system is implemented as a single data structure that exists at
runtime. In exchange for giving ownership over a value to the reactive system
(by creating a signal), you receive a `Copy + 'static` identifier for its
location in the reactive system. This enables most of the ergonomics of storing
and sharing state, the use of callback closures without lifetime issues, etc.
This is implemented by storing signals in a slotmap arena. The signal, memo,
and scope types that are exposed to users simply carry around an index into that
slotmap.
> Items owned by the reactive system are dropped when the corresponding reactive
> scope is dropped, i.e., when the component or section of the UI theyre
> created in is removed. In a sense, Leptos implements a “garbage collector”
> in which the lifetime of data is tied to the lifetime of the UI, not Rusts
> lexical scopes.
## The DOM Renderer: `leptos_dom`
The reactive system can be used to drive any kinds of side effects. One very
common side effect is calling an imperative method, for example to update the
DOM.
The entire DOM renderer is built on top of the reactive system. It provides
a builder pattern that can be used to create DOM elements dynamically.
The renderer assumes, as a convention, that dynamic attributes, classes,
styles, and children are defined by being passed a `Fn() -> T`, where their
static equivalents just receive `T`. Theres nothing about this that is
divinely ordained, but its a useful convention because it allows us to use
zero-overhead derived signals as one of several ways to indicate dynamic
content.
`leptos_dom` also contains code for server-side rendering of the same
UI views to HTML, either for out-of-order streaming (`src/ssr.rs`) or
in-order streaming/async rendering (`src/ssr_in_order.rs`).
## The Macros: `leptos_macro`
Its entirely possible to write Leptos code with no macros at all. The
`view` and `component` macros, the most common, can be replaced by
the builder syntax and simple functions (see the `counter_without_macros`
example). But the macros enable a JSX-like syntax for describing views.
This package also contains the `Params` derive macro used for typed
queries and route params in the router.
### Macro-based Optimizations
Leptos 0.0.x was built much more heavily on macros. Taking its cues
from SolidJS, the `view` macro emitted different code for CSR, SSR, and
hydration, optimizing each. The CSR/hydrate versions worked by compiling
the view to an HTML template string, cloning that `<template>`, and
traversing the DOM to set up reactivity. The SSR version worked similarly
by compiling the static parts of the view to strings at compile time,
reducing the amount of work that needed to be done on each request.
Proc macros are hard, and this system was brittle. 0.1 introduced a
more robust renderer, including the builder syntax, and rebuilt the `view`
macro to use that builder syntax instead. It moved the optimized-but-buggy
CSR version of the macro to a more-limited `template` macro.
The `view` macro now separately optimizes SSR to use the same static-string
optimizations, which (by our benchmarks) makes Leptos about 3-4x faster
than similar Rust frontend frameworks in its HTML rendering.
> The optimization is pretty straightforward. Consider the following view:
>
> ```rust
> view! { cx,
> <main class="text-center">
> <div class="flex-col">
> <button>"Click me."</button>
> <p class="italic">"Text."</p>
> </div>
> </main>
> }
> ```
>
> Internally, with the builder this is something like
>
> ```rust
> Element {
> tag: "main",
> attrs: vec![("class", "text-center")],
> children: vec![
> Element {
> tag: "div",
> attrs: vec![("class", "flex-col")],
> children: vec![
> Element {
> tag: "button",
> attrs: vec![],
> children: vec!["Click me"]
> },
> Element {
> tag: "p",
> attrs: vec![("class", "italic")],
> children: vec!["Text"]
> }
> ]
> }
> ]
> }
> ```
>
> This is a _bunch_ of small allocations and separate strings,
> and in early 0.1 versions we used a `SmallVec` for children and
> attributes and actually caused some stack overflows.
>
> But if you look at the view itself you can see that none of this
> will _ever_ change. So we can actually optimize it at compile
> time to a single `&'static str`:
>
> ```rust
> r#"<main class="text-center">
> <div class="flex-col">
> <button>"Click me."</button>
> <p class="italic">"Text."</p>
> </div>
> </main>"#
> ```
## Server Functions (`leptos_server`, `server_fn`, and `server_fn_macro`)
Server functions are a framework-agnostic shorthand for converting
a function, whose body can only be run on the server, into an ad hoc
REST API endpoint, and then generating code on the client to call that
endpoint when you call the function.
These are inspired by Solid/Blings `server$` functions, and theres
similar work being done in a number of other JavaScript frameworks.
RPC is not a new idea, but these kinds of server functions may be.
Specifically, by using web standards (defaulting to `POST`/`GET` requests
with URL-encoded form data) they allow easy graceful degradation and the
use of the `<form>` element.
This function is split across three packages so that `server_fn` and
`server_fn_macro` can be used by other frameworks. `leptos_server`
includes some Leptos-specific reactive functionality (like actions).
## `leptos`
This package is built on and reexports most of the layers already
mentioned, and implements a number of control-flow components (`<Show/>`,
`<ErrorBoundary/>`, `<For/>`, `<Suspense/>`, `<Transition/>`) that use
public APIs of the other packages.
This is the main entrypoint for users, but is relatively light itself.
## `leptos_meta`
This package exists to allow you to work with tags normally found in
the `<head>`, from within your components.
It is implemented as a distinct package, rather than part of
`leptos_dom`, on the principle that “what can be implemented in userland,
should be.” The framework can be used without it, so its not in core.
## `leptos_router`
The router originates as a direct port of `solid-router`, which is the
origin of most of its terminology, architecture, and route-matching logic.
Subsequent developments (like animated routing, and managing route transitions
given the lack of `useTransition` in Leptos) have caused it to diverge
slightly from Solids exact code, but it is still very closely related.
The core principle here is “nested routing,” dividing a single page
into independently-rendered parts. This is described in some detail in the docs.
Like `leptos_meta`, it is implemented as a distinct package, because it
can be replaced with another router or with none. The framework can be used
without it, so its not in core.
## Server Integrations
The server integrations are the most “frameworky” layer of the whole framework.
These **do** assume the use of `leptos`, `leptos_router`, and `leptos_meta`.
They specifically draw routing data from `leptos_router`, and inject the
metadata from `leptos_meta` into the `<head>` appropriately.
But of course, if you one day create `leptos-helmet` and `leptos-better-router`,
you can create new server integrations that plug them into the SSR rendering
methods from `leptos_dom` instead. Everything involved is quite modular.
These packages essentially provide helpers that save the templates and user apps
from including a huge amount of boilerplate to connect the various other packages
correctly. Again, early versions of the framework examples are illustrative here
for reference: they include large amounts of manual SSR route handling, etc.
## `cargo-leptos` helpers
`leptos_config` and `leptos_hot_reload` exist to support two different features
of `cargo-leptos`, namely its configuration and its view-patching/hot-reloading
features.
Its important to say that the main feature `cargo-leptos` remains its ability
to conveniently tie together different build tooling, compiling your app to
WASM for the browser, building the server version, pulling in SASS and
Tailwind, etc. It is an extremely good build tool, not a magic formula. Each
of the examples includes instructions for how to run the examples without
`cargo-leptos`.

View File

@@ -2,7 +2,7 @@
_This Code of Conduct is based on the [Rust Code of Conduct](https://www.rust-lang.org/policies/code-of-conduct)
and the [Bevy Code of Conduct](https://raw.githubusercontent.com/bevyengine/bevy/main/CODE_OF_CONDUCT.md),
which are adapted from the [Node.js Policy on Trolling](http://blog.izs.me/post/30036893703/policy-on-trolling)
which are adapted from the [Node.js Policy on Trolling](http://blog.izs.me/post/30036893703/policy-on-trolling)
and the [Contributor Covenant](https://www.contributor-covenant.org)._
## Our Pledge

View File

@@ -1,94 +0,0 @@
# Contributing to Leptos
Thanks for your interesting in contributing to Leptos! This is a truly
community-driven framework, and while we have a central maintainer (@gbj)
large parts of the renderer, reactive system, and server integrations have
all been written by other contributors. Contributions are always welcome.
Participation in this community is governed by a [Code of Conduct](./CODE_OF_CONDUCT.md).
Some of the most active conversations around development take place on our
[Discord server](https://discord.gg/YdRAhS7eQB).
This guide seeks to
- describe some of the frameworks values (in a technical, not an ethical, sense)
- provide a high-level overview of how the pieces of the framework fit together
- orient you to the organization of this repository
## Values
Leptos, as a framework, reflects certain technical values:
- **Expose primitives rather than imposing patterns.** Provide building blocks
that users can combine together to build up more complex behavior, rather than
requiring users follow certain templates, file formats, etc. e.g., components
are defined as functions, rather than a bespoke single-file component format.
The reactive system feeds into the rendering system, rather than being defined
by it.
- **Bottom-up over top-down.** If you envision a users application as a tree
(like an HTML document), push meaning toward the leaves of the tree. e.g., If data
needs to be loaded, load it in a granular primitive (resources) rather than a
route- or page-level data structure.
- **Performance by default.** When possible, users should only pay for what they
use. e.g., we dont make all component props reactive by default. This is
because doing so would force the overhead of a reactive prop onto props that dont
need to be reactive.
- **Full-stack performance.** Performance cant be limited to a single metric,
whether thats a DOM rendering benchmark, WASM binary size, or server response
time. Use methods like HTTP streaming and progressive enhancement to enable
applications to load, become interactive, and respond as quickly as possible.
- **Use safe Rust.** Theres no need for `unsafe` Rust in the framework, and
avoiding it at all costs reduces the maintenance and testing burden significantly.
- **Embrace Rust semantics.** Especially in things like UI templating, use Rust
semantics or extend them in a predictable way with control-flow components
rather than overloading the meaning of Rust terms like `if` or `for` in a
framework-specific way.
- **Enhance ergonomics without obfuscating whats happening.** This is by far
the hardest to achieve. Its often the case that adding additional layers to
improve DX (like a custom build tool and starter templates) comes across as
“too magic” to some people who havent had to build the same things manually.
When possible, make it easier to see how the pieces fit together, without
sacrificing the improved DX.
## Processes
We do not have PR templates or formal processes for approving PRs. But there
are a few guidelines that will make it a better experience for everyone:
- Run `cargo fmt` before submitting your code.
- Keep PRs limited to addressing one feature or one issue, in general. In some
cases (e.g., “reduce allocations in the reactive system”) this may touch a number
of different areas, but is still conceptually one thing.
- If its an unsolicited PR not linked to an open issue, please include a
specific explanation for what its trying to achieve. For example: “When I
was trying to deploy my app under _circumstances X_, I found that the way
_function Z_ was implemented caused _issue Z_. This PR should fix that by
_solution._
- Our CI tests every PR against all the existing examples, sometimes requiring
compilation for both server and client side, etc. Its thorough but slow. If
you want to run CI locally to reduce frustration, you can do that by installing
`cargo-make` and using `cargo make check && cargo make test && cargo make
check-examples`.
## Before Submitting a PR
We have a fairly extensive CI setup that runs both lints (like `rustfmt` and `clippy`)
and tests on PRs. You can run most of these locally if you have `cargo-make` installed.
If you added an example, make sure to add it to the list in `examples/Makefile.toml`.
From the root directory of the repo, run
- `cargo +nightly fmt`
- `cargo +nightly make check`
- `cargo +nightly make test`
- `cargo +nightly make check-examples`
- `cargo +nightly make --profile=github-actions ci`
If you modified an example:
- `cd examples/your_example`
- `cargo +nightly fmt -- --config-path ../..`
- `cargo +nightly make --profile=github-actions verify-flow`
## Architecture
See [ARCHITECTURE.md](./ARCHITECTURE.md).

View File

@@ -1,5 +1,4 @@
[workspace]
resolver = "2"
members = [
# core
"leptos",
@@ -26,22 +25,22 @@ members = [
exclude = ["benchmarks", "examples"]
[workspace.package]
version = "0.5.1"
version = "0.3.1"
[workspace.dependencies]
leptos = { path = "./leptos", version = "0.5.1" }
leptos_dom = { path = "./leptos_dom", version = "0.5.1" }
leptos_hot_reload = { path = "./leptos_hot_reload", version = "0.5.1" }
leptos_macro = { path = "./leptos_macro", version = "0.5.1" }
leptos_reactive = { path = "./leptos_reactive", version = "0.5.1" }
leptos_server = { path = "./leptos_server", version = "0.5.1" }
server_fn = { path = "./server_fn", version = "0.5.1" }
server_fn_macro = { path = "./server_fn_macro", version = "0.5.1" }
server_fn_macro_default = { path = "./server_fn/server_fn_macro_default", version = "0.5.1" }
leptos_config = { path = "./leptos_config", version = "0.5.1" }
leptos_router = { path = "./router", version = "0.5.1" }
leptos_meta = { path = "./meta", version = "0.5.1" }
leptos_integration_utils = { path = "./integrations/utils", version = "0.5.1" }
leptos = { path = "./leptos", default-features = false, version = "0.3.1" }
leptos_dom = { path = "./leptos_dom", default-features = false, version = "0.3.1" }
leptos_hot_reload = { path = "./leptos_hot_reload", version = "0.3.1" }
leptos_macro = { path = "./leptos_macro", default-features = false, version = "0.3.1" }
leptos_reactive = { path = "./leptos_reactive", default-features = false, version = "0.3.1" }
leptos_server = { path = "./leptos_server", default-features = false, version = "0.3.1" }
server_fn = { path = "./server_fn", default-features = false, version = "0.3.1" }
server_fn_macro = { path = "./server_fn_macro", default-features = false, version = "0.3.1" }
server_fn_macro_default = { path = "./server_fn/server_fn_macro_default", default-features = false, version = "0.3.1" }
leptos_config = { path = "./leptos_config", default-features = false, version = "0.3.1" }
leptos_router = { path = "./router", version = "0.3.1" }
leptos_meta = { path = "./meta", default-features = false, version = "0.3.1" }
leptos_integration_utils = { path = "./integrations/utils", version = "0.3.1" }
[profile.release]
codegen-units = 1

View File

@@ -3,37 +3,118 @@
# cargo install --force cargo-make
############
[env]
CARGO_MAKE_EXTEND_WORKSPACE_MAKEFILE = true
[config]
# make tasks run at the workspace root
default_to_workspace = false
[tasks.check]
clear = true
dependencies = [
"check-all",
"check-wasm",
"check-all-release",
"check-wasm-release",
]
[tasks.check-all]
command = "cargo"
args = ["+nightly", "check-all-features"]
install_crate = "cargo-all-features"
[tasks.check-wasm]
clear = true
dependencies = [{ name = "check-wasm", path = "leptos" }]
[tasks.check-all-release]
command = "cargo"
args = ["+nightly", "check-all-features"]
install_crate = "cargo-all-features"
[tasks.check-wasm-release]
clear = true
dependencies = [{ name = "check-wasm-release", path = "leptos" }]
[tasks.check-examples]
clear = true
dependencies = [
{ name = "check", path = "examples/counter" },
{ name = "check", path = "examples/counter_isomorphic" },
{ name = "check", path = "examples/counters" },
{ name = "check", path = "examples/error_boundary" },
{ name = "check", path = "examples/errors_axum" },
{ name = "check", path = "examples/fetch" },
{ name = "check", path = "examples/hackernews" },
{ name = "check", path = "examples/hackernews_axum" },
{ name = "check", path = "examples/login_with_token_csr_only" },
{ name = "check", path = "examples/parent_child" },
{ name = "check", path = "examples/router" },
{ name = "check", path = "examples/session_auth_axum" },
{ name = "check", path = "examples/slots" },
{ name = "check", path = "examples/ssr_modes" },
{ name = "check", path = "examples/ssr_modes_axum" },
{ name = "check", path = "examples/tailwind" },
{ name = "check", path = "examples/tailwind_csr_trunk" },
{ name = "check", path = "examples/todo_app_sqlite" },
{ name = "check", path = "examples/todo_app_sqlite_axum" },
{ name = "check", path = "examples/todo_app_sqlite_viz" },
{ name = "check", path = "examples/todomvc" },
]
[tasks.check-stable]
workspace = false
clear = true
dependencies = [
{ name = "check", path = "examples/counter_without_macros" },
{ name = "check", path = "examples/counters_stable" },
]
[tasks.ci-examples]
workspace = false
cwd = "examples"
command = "cargo"
args = ["make", "ci-clean"]
[tasks.test]
clear = true
dependencies = [
"test-all",
"test-leptos_macro-example",
"doc-leptos_macro-example",
]
[tasks.check-examples]
workspace = false
cwd = "examples"
[tasks.test-all]
command = "cargo"
args = ["make", "check-clean"]
args = ["+nightly", "test-all-features"]
install_crate = "cargo-all-features"
[tasks.build-examples]
workspace = false
[tasks.test-leptos_macro-example]
description = "Tests the leptos_macro/example to check if macro handles doc comments correctly"
command = "cargo"
args = ["+nightly", "test", "--doc"]
cwd = "leptos_macro/example"
install_crate = false
[tasks.doc-leptos_macro-example]
description = "Docs the leptos_macro/example to check if macro handles doc comments correctly"
command = "cargo"
args = ["+nightly", "doc"]
cwd = "leptos_macro/example"
install_crate = false
[tasks.test-examples]
description = "Run all unit and web tests for examples"
cwd = "examples"
command = "cargo"
args = ["make", "build-clean"]
args = ["make", "test-unit-and-web"]
[tasks.verify-examples]
description = "Run all quality checks and tests for examples"
cwd = "examples"
command = "cargo"
args = ["make", "verify-flow"]
[tasks.clean-examples]
workspace = false
description = "Clean all example projects"
cwd = "examples"
command = "cargo"
args = ["make", "clean"]
args = ["make", "clean-all"]
[env]
RUSTFLAGS = ""
LEPTOS_OUTPUT_NAME = "ci" # allows examples to check/build without cargo-leptos
[env.github-actions]
RUSTFLAGS = "-D warnings"

View File

@@ -8,19 +8,15 @@
[![Discord](https://img.shields.io/discord/1031524867910148188?color=%237289DA&label=discord)](https://discord.gg/YdRAhS7eQB)
[![Matrix](https://img.shields.io/badge/Matrix-leptos-grey?logo=matrix&labelColor=white&logoColor=black)](https://matrix.to/#/#leptos:matrix.org)
[Website](https://leptos.dev) | [Book](https://leptos-rs.github.io/leptos/) | [Docs.rs](https://docs.rs/leptos/latest/leptos/) | [Playground](https://codesandbox.io/p/sandbox/leptos-rtfggt?file=%2Fsrc%2Fmain.rs%3A1%2C1) | [Discord](https://discord.gg/YdRAhS7eQB)
You can find a list of useful libraries and example projects at [`awesome-leptos`](https://github.com/leptos-rs/awesome-leptos).
# Leptos
```rust
use leptos::*;
#[component]
pub fn SimpleCounter(initial_value: i32) -> impl IntoView {
pub fn SimpleCounter(cx: Scope, initial_value: i32) -> impl IntoView {
// create a reactive signal with the initial value
let (value, set_value) = create_signal(initial_value);
let (value, set_value) = create_signal(cx, initial_value);
// create event handlers for our buttons
// note that `value` and `set_value` are `Copy`, so it's super easy to move them into closures
@@ -29,29 +25,23 @@ pub fn SimpleCounter(initial_value: i32) -> impl IntoView {
let increment = move |_| set_value.update(|value| *value += 1);
// create user interfaces with the declarative `view!` macro
view! {
view! { cx,
<div>
<button on:click=clear>Clear</button>
<button on:click=decrement>-1</button>
// text nodes can be quoted or unquoted
<button on:click=clear>"Clear"</button>
<button on:click=decrement>"-1"</button>
<span>"Value: " {value} "!"</span>
<button on:click=increment>+1</button>
<button on:click=increment>"+1"</button>
</div>
}
}
// Easy to use with Trunk (trunkrs.dev) or with a simple wasm-bindgen setup
pub fn main() {
mount_to_body(|| view! {
<SimpleCounter initial_value=3 />
})
mount_to_body(|cx| view! { cx, <SimpleCounter initial_value=3 /> })
}
```
### Important Note
This example, and the entire `main` branch, now reflect the upcoming `0.5.1` release. You can use `0.5.1` with the `0.5.1-beta` release on crates.io or by a git dependency on the `main` branch of this repo. [Click here for the 0.4.9 `README`](https://crates.io/crates/leptos).
## About the Framework
Leptos is a full-stack, isomorphic Rust web framework leveraging fine-grained reactivity to build declarative user interfaces.
@@ -76,7 +66,7 @@ Here are some resources for learning more about Leptos:
## `nightly` Note
Most of the examples assume youre using `nightly` version of Rust and the `nightly` feature of Leptos. To use `nightly` Rust, you can either set your toolchain globally or on per-project basis.
Most of the examples assume youre using `nightly` version of Rust. For this, you can either set your toolchain globally or on per-project basis.
To set `nightly` as a default toolchain for all projects (and add the ability to compile Rust to WebAssembly, if you havent already):
@@ -94,7 +84,13 @@ channel = "nightly"
targets = ["wasm32-unknown-unknown"]
```
The `nightly` feature enables the function call syntax for accessing and setting signals, as opposed to `.get()` and `.set()`. This leads to a consistent mental model in which accessing a reactive value of any kind (a signal, memo, or derived signal) is always represented as a function call. This is only possible with nightly Rust and the `nightly` feature.
If youre on `stable`, note the following:
1. You need to enable the `"stable"` flag in `Cargo.toml`: `leptos = { version = "0.2", features = ["stable"] }`
2. `nightly` enables the function call syntax for accessing and setting signals. If youre using `stable`,
youll just call `.get()`, `.set()`, or `.update()` manually. Check out the
[`counters_stable` example](https://github.com/leptos-rs/leptos/blob/main/examples/counters_stable/src/main.rs)
for examples of the correct API.
## `cargo-leptos`
@@ -113,7 +109,7 @@ Open browser to [http://localhost:3000/](http://localhost:3000/).
### Whats up with the name?
_Leptos_ (λεπτός) is an ancient Greek word meaning “thin, light, refined, fine-grained.” To me, a classicist and not a dog owner, it evokes the lightweight reactive system that powers the framework. I've since learned the same word is at the root of the medical term “leptospirosis,” a blood infection that affects humans and animals... My bad. No dogs were harmed in the creation of this framework.
_Leptos_ (λεπτός) is an ancient Greek word meaning “thin, light, refine, fine-grained.” To me, a classicist and not a dog owner, it evokes the lightweight reactive system that powers the framework. I've since learned the same word is at the root of the medical term “leptospirosis,” a blood infection that affects humans and animals... My bad. No dogs were harmed in the creation of this framework.
### Is it production ready?
@@ -121,7 +117,7 @@ People usually mean one of three things by this question.
1. **Are the APIs stable?** i.e., will I have to rewrite my whole app from Leptos 0.1 to 0.2 to 0.3 to 0.4, or can I write it now and benefit from new features and updates as new versions come?
The APIs are basically settled. Were adding new features, but were very happy with where the type system and patterns have landed. I would not expect major breaking changes to your code to adapt to future releases, in terms of architecture.
The APIs are basically settled. Were adding new features, but were very happy with where the type system and patterns have landed. I would not expect major breaking changes to your code to adapt to future releases. The sorts of breaking changes that we discuss are things like “Oh yeah, that function should probably take `cx` as its argument...” not major changes to the way you write your application.
2. **Are there bugs?**
@@ -160,13 +156,13 @@ There are some practical differences that make a significant difference:
- **Templating:** Leptos uses a JSX-like template format (built on [syn-rsx](https://github.com/stoically/syn-rsx)) for its `view` macro. Sycamore offers the choice of its own templating DSL or a builder syntax.
- **Server integration:** Leptos provides primitives that encourage HTML streaming and allow for easy async integration and RPC calls, even without WASM enabled, making it easy to opt into integrations between your frontend and backend code without pushing you toward any particular metaframework patterns.
- **Read-write segregation:** Leptos, like Solid, encourages read-write segregation between signal getters and setters, so you end up accessing signals with tuples like `let (count, set_count) = create_signal(0);` _(If you prefer or if it's more convenient for your API, you can use [`create_rw_signal`](https://docs.rs/leptos/latest/leptos/fn.create_rw_signal.html) to give a unified read/write signal.)_
- **Read-write segregation:** Leptos, like Solid, encourages read-write segregation between signal getters and setters, so you end up accessing signals with tuples like `let (count, set_count) = create_signal(cx, 0);` _(If you prefer or if it's more convenient for your API, you can use [`create_rw_signal`](https://docs.rs/leptos/latest/leptos/fn.create_rw_signal.html) to give a unified read/write signal.)_
- **Signals are functions:** In Leptos, you can call a signal to access it rather than calling a specific method (so, `count()` instead of `count.get()`) This creates a more consistent mental model: accessing a reactive value is always a matter of calling a function. For example:
```rust
let (count, set_count) = create_signal(0); // a signal
let (count, set_count) = create_signal(cx, 0); // a signal
let double_count = move || count() * 2; // a derived signal
let memoized_count = create_memo(move |_| count() * 3); // a memo
let memoized_count = create_memo(cx, move |_| count() * 3); // a memo
// all are accessed by calling them
assert_eq!(count(), 0);
assert_eq!(double_count(), 0);

View File

@@ -1,13 +0,0 @@
# Security Policy
## Reporting a Vulnerability
To report a suspected security issue, please contact security@leptos.dev rather than opening
a public issue.
## Supported Versions
The most-recently-released version of the library is supported with security updates.
For example, if a security issue is discovered that affects 0.3.2 and all later releases,
a 0.4.x patch will be released but a new 0.3.x patch release will not be made. You should
plan to update to the latest version to receive any new features or bugfixes of any kind.

View File

@@ -4,16 +4,10 @@ version = "0.1.0"
edition = "2021"
[dependencies]
l0410 = { package = "leptos", version = "0.4.10", features = [
"nightly",
"ssr",
] }
leptos = { path = "../leptos", features = ["ssr", "nightly"] }
leptos_reactive = { path = "../leptos_reactive", features = ["ssr", "nightly"] }
tachydom = { git = "https://github.com/gbj/tachys", features = ["nightly"] }
tachy_maccy = { git = "https://github.com/gbj/tachys", features = ["nightly"] }
l021 = { package = "leptos", version = "0.2.1" }
leptos = { path = "../leptos", default-features = false, features = ["ssr"] }
sycamore = { version = "0.8", features = ["ssr"] }
yew = { version = "0.20", features = ["ssr"] }
yew = { git = "https://github.com/yewstack/yew", features = ["ssr"] }
tokio-test = "0.4"
miniserde = "0.1"
gloo = "0.8"
@@ -26,6 +20,7 @@ strum_macros = "0.24"
serde = { version = "1", features = ["derive", "rc"] }
serde_json = "1"
tera = "1"
reactive-signals = "0.1.0-alpha.4"
[dependencies.web-sys]
version = "0.3"

View File

@@ -2,6 +2,6 @@
extern crate test;
mod reactive;
mod ssr;
//åmod reactive;
//mod ssr;
mod todomvc;

View File

@@ -6,122 +6,13 @@ fn leptos_deep_creation(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let signal = create_rw_signal(0);
let mut memos = Vec::<Memo<usize>>::new();
for _ in 0..1000usize {
let prev = memos.last().copied();
if let Some(prev) = prev {
memos.push(create_memo(move |_| prev.get() + 1));
} else {
memos.push(create_memo(move |_| signal.get() + 1));
}
}
});
runtime.dispose();
}
#[bench]
fn leptos_deep_update(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let signal = create_rw_signal(0);
let mut memos = Vec::<Memo<usize>>::new();
for _ in 0..1000usize {
if let Some(prev) = memos.last().copied() {
memos.push(create_memo(move |_| prev.get() + 1));
} else {
memos.push(create_memo(move |_| signal.get() + 1));
}
}
signal.set(1);
assert_eq!(memos[999].get(), 1001);
});
runtime.dispose();
}
#[bench]
fn leptos_narrowing_down(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let sigs = (0..1000).map(|n| create_signal(n)).collect::<Vec<_>>();
let reads = sigs.iter().map(|(r, _)| *r).collect::<Vec<_>>();
let writes = sigs.iter().map(|(_, w)| *w).collect::<Vec<_>>();
let memo =
create_memo(move |_| reads.iter().map(|r| r.get()).sum::<i32>());
assert_eq!(memo(), 499500);
});
runtime.dispose();
}
#[bench]
fn leptos_fanning_out(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let sig = create_rw_signal(0);
let memos = (0..1000)
.map(|_| create_memo(move |_| sig.get()))
.collect::<Vec<_>>();
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 0);
sig.set(1);
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 1000);
});
runtime.dispose();
}
#[bench]
fn leptos_narrowing_update(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let acc = Rc::new(Cell::new(0));
let sigs = (0..1000).map(|n| create_signal(n)).collect::<Vec<_>>();
let reads = sigs.iter().map(|(r, _)| *r).collect::<Vec<_>>();
let writes = sigs.iter().map(|(_, w)| *w).collect::<Vec<_>>();
let memo =
create_memo(move |_| reads.iter().map(|r| r.get()).sum::<i32>());
assert_eq!(memo(), 499500);
create_isomorphic_effect({
let acc = Rc::clone(&acc);
move |_| {
acc.set(memo());
}
});
assert_eq!(acc.get(), 499500);
writes[1].update(|n| *n += 1);
writes[10].update(|n| *n += 1);
writes[100].update(|n| *n += 1);
assert_eq!(acc.get(), 499503);
assert_eq!(memo(), 499503);
});
runtime.dispose();
}
#[bench]
fn l0410_deep_creation(b: &mut Bencher) {
use l0410::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let signal = create_rw_signal(cx, 0);
let mut memos = Vec::<Memo<usize>>::new();
for _ in 0..1000usize {
if let Some(prev) = memos.last().copied() {
let prev = memos.last().copied();
if let Some(prev) = prev {
memos.push(create_memo(cx, move |_| prev.get() + 1));
} else {
memos.push(create_memo(cx, move |_| signal.get() + 1));
@@ -135,8 +26,8 @@ fn l0410_deep_creation(b: &mut Bencher) {
}
#[bench]
fn l0410_deep_update(b: &mut Bencher) {
use l0410::*;
fn leptos_deep_update(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
@@ -160,8 +51,238 @@ fn l0410_deep_update(b: &mut Bencher) {
}
#[bench]
fn l0410_narrowing_down(b: &mut Bencher) {
use l0410::*;
fn leptos_narrowing_down(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let sigs =
(0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>();
let reads = sigs.iter().map(|(r, _)| *r).collect::<Vec<_>>();
let writes = sigs.iter().map(|(_, w)| *w).collect::<Vec<_>>();
let memo = create_memo(cx, move |_| {
reads.iter().map(|r| r.get()).sum::<i32>()
});
assert_eq!(memo(), 499500);
})
.dispose()
});
runtime.dispose();
}
#[bench]
fn leptos_fanning_out(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let sig = create_rw_signal(cx, 0);
let memos = (0..1000)
.map(|_| create_memo(cx, move |_| sig.get()))
.collect::<Vec<_>>();
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 0);
sig.set(1);
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 1000);
})
.dispose()
});
runtime.dispose();
}
#[bench]
fn leptos_narrowing_update(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let acc = Rc::new(Cell::new(0));
let sigs =
(0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>();
let reads = sigs.iter().map(|(r, _)| *r).collect::<Vec<_>>();
let writes = sigs.iter().map(|(_, w)| *w).collect::<Vec<_>>();
let memo = create_memo(cx, move |_| {
reads.iter().map(|r| r.get()).sum::<i32>()
});
assert_eq!(memo(), 499500);
create_isomorphic_effect(cx, {
let acc = Rc::clone(&acc);
move |_| {
acc.set(memo());
}
});
assert_eq!(acc.get(), 499500);
writes[1].update(|n| *n += 1);
writes[10].update(|n| *n += 1);
writes[100].update(|n| *n += 1);
assert_eq!(acc.get(), 499503);
assert_eq!(memo(), 499503);
})
.dispose()
});
runtime.dispose();
}
#[bench]
fn leptos_scope_creation_and_disposal(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
let acc = Rc::new(Cell::new(0));
let disposers = (0..1000)
.map(|_| {
create_scope(runtime, {
let acc = Rc::clone(&acc);
move |cx| {
let (r, w) = create_signal(cx, 0);
create_isomorphic_effect(cx, {
move |_| {
acc.set(r());
}
});
w.update(|n| *n += 1);
}
})
})
.collect::<Vec<_>>();
for disposer in disposers {
disposer.dispose();
}
});
runtime.dispose();
}
#[bench]
fn rs_deep_update(b: &mut Bencher) {
use reactive_signals::{Scope, Signal, signal, runtimes::ClientRuntime, types::Func};
let sc = ClientRuntime::new_root_scope();
b.iter(|| {
let signal = signal!(sc, 0);
let mut memos = Vec::<Signal<Func<i32>, ClientRuntime>>::new();
for i in 0..1000usize {
let prev = memos.get(i.saturating_sub(1)).copied();
if let Some(prev) = prev {
memos.push(signal!(sc, move || prev.get() + 1))
} else {
memos.push(signal!(sc, move || signal.get() + 1))
}
}
signal.set(1);
assert_eq!(memos[999].get(), 1001);
});
}
#[bench]
fn rs_fanning_out(b: &mut Bencher) {
use reactive_signals::{Scope, Signal, signal, runtimes::ClientRuntime, types::Func};
let cx = ClientRuntime::new_root_scope();
b.iter(|| {
let sig = signal!(cx, 0);
let memos = (0..1000)
.map(|_| signal!(cx, move || sig.get()))
.collect::<Vec<_>>();
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 0);
sig.set(1);
assert_eq!(memos.iter().map(|m| m.get()).sum::<i32>(), 1000);
});
}
#[bench]
fn rs_narrowing_update(b: &mut Bencher) {
use reactive_signals::{Scope, Signal, signal, runtimes::ClientRuntime, types::Func};
let cx = ClientRuntime::new_root_scope();
b.iter(|| {
let acc = Rc::new(Cell::new(0));
let sigs =
(0..1000).map(|n| signal!(cx, n)).collect::<Vec<_>>();
let memo = signal!(cx, {
let sigs = sigs.clone();
move || {
sigs.iter().map(|r| r.get()).sum::<i32>()
}
});
assert_eq!(memo.get(), 499500);
signal!(cx, {
let acc = Rc::clone(&acc);
move || {
acc.set(memo.get());
}
});
assert_eq!(acc.get(), 499500);
sigs[1].update(|n| *n += 1);
sigs[10].update(|n| *n += 1);
sigs[100].update(|n| *n += 1);
assert_eq!(acc.get(), 499503);
assert_eq!(memo.get(), 499503);
});
}
#[bench]
fn l021_deep_creation(b: &mut Bencher) {
use l021::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let signal = create_rw_signal(cx, 0);
let mut memos = Vec::<Memo<usize>>::new();
for _ in 0..1000usize {
if let Some(prev) = memos.last().copied() {
memos.push(create_memo(cx, move |_| prev.get() + 1));
} else {
memos.push(create_memo(cx, move |_| signal.get() + 1));
}
}
})
.dispose()
});
runtime.dispose();
}
#[bench]
fn l021_deep_update(b: &mut Bencher) {
use l021::*;
let runtime = create_runtime();
b.iter(|| {
create_scope(runtime, |cx| {
let signal = create_rw_signal(cx, 0);
let mut memos = Vec::<Memo<usize>>::new();
for _ in 0..1000usize {
if let Some(prev) = memos.last().copied() {
memos.push(create_memo(cx, move |_| prev.get() + 1));
} else {
memos.push(create_memo(cx, move |_| signal.get() + 1));
}
}
signal.set(1);
assert_eq!(memos[999].get(), 1001);
})
.dispose()
});
runtime.dispose();
}
#[bench]
fn l021_narrowing_down(b: &mut Bencher) {
use l021::*;
let runtime = create_runtime();
b.iter(|| {
@@ -183,8 +304,8 @@ fn l0410_narrowing_down(b: &mut Bencher) {
}
#[bench]
fn l0410_fanning_out(b: &mut Bencher) {
use l0410::*;
fn l021_fanning_out(b: &mut Bencher) {
use leptos::*;
let runtime = create_runtime();
b.iter(|| {
@@ -203,8 +324,8 @@ fn l0410_fanning_out(b: &mut Bencher) {
runtime.dispose();
}
#[bench]
fn l0410_narrowing_update(b: &mut Bencher) {
use l0410::*;
fn l021_narrowing_update(b: &mut Bencher) {
use l021::*;
let runtime = create_runtime();
b.iter(|| {
@@ -217,11 +338,11 @@ fn l0410_narrowing_update(b: &mut Bencher) {
let memo = create_memo(cx, move |_| {
reads.iter().map(|r| r.get()).sum::<i32>()
});
assert_eq!(memo.get(), 499500);
assert_eq!(memo(), 499500);
create_isomorphic_effect(cx, {
let acc = Rc::clone(&acc);
move |_| {
acc.set(memo.get());
acc.set(memo());
}
});
assert_eq!(acc.get(), 499500);
@@ -231,7 +352,7 @@ fn l0410_narrowing_update(b: &mut Bencher) {
writes[100].update(|n| *n += 1);
assert_eq!(acc.get(), 499503);
assert_eq!(memo.get(), 499503);
assert_eq!(memo(), 499503);
})
.dispose()
});
@@ -240,8 +361,8 @@ fn l0410_narrowing_update(b: &mut Bencher) {
}
#[bench]
fn l0410_scope_creation_and_disposal(b: &mut Bencher) {
use l0410::*;
fn l021_scope_creation_and_disposal(b: &mut Bencher) {
use l021::*;
let runtime = create_runtime();
b.iter(|| {
@@ -254,7 +375,7 @@ fn l0410_scope_creation_and_disposal(b: &mut Bencher) {
let (r, w) = create_signal(cx, 0);
create_isomorphic_effect(cx, {
move |_| {
acc.set(r.get());
acc.set(r());
}
});
w.update(|n| *n += 1);

View File

@@ -2,14 +2,15 @@ use test::Bencher;
#[bench]
fn leptos_ssr_bench(b: &mut Bencher) {
use leptos::*;
let r = create_runtime();
b.iter(|| {
leptos::leptos_dom::HydrationCtx::reset_id();
use leptos::*;
leptos_dom::HydrationCtx::reset_id();
_ = create_scope(create_runtime(), |cx| {
#[component]
fn Counter(initial: i32) -> impl IntoView {
let (value, set_value) = create_signal(initial);
fn Counter(cx: Scope, initial: i32) -> impl IntoView {
let (value, set_value) = create_signal(cx, initial);
view! {
cx,
<div>
<button on:click=move |_| set_value.update(|value| *value -= 1)>"-1"</button>
<span>"Value: " {move || value().to_string()} "!"</span>
@@ -19,6 +20,7 @@ fn leptos_ssr_bench(b: &mut Bencher) {
}
let rendered = view! {
cx,
<main>
<h1>"Welcome to our benchmark page."</h1>
<p>"Here's some introductory text."</p>
@@ -26,51 +28,14 @@ fn leptos_ssr_bench(b: &mut Bencher) {
<Counter initial=2/>
<Counter initial=3/>
</main>
}.into_view().render_to_string();
}.into_view(cx).render_to_string(cx);
assert_eq!(
rendered,
"<main data-hk=\"0-0-1\"><h1 data-hk=\"0-0-2\">Welcome to our benchmark page.</h1><p data-hk=\"0-0-3\">Here&#x27;s some introductory text.</p><div data-hk=\"0-0-5\"><button data-hk=\"0-0-6\">-1</button><span data-hk=\"0-0-7\">Value: <!>1<!--hk=0-0-8-->!</span><button data-hk=\"0-0-9\">+1</button></div><!--hk=0-0-4--><div data-hk=\"0-0-11\"><button data-hk=\"0-0-12\">-1</button><span data-hk=\"0-0-13\">Value: <!>2<!--hk=0-0-14-->!</span><button data-hk=\"0-0-15\">+1</button></div><!--hk=0-0-10--><div data-hk=\"0-0-17\"><button data-hk=\"0-0-18\">-1</button><span data-hk=\"0-0-19\">Value: <!>3<!--hk=0-0-20-->!</span><button data-hk=\"0-0-21\">+1</button></div><!--hk=0-0-16--></main>"
"<main id=\"_0-1\"><h1 id=\"_0-2\">Welcome to our benchmark page.</h1><p id=\"_0-3\">Here&#x27;s some introductory text.</p><div id=\"_0-3-1\"><button id=\"_0-3-2\">-1</button><span id=\"_0-3-3\">Value: <!>1<!--hk=_0-3-4-->!</span><button id=\"_0-3-5\">+1</button></div><!--hk=_0-3-0--><div id=\"_0-3-5-1\"><button id=\"_0-3-5-2\">-1</button><span id=\"_0-3-5-3\">Value: <!>2<!--hk=_0-3-5-4-->!</span><button id=\"_0-3-5-5\">+1</button></div><!--hk=_0-3-5-0--><div id=\"_0-3-5-5-1\"><button id=\"_0-3-5-5-2\">-1</button><span id=\"_0-3-5-5-3\">Value: <!>3<!--hk=_0-3-5-5-4-->!</span><button id=\"_0-3-5-5-5\">+1</button></div><!--hk=_0-3-5-5-0--></main>"
);
});
});
r.dispose();
}
#[bench]
fn tachys_ssr_bench(b: &mut Bencher) {
use leptos::{create_runtime, create_signal, SignalGet, SignalUpdate};
use tachy_maccy::view;
use tachydom::view::Render;
let rt = create_runtime();
b.iter(|| {
fn counter(initial: i32) -> impl Render {
let (value, set_value) = create_signal(initial);
view! {
<div>
<button on:click=move |_| set_value.update(|value| *value -= 1)>"-1"</button>
<span>"Value: " {move || value().to_string()} "!"</span>
<button on:click=move |_| set_value.update(|value| *value += 1)>"+1"</button>
</div>
}
}
let mut buf = String::with_capacity(1024);
let rendered = view! {
<main>
<h1>"Welcome to our benchmark page."</h1>
<p>"Here's some introductory text."</p>
{counter(1)}
{counter(2)}
{counter(3)}
</main>
};
rendered.to_html(&mut buf, &Default::default());
assert_eq!(
buf,
"<main><h1>Welcome to our benchmark page.</h1><p>Here's some introductory text.</p><div><button>-1</button><span>Value: <!>1<!>!</span><button>+1</button></div><div><button>-1</button><span>Value: <!>2<!>!</span><button>+1</button></div><div><button>-1</button><span>Value: <!>3<!>!</span><button>+1</button></div></main>"
);
});
rt.dispose();
}
#[bench]

View File

@@ -1,7 +1,7 @@
pub use leptos::*;
use miniserde::*;
use wasm_bindgen::JsCast;
use web_sys::HtmlInputElement;
use wasm_bindgen::JsCast;
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Todos(pub Vec<Todo>);
@@ -9,13 +9,13 @@ pub struct Todos(pub Vec<Todo>);
const STORAGE_KEY: &str = "todos-leptos";
impl Todos {
pub fn new() -> Self {
pub fn new(cx: Scope) -> Self {
Self(vec![])
}
pub fn new_with_1000() -> Self {
pub fn new_with_1000(cx: Scope) -> Self {
let todos = (0..1000)
.map(|id| Todo::new(id, format!("Todo #{id}")))
.map(|id| Todo::new(cx, id, format!("Todo #{id}")))
.collect();
Self(todos)
}
@@ -72,17 +72,13 @@ pub struct Todo {
}
impl Todo {
pub fn new(id: usize, title: String) -> Self {
Self::new_with_completed(id, title, false)
pub fn new(cx: Scope, id: usize, title: String) -> Self {
Self::new_with_completed(cx, id, title, false)
}
pub fn new_with_completed(
id: usize,
title: String,
completed: bool,
) -> Self {
let (title, set_title) = create_signal(title);
let (completed, set_completed) = create_signal(completed);
pub fn new_with_completed(cx: Scope, id: usize, title: String, completed: bool) -> Self {
let (title, set_title) = create_signal(cx, title);
let (completed, set_completed) = create_signal(cx, completed);
Self {
id,
title,
@@ -102,7 +98,7 @@ const ESCAPE_KEY: u32 = 27;
const ENTER_KEY: u32 = 13;
#[component]
pub fn TodoMVC(todos: Todos) -> impl IntoView {
pub fn TodoMVC(cx: Scope, todos: Todos) -> impl IntoView {
let mut next_id = todos
.0
.iter()
@@ -111,10 +107,10 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
.map(|last| last + 1)
.unwrap_or(0);
let (todos, set_todos) = create_signal(todos);
provide_context(set_todos);
let (todos, set_todos) = create_signal(cx, todos);
provide_context(cx, set_todos);
let (mode, set_mode) = create_signal(Mode::All);
let (mode, set_mode) = create_signal(cx, Mode::All);
let add_todo = move |ev: web_sys::KeyboardEvent| {
let target = event_target::<HtmlInputElement>(&ev);
@@ -124,7 +120,7 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
let title = event_target_value(&ev);
let title = title.trim();
if !title.is_empty() {
let new = Todo::new(next_id, title.to_string());
let new = Todo::new(cx, next_id, title.to_string());
set_todos.update(|t| t.add(new));
next_id += 1;
target.set_value("");
@@ -132,7 +128,7 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
}
};
let filtered_todos = create_memo::<Vec<Todo>>(move |_| {
let filtered_todos = create_memo::<Vec<Todo>>(cx, move |_| {
todos.with(|todos| match mode.get() {
Mode::All => todos.0.to_vec(),
Mode::Active => todos
@@ -152,7 +148,7 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
// effect to serialize to JSON
// this does reactive reads, so it will automatically serialize on any relevant change
create_effect(move |_| {
create_effect(cx, move |_| {
if let Ok(Some(storage)) = window().local_storage() {
let objs = todos
.get()
@@ -167,7 +163,7 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
}
});
view! {
view! { cx,
<main>
<section class="todoapp">
<header class="header">
@@ -192,8 +188,8 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
<For
each=filtered_todos
key=|todo| todo.id
children=move |todo: Todo| {
view! { <Todo todo=todo.clone()/> }
view=move |cx, todo: Todo| {
view! { cx, <Todo todo=todo.clone()/> }
}
/>
</ul>
@@ -240,14 +236,14 @@ pub fn TodoMVC(todos: Todos) -> impl IntoView {
<p>"Part of " <a href="http://todomvc.com">"TodoMVC"</a></p>
</footer>
</main>
}.into_view()
}.into_view(cx)
}
#[component]
pub fn Todo(todo: Todo) -> impl IntoView {
let (editing, set_editing) = create_signal(false);
let set_todos = use_context::<WriteSignal<Todos>>().unwrap();
//let input = NodeRef::new();
pub fn Todo(cx: Scope, todo: Todo) -> impl IntoView {
let (editing, set_editing) = create_signal(cx, false);
let set_todos = use_context::<WriteSignal<Todos>>(cx).unwrap();
//let input = NodeRef::new(cx);
let save = move |value: &str| {
let value = value.trim();
@@ -259,7 +255,7 @@ pub fn Todo(todo: Todo) -> impl IntoView {
set_editing(false);
};
view! {
view! { cx,
<li class="todo" class:editing=editing class:completed=move || (todo.completed)()>
<div class="view">
<input class="toggle" type="checkbox" prop:checked=move || (todo.completed)()/>
@@ -272,7 +268,7 @@ pub fn Todo(todo: Todo) -> impl IntoView {
{move || {
editing()
.then(|| {
view! {
view! { cx,
<input
class="edit"
class:hidden=move || !(editing)()
@@ -323,8 +319,8 @@ pub struct TodoSerialized {
}
impl TodoSerialized {
pub fn into_todo(self, ) -> Todo {
Todo::new_with_completed(self.id, self.title, self.completed)
pub fn into_todo(self, cx: Scope) -> Todo {
Todo::new_with_completed(cx, self.id, self.title, self.completed)
}
}

View File

@@ -2,7 +2,6 @@ use test::Bencher;
mod leptos;
mod sycamore;
mod tachys;
mod tera;
mod yew;
@@ -13,37 +12,18 @@ fn leptos_todomvc_ssr(b: &mut Bencher) {
b.iter(|| {
use crate::todomvc::leptos::*;
let html = ::leptos::ssr::render_to_string(|| {
view! { <TodoMVC todos=Todos::new()/> }
let html = ::leptos::ssr::render_to_string(|cx| {
view! { cx, <TodoMVC todos=Todos::new(cx)/> }
});
assert!(html.len() > 1);
});
runtime.dispose();
}
#[bench]
fn tachys_todomvc_ssr(b: &mut Bencher) {
use ::leptos::*;
let runtime = create_runtime();
b.iter(|| {
use crate::todomvc::tachys::*;
use tachydom::view::Render;
let mut buf = String::new();
let rendered = TodoMVC(Todos::new());
rendered.to_html(&mut buf, &Default::default());
assert_eq!(
buf,
"<main><section class=\"todoapp\"><header class=\"header\"><h1>todos</h1><input placeholder=\"What needs to be done?\" autofocus=\"\" class=\"new-todo\"></header><section class=\"main hidden\"><input id=\"toggle-all\" type=\"checkbox\" class=\"toggle-all\"><label for=\"toggle-all\">Mark all as complete</label><ul class=\"todo-list\"></ul></section><footer class=\"footer hidden\"><span class=\"todo-count\"><strong>0</strong><!> items<!> left</span><ul class=\"filters\"><li><a href=\"#/\" class=\"selected selected\">All</a></li><li><a href=\"#/active\" class=\"\">Active</a></li><li><a href=\"#/completed\" class=\"\">Completed</a></li></ul><button class=\"clear-completed hidden hidden\">Clear completed</button></footer></section><footer class=\"info\"><p>Double-click to edit a todo</p><p>Created by <a href=\"http://todomvc.com\">Greg Johnston</a></p><p>Part of <a href=\"http://todomvc.com\">TodoMVC</a></p></footer></main>"
);
});
runtime.dispose();
}
#[bench]
fn sycamore_todomvc_ssr(b: &mut Bencher) {
use self::sycamore::*;
use ::sycamore::{prelude::*, *};
use ::sycamore::prelude::*;
use ::sycamore::*;
b.iter(|| {
_ = create_scope(|cx| {
@@ -62,7 +42,8 @@ fn sycamore_todomvc_ssr(b: &mut Bencher) {
#[bench]
fn yew_todomvc_ssr(b: &mut Bencher) {
use self::yew::*;
use ::yew::{prelude::*, ServerRenderer};
use ::yew::prelude::*;
use ::yew::ServerRenderer;
b.iter(|| {
tokio_test::block_on(async {
@@ -79,35 +60,21 @@ fn leptos_todomvc_ssr_with_1000(b: &mut Bencher) {
use self::leptos::*;
use ::leptos::*;
let html = ::leptos::ssr::render_to_string(|| {
let html = ::leptos::ssr::render_to_string(|cx| {
view! {
<TodoMVC todos=Todos::new_with_1000()/>
cx,
<TodoMVC todos=Todos::new_with_1000(cx)/>
}
});
assert!(html.len() > 1);
});
}
#[bench]
fn tachys_todomvc_ssr_with_1000(b: &mut Bencher) {
use ::leptos::*;
let runtime = create_runtime();
b.iter(|| {
use crate::todomvc::tachys::*;
use tachydom::view::Render;
let mut buf = String::new();
let rendered = TodoMVC(Todos::new_with_1000());
rendered.to_html(&mut buf, &Default::default());
assert!(buf.len() > 20_000)
});
runtime.dispose();
}
#[bench]
fn sycamore_todomvc_ssr_with_1000(b: &mut Bencher) {
use self::sycamore::*;
use ::sycamore::{prelude::*, *};
use ::sycamore::prelude::*;
use ::sycamore::*;
b.iter(|| {
_ = create_scope(|cx| {
@@ -126,7 +93,8 @@ fn sycamore_todomvc_ssr_with_1000(b: &mut Bencher) {
#[bench]
fn yew_todomvc_ssr_with_1000(b: &mut Bencher) {
use self::yew::*;
use ::yew::{prelude::*, ServerRenderer};
use ::yew::prelude::*;
use ::yew::ServerRenderer;
b.iter(|| {
tokio_test::block_on(async {
@@ -135,19 +103,4 @@ fn yew_todomvc_ssr_with_1000(b: &mut Bencher) {
assert!(rendered.len() > 1);
});
});
}
#[bench]
fn tera_todomvc_ssr(b: &mut Bencher) {
use ::leptos::*;
let runtime = create_runtime();
b.iter(|| {
use crate::todomvc::leptos::*;
let html = ::leptos::ssr::render_to_string(|| {
view! { <TodoMVC todos=Todos::new()/> }
});
assert!(html.len() > 1);
});
runtime.dispose();
}
}

View File

@@ -1,324 +0,0 @@
pub use leptos_reactive::*;
use miniserde::*;
use tachy_maccy::view;
use tachydom::view::Render;
use wasm_bindgen::JsCast;
use web_sys::HtmlInputElement;
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Todos(pub Vec<Todo>);
const STORAGE_KEY: &str = "todos-leptos";
impl Todos {
pub fn new() -> Self {
Self(vec![])
}
pub fn new_with_1000() -> Self {
let todos = (0..1000)
.map(|id| Todo::new(id, format!("Todo #{id}")))
.collect();
Self(todos)
}
pub fn is_empty(&self) -> bool {
self.0.is_empty()
}
pub fn add(&mut self, todo: Todo) {
self.0.push(todo);
}
pub fn remove(&mut self, id: usize) {
self.0.retain(|todo| todo.id != id);
}
pub fn remaining(&self) -> usize {
self.0.iter().filter(|todo| !(todo.completed)()).count()
}
pub fn completed(&self) -> usize {
self.0.iter().filter(|todo| (todo.completed)()).count()
}
pub fn toggle_all(&self) {
// if all are complete, mark them all active instead
if self.remaining() == 0 {
for todo in &self.0 {
if todo.completed.get() {
(todo.set_completed)(false);
}
}
}
// otherwise, mark them all complete
else {
for todo in &self.0 {
(todo.set_completed)(true);
}
}
}
fn clear_completed(&mut self) {
self.0.retain(|todo| !todo.completed.get());
}
}
#[derive(Debug, PartialEq, Eq, Clone)]
pub struct Todo {
pub id: usize,
pub title: ReadSignal<String>,
pub set_title: WriteSignal<String>,
pub completed: ReadSignal<bool>,
pub set_completed: WriteSignal<bool>,
}
impl Todo {
pub fn new(id: usize, title: String) -> Self {
Self::new_with_completed(id, title, false)
}
pub fn new_with_completed(
id: usize,
title: String,
completed: bool,
) -> Self {
let (title, set_title) = create_signal(title);
let (completed, set_completed) = create_signal(completed);
Self {
id,
title,
set_title,
completed,
set_completed,
}
}
pub fn toggle(&self) {
self.set_completed
.update(|completed| *completed = !*completed);
}
}
const ESCAPE_KEY: u32 = 27;
const ENTER_KEY: u32 = 13;
pub fn TodoMVC(todos: Todos) -> impl Render {
let mut next_id = todos
.0
.iter()
.map(|todo| todo.id)
.max()
.map(|last| last + 1)
.unwrap_or(0);
let (todos, set_todos) = create_signal(todos);
provide_context(set_todos);
let (mode, set_mode) = create_signal(Mode::All);
let add_todo = move |ev: web_sys::KeyboardEvent| {
todo!()
/* let target = event_target::<HtmlInputElement>(&ev);
ev.stop_propagation();
let key_code = ev.unchecked_ref::<web_sys::KeyboardEvent>().key_code();
if key_code == ENTER_KEY {
let title = event_target_value(&ev);
let title = title.trim();
if !title.is_empty() {
let new = Todo::new(next_id, title.to_string());
set_todos.update(|t| t.add(new));
next_id += 1;
target.set_value("");
}
} */
};
let filtered_todos = create_memo::<Vec<Todo>>(move |_| {
todos.with(|todos| match mode.get() {
Mode::All => todos.0.to_vec(),
Mode::Active => todos
.0
.iter()
.filter(|todo| !todo.completed.get())
.cloned()
.collect(),
Mode::Completed => todos
.0
.iter()
.filter(|todo| todo.completed.get())
.cloned()
.collect(),
})
});
// effect to serialize to JSON
// this does reactive reads, so it will automatically serialize on any relevant change
create_effect(move |_| {
()
/* if let Ok(Some(storage)) = window().local_storage() {
let objs = todos
.get()
.0
.iter()
.map(TodoSerialized::from)
.collect::<Vec<_>>();
let json = json::to_string(&objs);
if storage.set_item(STORAGE_KEY, &json).is_err() {
log::error!("error while trying to set item in localStorage");
}
} */
});
view! {
<main>
<section class="todoapp">
<header class="header">
<h1>"todos"</h1>
<input
class="new-todo"
placeholder="What needs to be done?"
autofocus=""
/>
</header>
<section class="main" class:hidden=move || todos.with(|t| t.is_empty())>
<input
id="toggle-all"
class="toggle-all"
r#type="checkbox"
//prop:checked=move || todos.with(|t| t.remaining() > 0)
on:input=move |_| set_todos.update(|t| t.toggle_all())
/>
<label r#for="toggle-all">"Mark all as complete"</label>
<ul class="todo-list">
{filtered_todos.get().into_iter().map(Todo).collect::<Vec<_>>()}
</ul>
</section>
<footer class="footer" class:hidden=move || todos.with(|t| t.is_empty())>
<span class="todo-count">
<strong>{move || todos.with(|t| t.remaining().to_string())}</strong>
{move || if todos.with(|t| t.remaining()) == 1 { " item" } else { " items" }}
" left"
</span>
<ul class="filters">
<li>
<a
href="#/"
class="selected"
class:selected=move || mode() == Mode::All
>
"All"
</a>
</li>
<li>
<a href="#/active" class:selected=move || mode() == Mode::Active>
"Active"
</a>
</li>
<li>
<a href="#/completed" class:selected=move || mode() == Mode::Completed>
"Completed"
</a>
</li>
</ul>
<button
class="clear-completed hidden"
class:hidden=move || todos.with(|t| t.completed() == 0)
on:click=move |_| set_todos.update(|t| t.clear_completed())
>
"Clear completed"
</button>
</footer>
</section>
<footer class="info">
<p>"Double-click to edit a todo"</p>
<p>"Created by " <a href="http://todomvc.com">"Greg Johnston"</a></p>
<p>"Part of " <a href="http://todomvc.com">"TodoMVC"</a></p>
</footer>
</main>
}
}
pub fn Todo(todo: Todo) -> impl Render {
let (editing, set_editing) = create_signal(false);
let set_todos = use_context::<WriteSignal<Todos>>().unwrap();
//let input = NodeRef::new();
let save = move |value: &str| {
let value = value.trim();
if value.is_empty() {
set_todos.update(|t| t.remove(todo.id));
} else {
(todo.set_title)(value.to_string());
}
set_editing(false);
};
view! {
<li class="todo" class:editing=editing class:completed=move || (todo.completed)()>
/* <div class="view">
<input class="toggle" r#type="checkbox"/>
<label on:dblclick=move |_| set_editing(true)>{move || todo.title.get()}</label>
<button
class="destroy"
on:click=move |_| set_todos.update(|t| t.remove(todo.id))
></button>
</div>
{move || {
editing()
.then(|| {
view! {
<input
class="edit"
class:hidden=move || !(editing)()
/>
}
})
}} */
</li>
}
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Mode {
Active,
Completed,
All,
}
impl Default for Mode {
fn default() -> Self {
Mode::All
}
}
pub fn route(hash: &str) -> Mode {
match hash {
"/active" => Mode::Active,
"/completed" => Mode::Completed,
_ => Mode::All,
}
}
#[derive(Serialize, Deserialize)]
pub struct TodoSerialized {
pub id: usize,
pub title: String,
pub completed: bool,
}
impl TodoSerialized {
pub fn into_todo(self) -> Todo {
Todo::new_with_completed(self.id, self.title, self.completed)
}
}
impl From<&Todo> for TodoSerialized {
fn from(todo: &Todo) -> Self {
Self {
id: todo.id,
title: todo.title.get(),
completed: (todo.completed)(),
}
}
}

View File

@@ -87,7 +87,7 @@ static TEMPLATE: &str = r#"<main>
</main>"#;
#[bench]
fn tera_todomvc_ssr(b: &mut Bencher) {
fn tera_todomvc(b: &mut Bencher) {
use serde::{Deserialize, Serialize};
use tera::*;
@@ -127,7 +127,7 @@ fn tera_todomvc_ssr(b: &mut Bencher) {
}
#[bench]
fn tera_todomvc_ssr_1000(b: &mut Bencher) {
fn tera_todomvc_1000(b: &mut Bencher) {
use serde::{Deserialize, Serialize};
use tera::*;
@@ -174,4 +174,4 @@ fn tera_todomvc_ssr_1000(b: &mut Bencher) {
let _ = TERA.render("template.html", &ctx).unwrap();
});
}
}

View File

@@ -1,7 +0,0 @@
[tasks.check]
alias = "check-all"
[tasks.check-all]
command = "cargo"
args = ["+nightly", "check-all-features"]
install_crate = "cargo-all-features"

View File

@@ -1,11 +0,0 @@
[tasks.lint]
dependencies = ["check-format-flow", "clippy-each-feature"]
[tasks.check-format]
env = { LEPTOS_PROJECT_DIRECTORY = "../" }
args = ["fmt", "--", "--check", "--config-path", "${LEPTOS_PROJECT_DIRECTORY}"]
[tasks.clippy-each-feature]
dependencies = ["install-clippy"]
command = "cargo"
args = ["hack", "clippy", "--all", "--each-feature", "--no-dev-deps"]

View File

@@ -1,15 +0,0 @@
extend = [
{ path = "./check.toml" },
{ path = "./lint.toml" },
{ path = "./test.toml" },
]
[env]
RUSTFLAGS = ""
LEPTOS_OUTPUT_NAME = "ci" # allows examples to check/build without cargo-leptos
[env.github-actions]
RUSTFLAGS = "-D warnings"
[tasks.ci]
dependencies = ["lint", "test"]

View File

@@ -1,7 +0,0 @@
[tasks.test]
alias = "test-all"
[tasks.test-all]
command = "cargo"
args = ["+nightly", "test-all-features"]
install_crate = "cargo-all-features"

View File

@@ -9,10 +9,10 @@ This document is intended as a running list of common issues, with example code
**Issue**: Sometimes you want to update a reactive signal in a way that depends on another signal.
```rust
let (a, set_a) = create_signal(0);
let (b, set_b) = create_signal(false);
let (a, set_a) = create_signal(cx, 0);
let (b, set_b) = create_signal(cx, false);
create_effect(move |_| {
create_effect(cx, move |_| {
if a() > 5 {
set_b(true);
}
@@ -24,7 +24,7 @@ This creates an inefficient chain of updates, and can easily lead to infinite lo
**Solution**: Follow the rule, _What can be derived, should be derived._ In this case, this has the benefit of massively reducing the code size, too!
```rust
let (a, set_a) = create_signal(0);
let (a, set_a) = create_signal(cx, 0);
let b = move || a () > 5;
```
@@ -34,19 +34,19 @@ Sometimes you have nested signals: for example, hash-map that can change over ti
```rust
#[component]
pub fn App() -> impl IntoView {
let resources = create_rw_signal(HashMap::new());
pub fn App(cx: Scope) -> impl IntoView {
let resources = create_rw_signal(cx, HashMap::new());
let update = move |id: usize| {
resources.update(|resources| {
resources
.entry(id)
.or_insert_with(|| create_rw_signal(0))
.or_insert_with(|| create_rw_signal(cx, 0))
.update(|amount| *amount += 1)
})
};
view! {
view! { cx,
<div>
<pre>{move || format!("{:#?}", resources.get().into_iter().map(|(id, resource)| (id, resource.get())).collect::<Vec<_>>())}</pre>
<button on:click=move |_| update(1)>"+"</button>
@@ -55,17 +55,17 @@ pub fn App() -> impl IntoView {
}
```
Clicking the button twice will cause a panic, because of the nested signal _read_. Calling the `update` function on `resources` immediately takes out a mutable borrow on `resources`, then updates the `resource` signal—which re-runs the effect that reads from the signals, which tries to immutably access `resources` and panics. It's the nested update here which causes a problem, because the inner update triggers and effect that tries to read both signals while the outer is still updating.
Clicking the button twice will cause a panic, because of the nested signal *read*. Calling the `update` function on `resources` immediately takes out a mutable borrow on `resources`, then updates the `resource` signal—which re-runs the effect that reads from the signals, which tries to immutably access `resources` and panics. It's the nested update here which causes a problem, because the inner update triggers and effect that tries to read both signals while the outer is still updating.
You can fix this fairly easily by using the [`batch()`](https://docs.rs/leptos/latest/leptos/fn.batch.html) method:
You can fix this fairly easily by using the [`Scope::batch()`](https://docs.rs/leptos/latest/leptos/struct.Scope.html#method.batch) method:
```rust
let update = move |id: usize| {
batch(move || {
cx.batch(move || {
resources.update(|resources| {
resources
.entry(id)
.or_insert_with(|| create_rw_signal(0))
.or_insert_with(|| create_rw_signal(cx, 0))
.update(|amount| *amount += 1)
})
});
@@ -83,11 +83,11 @@ Many DOM attributes can be updated either by setting an attribute on the DOM nod
This means that in practice, attributes like `value` or `checked` on an `<input/>` element only update the _default_ value for the `<input/>`. If you want to reactively update the value, you should use `prop:value` instead to set the `value` property.
```rust
let (a, set_a) = create_signal("Starting value".to_string());
let (a, set_a) = create_signal(cx, "Starting value".to_string());
let on_input = move |ev| set_a(event_target_value(&ev));
view! {
cx,
// ❌ reactivity doesn't work as expected: typing only updates the default
// of each input, so if you start typing in the second input, it won't
// update the first one
@@ -97,11 +97,11 @@ view! {
```
```rust
let (a, set_a) = create_signal("Starting value".to_string());
let (a, set_a) = create_signal(cx, "Starting value".to_string());
let on_input = move |ev| set_a(event_target_value(&ev));
view! {
cx,
// ✅ works as intended by setting the value *property*
<input prop:value=a on:input=on_input />
<input prop:value=a on:input=on_input />

View File

@@ -1,10 +0,0 @@
[output.html]
additional-css = ["./mdbook-admonish.css"]
[output.html.playground]
runnable = false
[preprocessor]
[preprocessor.admonish]
command = "mdbook-admonish"
assets_version = "2.0.2" # do not edit: managed by `mdbook-admonish install`

View File

@@ -1,353 +0,0 @@
@charset "UTF-8";
:root {
--md-admonition-icon--note:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M20.71 7.04c.39-.39.39-1.04 0-1.41l-2.34-2.34c-.37-.39-1.02-.39-1.41 0l-1.84 1.83 3.75 3.75M3 17.25V21h3.75L17.81 9.93l-3.75-3.75L3 17.25z'/></svg>");
--md-admonition-icon--abstract:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M17 9H7V7h10m0 6H7v-2h10m-3 6H7v-2h7M12 3a1 1 0 0 1 1 1 1 1 0 0 1-1 1 1 1 0 0 1-1-1 1 1 0 0 1 1-1m7 0h-4.18C14.4 1.84 13.3 1 12 1c-1.3 0-2.4.84-2.82 2H5a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2V5a2 2 0 0 0-2-2z'/></svg>");
--md-admonition-icon--info:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M13 9h-2V7h2m0 10h-2v-6h2m-1-9A10 10 0 0 0 2 12a10 10 0 0 0 10 10 10 10 0 0 0 10-10A10 10 0 0 0 12 2z'/></svg>");
--md-admonition-icon--tip:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M17.66 11.2c-.23-.3-.51-.56-.77-.82-.67-.6-1.43-1.03-2.07-1.66C13.33 7.26 13 4.85 13.95 3c-.95.23-1.78.75-2.49 1.32-2.59 2.08-3.61 5.75-2.39 8.9.04.1.08.2.08.33 0 .22-.15.42-.35.5-.23.1-.47.04-.66-.12a.58.58 0 0 1-.14-.17c-1.13-1.43-1.31-3.48-.55-5.12C5.78 10 4.87 12.3 5 14.47c.06.5.12 1 .29 1.5.14.6.41 1.2.71 1.73 1.08 1.73 2.95 2.97 4.96 3.22 2.14.27 4.43-.12 6.07-1.6 1.83-1.66 2.47-4.32 1.53-6.6l-.13-.26c-.21-.46-.77-1.26-.77-1.26m-3.16 6.3c-.28.24-.74.5-1.1.6-1.12.4-2.24-.16-2.9-.82 1.19-.28 1.9-1.16 2.11-2.05.17-.8-.15-1.46-.28-2.23-.12-.74-.1-1.37.17-2.06.19.38.39.76.63 1.06.77 1 1.98 1.44 2.24 2.8.04.14.06.28.06.43.03.82-.33 1.72-.93 2.27z'/></svg>");
--md-admonition-icon--success:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='m9 20.42-6.21-6.21 2.83-2.83L9 14.77l9.88-9.89 2.83 2.83L9 20.42z'/></svg>");
--md-admonition-icon--question:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='m15.07 11.25-.9.92C13.45 12.89 13 13.5 13 15h-2v-.5c0-1.11.45-2.11 1.17-2.83l1.24-1.26c.37-.36.59-.86.59-1.41a2 2 0 0 0-2-2 2 2 0 0 0-2 2H8a4 4 0 0 1 4-4 4 4 0 0 1 4 4 3.2 3.2 0 0 1-.93 2.25M13 19h-2v-2h2M12 2A10 10 0 0 0 2 12a10 10 0 0 0 10 10 10 10 0 0 0 10-10c0-5.53-4.5-10-10-10z'/></svg>");
--md-admonition-icon--warning:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M13 14h-2V9h2m0 9h-2v-2h2M1 21h22L12 2 1 21z'/></svg>");
--md-admonition-icon--failure:
url("data:image/svg+xml;charset=utf-8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M20 6.91 17.09 4 12 9.09 6.91 4 4 6.91 9.09 12 4 17.09 6.91 20 12 14.91 17.09 20 20 17.09 14.91 12 20 6.91z'/></svg>");
--md-admonition-icon--danger:
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--md-admonition-icon--bug:
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View File

@@ -1,22 +1,20 @@
# Introduction
This book is intended as an introduction to the [Leptos](https://github.com/leptos-rs/leptos) Web framework.
It will walk through the fundamental concepts you need to build applications,
This book is intended as an introduction to the [Leptos](https://github.com/leptos-rs/leptos) Web framework.
It will walk through the fundamental concepts you need to build applications,
beginning with a simple application rendered in the browser, and building toward a
full-stack application with server-side rendering and hydration.
The guide doesnt assume you know anything about fine-grained reactivity or the
details of modern Web frameworks. It does assume you are familiar with the Rust
The guide doesnt assume you know anything about fine-grained reactivity or the
details of modern Web frameworks. It does assume you are familiar with the Rust
programming language, HTML, CSS, and the DOM and basic Web APIs.
Leptos is most similar to frameworks like [Solid](https://www.solidjs.com) (JavaScript)
and [Sycamore](https://sycamore-rs.netlify.app/) (Rust). There are some similarities
to other frameworks like React (JavaScript), Svelte (JavaScript), Yew (Rust), and
Dioxus (Rust), so knowledge of one of those frameworks may also make it easier to
Leptos is most similar to frameworks like [Solid](https://www.solidjs.com) (JavaScript)
and [Sycamore](https://sycamore-rs.netlify.app/) (Rust). There are some similarities
to other frameworks like React (JavaScript), Svelte (JavaScript), Yew (Rust), and
Dioxus (Rust), so knowledge of one of those frameworks may also make it easier to
understand Leptos.
You can find more detailed docs for each part of the API at [Docs.rs](https://docs.rs/leptos/latest/leptos/).
**Important Note**: This current version of the book reflects the `0.5.1` release. The CodeSandbox versions of the examples still reflect `0.4` and earlier APIs and are in the process of being updated.
> The source code for the book is available [here](https://github.com/leptos-rs/leptos/tree/main/docs/book). PRs for typos or clarification are always welcome.
**The guide is a work in progress.**

View File

@@ -14,51 +14,24 @@ If you dont already have it installed, you can install Trunk by running
cargo install trunk
```
Create a basic Rust project
Create a basic Rust binary project
```bash
cargo init leptos-tutorial
```
`cd` into your new `leptos-tutorial` project and add `leptos` as a dependency
```bash
cargo add leptos --features=csr,nightly
```
> **Note**: This version of the book reflects the Leptos 0.5 release. The CodeSandbox examples have not yet been updated from 0.4 and earlier versions.
Or you can leave off `nightly` if you're using stable Rust
```bash
cargo add leptos --features=csr
```
> Using `nightly` Rust, and the `nightly` feature in Leptos enables the function-call syntax for signal getters and setters that is used in most of this book.
>
> To use nightly Rust, you can either opt into nightly for all your Rust projects by running
> We recommend using `nightly` Rust, as it enables [a few nice features](https://github.com/leptos-rs/leptos#nightly-note). To use `nightly` Rust with WebAssembly, you can run
>
> ```bash
> rustup toolchain install nightly
> rustup default nightly
> rustup target add wasm32-unknown-unknown
> ```
>
> or only for this project
>
> ```bash
> rustup toolchain install nightly
> cd <into your project>
> rustup override set nightly
> ```
>
> [See here for more details.](https://doc.rust-lang.org/book/appendix-07-nightly-rust.html)
>
> If youd rather use stable Rust with Leptos, you can do that too. In the guide and examples, youll just use the [`ReadSignal::get()`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html#impl-SignalGet%3CT%3E-for-ReadSignal%3CT%3E) and [`WriteSignal::set()`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html#impl-SignalGet%3CT%3E-for-ReadSignal%3CT%3E) methods instead of calling signal getters and setters as functions.
Make sure you've added the `wasm32-unknown-unknown` target so that Rust can compile your code to WebAssembly to run in the browser.
`cd` into your new `leptos-tutorial` project and add `leptos` as a dependency
```bash
rustup target add wasm32-unknown-unknown
cargo add leptos
```
Create a simple `index.html` in the root of the `leptos-tutorial` directory
@@ -77,7 +50,7 @@ And add a simple “Hello, world!” to your `main.rs`
use leptos::*;
fn main() {
mount_to_body(|| view! { <p>"Hello, world!"</p> })
mount_to_body(|cx| view! { cx, <p>"Hello, world!"</p> })
}
```

View File

@@ -0,0 +1,112 @@
# Responding to Changes with `create_effect`
Believe it or not, weve made it this far without having mentioned half of the reactive system: effects.
Leptos is built on a fine-grained reactive system, which means that individual reactive values (“signals,” sometimes known as observables) trigger rerunning the code that reacts to them (“effects,” sometimes known as observers). These two halves of the reactive system are inter-dependent. Without effects, signals can change within the reactive system but never be observed in a way that interacts with the outside world. Without signals, effects run once but never again, as theres no observable value to subscribe to.
[`create_effect`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_effect.html) takes a function as its argument. It immediately runs the function. If you access any reactive signal inside that function, it registers the fact that the effect depends on that signal with the reactive runtime. Whenever one of the signals that the effect depends on changes, the effect runs again.
```rust
let (a, set_a) = create_signal(cx, 0);
let (b, set_b) = create_signal(cx, 0);
create_effect(cx, move |_| {
// immediately prints "Value: 0" and subscribes to `a`
log::debug!("Value: {}", a());
});
```
The effect function is called with an argument containing whatever value it returned the last time it ran. On the initial run, this is `None`.
By default, effects **do not run on the server**. This means you can call browser-specific APIs within the effect function without causing issues. If you need an effect to run on the server, use [`create_isomorphic_effect`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_isomorphic_effect.html).
## Autotracking and Dynamic Dependencies
If youre familiar with a framework like React, you might notice one key difference. React and similar frameworks typically require you to pass a “dependency array,” an explicit set of variables that determine when the effect should rerun.
Because Leptos comes from the tradition of synchronous reactive programming, we dont need this explicit dependency list. Instead, we automatically track dependencies depending on which signals are accessed within the effect.
This has two effects (no pun intended). Dependencies are
1. **Automatic**: You dont need to maintain a dependency list, or worry about what should or shouldnt be included. The framework simply tracks which signals might cause the effect to rerun, and handles it for you.
2. **Dynamic**: The dependency list is cleared and updated every time the effect runs. If your effect contains a conditional (for example), only signals that are used in the current branch are tracked. This means that effects rerun the absolute minimum number of times.
> If this sounds like magic, and if you want a deep dive into how automatic dependency tracking works, [check out this video](https://www.youtube.com/watch?v=GWB3vTWeLd4). (Apologies for the low volume!)
## Effects as Zero-Cost-ish Abstraction
While theyre not a “zero-cost abstraction” in the most technical sense—they require some additional memory use, exist at runtime, etc.—at a higher level, from the perspective of whatever expensive API calls or other work youre doing within them, effects are a zero-cost abstraction. They rerun the absolute minimum number of times necessary, given how youve described them.
Imagine that Im creating some kind of chat software, and I want people to be able to display their full name, or just their first name, and to notify the server whenever their name changes:
```rust
let (first, set_first) = create_signal(cx, String::new());
let (last, set_last) = create_signal(cx, String::new());
let (use_last, set_use_last) = create_signal(cx, true);
// this will add the name to the log
// any time one of the source signals changes
create_effect(cx, move |_| {
log(
cx,
if use_last() {
format!("{} {}", first(), last())
} else {
first()
},
)
});
```
If `use_last` is `true`, effect should rerun whenever `first`, `last`, or `use_last` changes. But if I toggle `use_last` to `false`, a change in `last` will never cause the full name to change. In fact, `last` will be removed from the dependency list until `use_last` toggles again. This saves us from sending multiple unnecessary requests to the API if I change `last` multiple times while `use_last` is still `false`.
## To `create_effect`, or not to `create_effect`?
Effects are intended to run _side-effects_ of the system, not to synchronize state _within_ the system. In other words: dont write to signals within effects.
If you need to define a signal that depends on the value of other signals, use a derived signal or [`create_memo`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_memo.html).
If you need to synchronize some reactive value with the non-reactive world outside—like a web API, the console, the filesystem, or the DOM—create an effect.
> If youre curious for more information about when you should and shouldnt use `create_effect`, [check out this video](https://www.youtube.com/watch?v=aQOFJQ2JkvQ) for a more in-depth consideration!
## Effects and Rendering
Weve managed to get this far without mentioning effects because theyre built into the Leptos DOM renderer. Weve seen that you can create a signal and pass it into the `view` macro, and it will update the relevant DOM node whenever the signal changes:
```rust
let (count, set_count) = create_signal(cx, 0);
view! { cx,
<p>{count}</p>
}
```
This works because the framework essentially creates an effect wrapping this update. You can imagine Leptos translating this view into something like this:
```rust
let (count, set_count) = create_signal(cx, 0);
// create a DOM element
let p = create_element("p");
// create an effect to reactively update the text
create_effect(cx, move |prev_value| {
// first, access the signals value and convert it to a string
let text = count().to_string();
// if this is different from the previous value, update the node
if prev_value != Some(text) {
p.set_text_content(&text);
}
// return this value so we can memoize the next update
text
});
```
Every time `count` is updated, this effect wil rerun. This is what allows reactive, fine-grained updates to the DOM.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/serene-thompson-40974n?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/serene-thompson-40974n?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -1,8 +1,8 @@
# Global State Management
So far, we've only been working with local state in components, and weve seen how to coordinate state between parent and child components. On occasion, there are times where people look for a more general solution for global state management that can work throughout an application.
In general, **you do not need this chapter.** The typical pattern is to compose your application out of components, each of which manages its own local state, not to store all state in a global structure. However, there are some cases (like theming, saving user settings, or sharing data between components in different parts of your UI) in which you may want to use some kind of global state management.
So far, we've only been working with local state in components
We've only seen how to communicate between parent and child components
But there are also more general ways to manage global state
The three best approaches to global state are
@@ -12,32 +12,34 @@ The three best approaches to global state are
## Option #1: URL as Global State
In many ways, the URL is actually the best way to store global state. It can be accessed from any component, anywhere in your tree. There are native HTML elements like `<form>` and `<a>` that exist solely to update the URL. And it persists across page reloads and between devices; you can share a URL with a friend or send it from your phone to your laptop and any state stored in it will be replicated.
The next few sections of the tutorial will be about the router, and well get much more into these topics.
But for now, we'll just look at options #2 and #3.
The next few sections of the tutorial will be about the router.
So for now, we'll just look at options #2 and #3.
## Option #2: Passing Signals through Context
In the section on [parent-child communication](view/08_parent_child.md), we saw that you can use `provide_context` to pass signal from a parent component to a child, and `use_context` to read it in the child. But `provide_context` works across any distance. If you want to create a global signal that holds some piece of state, you can provide it and access it via context anywhere in the descendants of the component where you provide it.
In virtual DOM libraries like React, using the Context API to manage global
state is a bad idea: because the entire app exists in a tree, changing
some value provided high up in the tree can cause the whole app to render.
A signal provided via context only causes reactive updates where it is read, not in any of the components in between, so it maintains the power of fine-grained reactive updates, even at a distance.
In fine-grained reactive libraries like Leptos, this is simply not the case.
You can create a signal in the root of your app and pass it down to other
components using provide_context(). Changing it will only cause rerendering
in the specific places it is actually used, not the whole app.
We start by creating a signal in the root of the app and providing it to
all its children and descendants using `provide_context`.
```rust
#[component]
fn App() -> impl IntoView {
fn App(cx: Scope) -> impl IntoView {
// here we create a signal in the root that can be consumed
// anywhere in the app.
let (count, set_count) = create_signal(0);
let (count, set_count) = create_signal(cx, 0);
// we'll pass the setter to specific components,
// but provide the count itself to the whole app via context
provide_context(count);
provide_context(cx, count);
view! {
view! { cx,
// SetterButton is allowed to modify the count
<SetterButton set_count/>
// These consumers can only read from it
@@ -57,14 +59,14 @@ fn App() -> impl IntoView {
```rust
/// A component that does some "fancy" math with the global count
#[component]
fn FancyMath() -> impl IntoView {
fn FancyMath(cx: Scope) -> impl IntoView {
// here we consume the global count signal with `use_context`
let count = use_context::<ReadSignal<u32>>()
let count = use_context::<ReadSignal<u32>>(cx)
// we know we just provided this in the parent component
.expect("there to be a `count` signal provided");
let is_even = move || count() & 1 == 0;
view! {
view! { cx,
<div class="consumer blue">
"The number "
<strong>{count}</strong>
@@ -79,76 +81,65 @@ fn FancyMath() -> impl IntoView {
}
```
Note that this same pattern can be applied to more complex state. If you have multiple fields you want to update independently, you can do that by providing some struct of signals:
This kind of “provide a signal in a parent, consume it in a child” should be familiar
from the chapter on [parent-child interactions](./view/08_parent_child.md). The same
pattern you use to communicate between parents and children works for grandparents and
grandchildren, or any ancestors and descendants: in other words, between “global” state
in the root component of your app and any other components anywhere else in the app.
Because of the fine-grained nature of updates, this is usually all you need. However,
in some cases with more complex state changes, you may want to use a slightly more
structured approach to global state.
## Option #3: Create a Global State Struct
You can use this approach to build a single global data structure
that holds the state for your whole app, and then access it by
taking fine-grained slices using
[`create_slice`](https://docs.rs/leptos/latest/leptos/fn.create_slice.html)
or [`create_memo`](https://docs.rs/leptos/latest/leptos/fn.create_memo.html),
so that changing one part of the state doesn't cause parts of your
app that depend on other parts of the state to change.
You can begin by defining a simple state struct:
```rust
#[derive(Copy, Clone, Debug)]
#[derive(Default, Clone, Debug)]
struct GlobalState {
count: RwSignal<i32>,
name: RwSignal<String>
}
impl GlobalState {
pub fn new() -> Self {
Self {
count: create_rw_signal(0),
name: create_rw_signal("Bob".to_string())
}
}
}
#[component]
fn App() -> impl IntoView {
provide_context(GlobalState::new());
// etc.
count: u32,
name: String,
}
```
## Option #3: Create a Global State Struct and Slices
You may find it cumbersome to wrap each field of a structure in a separate signal like this. In some cases, it can be useful to create a plain struct with non-reactive fields, and then wrap that in a signal.
Provide it in the root of your app so its available everywhere.
```rust
#[derive(Copy, Clone, Debug, Default)]
struct GlobalState {
count: i32,
name: String
}
#[component]
fn App() -> impl IntoView {
provide_context(create_rw_signal(GlobalState::default()));
fn App(cx: Scope) -> impl IntoView {
// we'll provide a single signal that holds the whole state
// each component will be responsible for creating its own "lens" into it
let state = create_rw_signal(cx, GlobalState::default());
provide_context(cx, state);
// etc.
// ...
}
```
But theres a problem: because our whole state is wrapped in one signal, updating the value of one field will cause reactive updates in parts of the UI that only depend on the other.
```rust
let state = expect_context::<RwSignal<GlobalState>>();
view! {
<button on:click=move |_| state.update(|n| *n += 1)>"+1"</button>
<p>{move || state.with(|state| state.name.clone())}</p>
}
```
In this example, clicking the button will cause the text inside `<p>` to be updated, cloning `state.name` again! Because signals are the atomic unit of reactivity, updating any field of the signal triggers updates to everything that depends on the signal.
Theres a better way. You can take fine-grained, reactive slices by using [`create_memo`](https://docs.rs/leptos/latest/leptos/fn.create_memo.html) or [`create_slice`](https://docs.rs/leptos/latest/leptos/fn.create_slice.html) (which uses `create_memo` but also provides a setter). “Memoizing” a value means creating a new reactive value which will only update when it changes. “Memoizing a slice” means creating a new reactive value which will only update when some field of the state struct updates.
Here, instead of reading from the state signal directly, we create “slices” of that state with fine-grained updates via `create_slice`. Each slice signal only updates when the particular piece of the larger struct it accesses updates. This means you can create a single root signal, and then take independent, fine-grained slices of it in different components, each of which can update without notifying the others of changes.
Then child components can access “slices” of that state with fine-grained
updates via `create_slice`. Each slice signal only updates when the particular
piece of the larger struct it accesses updates. This means you can create a single
root signal, and then take independent, fine-grained slices of it in different
components, each of which can update without notifying the others of changes.
```rust
/// A component that updates the count in the global state.
#[component]
fn GlobalStateCounter() -> impl IntoView {
let state = expect_context::<RwSignal<GlobalState>>();
fn GlobalStateCounter(cx: Scope) -> impl IntoView {
let state = use_context::<RwSignal<GlobalState>>(cx).expect("state to have been provided");
// `create_slice` lets us create a "lens" into the data
let (count, set_count) = create_slice(
cx,
// we take a slice *from* `state`
state,
// our getter returns a "slice" of the data
@@ -157,7 +148,7 @@ fn GlobalStateCounter() -> impl IntoView {
|state, n| state.count = n,
);
view! {
view! { cx,
<div class="consumer blue">
<button
on:click=move |_| {
@@ -178,225 +169,6 @@ somewhere else that only takes `state.name`, clicking the button wont cause
that other slice to update. This allows you to combine the benefits of a top-down
data flow and of fine-grained reactive updates.
> **Note**: There are some significant drawbacks to this approach. Both signals and memos need to own their values, so a memo will need to clone the fields value on every change. The most natural way to manage state in a framework like Leptos is always to provide signals that are as locally-scoped and fine-grained as they can be, not to hoist everything up into global state. But when you _do_ need some kind of global state, `create_slice` can be a useful tool.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/1-basic-component-forked-8bte19?selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D&file=%2Fsrc%2Fmain.rs)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/15-global-state-0-5-8c2ff6?file=%2Fsrc%2Fmain.rs%3A1%2C2)
<iframe src="https://codesandbox.io/p/sandbox/15-global-state-0-5-8c2ff6?file=%2Fsrc%2Fmain.rs%3A1%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
// So far, we've only been working with local state in components
// We've only seen how to communicate between parent and child components
// But there are also more general ways to manage global state
//
// The three best approaches to global state are
// 1. Using the router to drive global state via the URL
// 2. Passing signals through context
// 3. Creating a global state struct and creating lenses into it with `create_slice`
//
// Option #1: URL as Global State
// The next few sections of the tutorial will be about the router.
// So for now, we'll just look at options #2 and #3.
// Option #2: Pass Signals through Context
//
// In virtual DOM libraries like React, using the Context API to manage global
// state is a bad idea: because the entire app exists in a tree, changing
// some value provided high up in the tree can cause the whole app to render.
//
// In fine-grained reactive libraries like Leptos, this is simply not the case.
// You can create a signal in the root of your app and pass it down to other
// components using provide_context(). Changing it will only cause rerendering
// in the specific places it is actually used, not the whole app.
#[component]
fn Option2() -> impl IntoView {
// here we create a signal in the root that can be consumed
// anywhere in the app.
let (count, set_count) = create_signal(0);
// we'll pass the setter to specific components,
// but provide the count itself to the whole app via context
provide_context(count);
view! {
<h1>"Option 2: Passing Signals"</h1>
// SetterButton is allowed to modify the count
<SetterButton set_count/>
// These consumers can only read from it
// But we could give them write access by passing `set_count` if we wanted
<div style="display: flex">
<FancyMath/>
<ListItems/>
</div>
}
}
/// A button that increments our global counter.
#[component]
fn SetterButton(set_count: WriteSignal<u32>) -> impl IntoView {
view! {
<div class="provider red">
<button on:click=move |_| set_count.update(|count| *count += 1)>
"Increment Global Count"
</button>
</div>
}
}
/// A component that does some "fancy" math with the global count
#[component]
fn FancyMath() -> impl IntoView {
// here we consume the global count signal with `use_context`
let count = use_context::<ReadSignal<u32>>()
// we know we just provided this in the parent component
.expect("there to be a `count` signal provided");
let is_even = move || count() & 1 == 0;
view! {
<div class="consumer blue">
"The number "
<strong>{count}</strong>
{move || if is_even() {
" is"
} else {
" is not"
}}
" even."
</div>
}
}
/// A component that shows a list of items generated from the global count.
#[component]
fn ListItems() -> impl IntoView {
// again, consume the global count signal with `use_context`
let count = use_context::<ReadSignal<u32>>().expect("there to be a `count` signal provided");
let squares = move || {
(0..count())
.map(|n| view! { <li>{n}<sup>"2"</sup> " is " {n * n}</li> })
.collect::<Vec<_>>()
};
view! {
<div class="consumer green">
<ul>{squares}</ul>
</div>
}
}
// Option #3: Create a Global State Struct
//
// You can use this approach to build a single global data structure
// that holds the state for your whole app, and then access it by
// taking fine-grained slices using `create_slice` or `create_memo`,
// so that changing one part of the state doesn't cause parts of your
// app that depend on other parts of the state to change.
#[derive(Default, Clone, Debug)]
struct GlobalState {
count: u32,
name: String,
}
#[component]
fn Option3() -> impl IntoView {
// we'll provide a single signal that holds the whole state
// each component will be responsible for creating its own "lens" into it
let state = create_rw_signal(GlobalState::default());
provide_context(state);
view! {
<h1>"Option 3: Passing Signals"</h1>
<div class="red consumer" style="width: 100%">
<h2>"Current Global State"</h2>
<pre>
{move || {
format!("{:#?}", state.get())
}}
</pre>
</div>
<div style="display: flex">
<GlobalStateCounter/>
<GlobalStateInput/>
</div>
}
}
/// A component that updates the count in the global state.
#[component]
fn GlobalStateCounter() -> impl IntoView {
let state = use_context::<RwSignal<GlobalState>>().expect("state to have been provided");
// `create_slice` lets us create a "lens" into the data
let (count, set_count) = create_slice(
// we take a slice *from* `state`
state,
// our getter returns a "slice" of the data
|state| state.count,
// our setter describes how to mutate that slice, given a new value
|state, n| state.count = n,
);
view! {
<div class="consumer blue">
<button
on:click=move |_| {
set_count(count() + 1);
}
>
"Increment Global Count"
</button>
<br/>
<span>"Count is: " {count}</span>
</div>
}
}
/// A component that updates the count in the global state.
#[component]
fn GlobalStateInput() -> impl IntoView {
let state = use_context::<RwSignal<GlobalState>>().expect("state to have been provided");
// this slice is completely independent of the `count` slice
// that we created in the other component
// neither of them will cause the other to rerun
let (name, set_name) = create_slice(
// we take a slice *from* `state`
state,
// our getter returns a "slice" of the data
|state| state.name.clone(),
// our setter describes how to mutate that slice, given a new value
|state, n| state.name = n,
);
view! {
<div class="consumer green">
<input
type="text"
prop:value=name
on:input=move |ev| {
set_name(event_target_value(&ev));
}
/>
<br/>
<span>"Name is: " {name}</span>
</div>
}
}
// This `main` function is the entry point into the app
// It just mounts our component to the <body>
// Because we defined it as `fn App`, we can now use it in a
// template as <App/>
fn main() {
leptos::mount_to_body(|| view! { <Option2/><Option3/> })
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/1-basic-component-forked-8bte19?selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D&file=%2Fsrc%2Fmain.rs" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -7,17 +7,12 @@
- [Dynamic Attributes](./view/02_dynamic_attributes.md)
- [Components and Props](./view/03_components.md)
- [Iteration](./view/04_iteration.md)
- [Iterating over More Complex Data](./view/04b_iteration.md)
- [Forms and Inputs](./view/05_forms.md)
- [Control Flow](./view/06_control_flow.md)
- [Error Handling](./view/07_errors.md)
- [Parent-Child Communication](./view/08_parent_child.md)
- [Passing Children to Components](./view/09_component_children.md)
- [No Macros: The View Builder Syntax](./view/builder.md)
- [Reactivity](./reactivity/README.md)
- [Working with Signals](./reactivity/working_with_signals.md)
- [Responding to Changes with `create_effect`](./reactivity/14_create_effect.md)
- [Interlude: Reactivity and Functions](./reactivity/interlude_functions.md)
- [Interlude: Reactivity and Functions](./interlude_functions.md)
- [Testing](./testing.md)
- [Async](./async/README.md)
- [Loading Data with Resources](./async/10_resources.md)
@@ -25,6 +20,7 @@
- [Transition](./async/12_transition.md)
- [Actions](./async/13_actions.md)
- [Interlude: Projecting Children](./interlude_projecting_children.md)
- [Responding to Changes with `create_effect`](./14_create_effect.md)
- [Global State Management](./15_global_state.md)
- [Router](./router/README.md)
- [Defining `<Routes/>`](./router/16_routes.md)
@@ -33,7 +29,7 @@
- [`<A/>`](./router/19_a.md)
- [`<Form/>`](./router/20_form.md)
- [Interlude: Styling](./interlude_styling.md)
- [Metadata](./metadata.md)
- [Metadata]()
- [Server Side Rendering](./ssr/README.md)
- [`cargo-leptos`](./ssr/21_cargo_leptos.md)
- [The Life of a Page Load](./ssr/22_life_cycle.md)
@@ -41,12 +37,16 @@
- [Hydration Bugs](./ssr/24_hydration_bugs.md)
- [Working with the Server](./server/README.md)
- [Server Functions](./server/25_server_functions.md)
- [Extractors](./server/26_extractors.md)
- [Responses and Redirects](./server/27_response.md)
- [Progressive Enhancement and Graceful Degradation](./progressive_enhancement/README.md)
- [`<ActionForm/>`s](./progressive_enhancement/action_form.md)
- [Deployment](./deployment.md)
- [Guide: Islands](./islands.md)
- [Appendix: How Does the Reactive System Work?](./appendix_reactive_graph.md)
- [Request/Response]()
- [Extractors]()
- [Axum]()
- [Actix]()
- [Headers]()
- [Cookies]()
- [Building Full-Stack Apps]()
- [Actions]()
- [Forms]()
- [`<ActionForm/>`s]()
- [Turning off WebAssembly: Progressive Enhancement and Graceful Degradation]()
- [Advanced Reactivity]()
- [Appendix: Optimizing WASM Binary Size](./appendix_binary_size.md)
- [Appendix: Some Small DX Improvements](./appendix_dx.md)

View File

@@ -41,20 +41,6 @@ build-std = ["std", "panic_abort", "core", "alloc"]
build-std-features = ["panic_immediate_abort"]
```
Note that if you're using this with SSR too, the same Cargo profile will be applied. You'll need to explicitly specify your target:
```toml
[build]
target = "x86_64-unknown-linux-gnu" # or whatever
```
Also note that in some cases, the cfg feature `has_std` will not be set, which may cause build errors with some dependencies which check for `has_std`. You may fix any build errors due to this by adding:
```toml
[build]
rustflags = ["--cfg=has_std"]
```
And you'll need to add `panic = "abort"` to `[profile.release]` in `Cargo.toml`. Note that this applies the same `build-std` and panic settings to your server binary, which may not be desirable. Some further exploration is probably needed here.
5. One of the sources of binary size in WASM binaries can be `serde` serialization/deserialization code. Leptos uses `serde` by default to serialize and deserialize resources created with `create_resource`. You might try experimenting with the `miniserde` and `serde-lite` features, which allow you to use those crates for serialization and deserialization instead; each only implements a subset of `serde`s functionality, but typically optimizes for size over speed.
## Things to Avoid

View File

@@ -1,60 +0,0 @@
# A Running List of Small Developer Experience Improvements
## Autocompletion inside `#[component]` and `#[server]`
Because of the nature of macros (they can expand from anything to anything, but only if the input is exactly correct at that instant) it can be hard for rust-analyzer to do proper autocompletion and other support.
But you can tell rust-analyzer to ignore certain proc macros. For `#[component]` and `#[server]` especially, which annotate function bodies but don't actually transform anything inside the body of your function, this can be really helpful.
Note that this means that rust-analyzer doesn't know about your component props, which may generate its own set of errors or warnings in the IDE.
VSCode `settings.json`:
```json
"rust-analyzer.procMacro.ignored": {
"leptos_macro": [
"server",
"component"
],
}
```
neovim with lspconfig:
```lua
require('lspconfig').rust_analyzer.setup {
-- Other Configs ...
settings = {
["rust-analyzer"] = {
-- Other Settings ...
procMacro = {
ignored = {
leptos_macro = {
"server",
"component",
},
},
},
},
}
}
```
Helix, in `.helix/languages.toml`:
```toml
[[language]]
name = "rust"
config = { procMacro = {ignored = {leptos_macro = ["component"]}}}
```
```admonish info
The Jetbrains `intellij-rust` plugin (RustRover as well) currently does not support dynamic config for macro exclusion.
However, the project currently maintains a hardcoded list of excluded macros.
As soon as [this open PR](https://github.com/intellij-rust/intellij-rust/pull/10873) is merged, the `component` and
`server` macro will be excluded automatically without additional configuration needed.
Update (2023/10/02):
The `intellij-rust` plugin got deprecated in favor of RustRover at the same time the PR was opened, but an official
support request was made to integrate the contents of this PR.
```

View File

@@ -1,243 +0,0 @@
# Appendix: How does the Reactive System Work?
You dont need to know very much about how the reactive system actually works in order to use the library successfully. But its always useful to understand whats going on behind the scenes once you start working with the framework at an advanced level.
The reactive primitives you use are divided into three sets:
- **Signals** (`ReadSignal`/`WriteSignal`, `RwSignal`, `Resource`, `Trigger`) Values you can actively change to trigger reactive updates.
- **Computations** (`Memo`s) Values that depend on signals (or other computations) and derive a new reactive value through some pure computation.
- **Effects** Observers that listen to changes in some signals or computations and run a function, causing some side effect.
Derived signals are a kind of non-primitve computation: as plain closures, they simply allow you to refactor some repeated signal-based computation into a reusable function that can be called in multiple places, but they are not represented in the reactive system itself.
All the other primitives actually exist in the reactive system as nodes in a reactive graph.
Most of the work of the reactive system consists of propagating changes from signals to effects, possibly through some intervening memos.
The assumption of the reactive system is that effects (like rendering to the DOM or making a network request) are orders of magnitude more expensive than things like updating a Rust data structure inside your app.
So the **primary goal** of the reactive system is to **run effects as infrequently as possible**.
Leptos does this through the construction of a reactive graph.
> Leptoss current reactive system is based heavily on the [Reactively](https://github.com/modderme123/reactively) library for JavaScript. You can read Milos article “[Super-Charging Fine-Grained Reactivity](https://dev.to/modderme123/super-charging-fine-grained-reactive-performance-47ph)” for an excellent account of its algorithm, as well as fine-grained reactivity in general—including some beautiful diagrams!
## The Reactive Graph
Signals, memos, and effects all share three characteristics:
- **Value** They have a current value: either the signals value, or (for memos and effects) the value returned by the previous run, if any.
- **Sources** Any other reactive primitives they depend on. (For signals, this is an empty set.)
- **Subscribers** Any other reactive primitives that depend on them. (For effects, this is an empty set.)
In reality then, signals, memos, and effects are just conventional names for one generic concept of a “node” in a reactive graph. Signals are always “root nodes,” with no sources/parents. Effects are always “leaf nodes,” with no subscribers. Memos typically have both sources and subscribers.
### Simple Dependencies
So imagine the following code:
```rust
// A
let (name, set_name) = create_signal("Alice");
// B
let name_upper = create_memo(move |_| name.with(|n| n.to_uppercase()));
// C
create_effect(move |_| {
log!("{}", name_upper());
});
set_name("Bob");
```
You can easily imagine the reactive graph here: `name` is the only signal/origin node, the `create_effect` is the only effect/terminal node, and theres one intervening memo.
```
A (name)
|
B (name_upper)
|
C (the effect)
```
### Splitting Branches
Lets make it a little more complex.
```rust
// A
let (name, set_name) = create_signal("Alice");
// B
let name_upper = create_memo(move |_| name.with(|n| n.to_uppercase()));
// C
let name_len = create_memo(move |_| name.len());
// D
create_effect(move |_| {
log!("len = {}", name_len());
});
// E
create_effect(move |_| {
log!("name = {}", name_upper());
});
```
This is also pretty straightforward: a signal source signal (`name`/`A`) divides into two parallel tracks: `name_upper`/`B` and `name_len`/`C`, each of which has an effect that depends on it.
```
__A__
| |
B C
| |
D E
```
Now lets update the signal.
```rust
set_name("Bob");
```
We immediately log
```
len = 3
name = BOB
```
Lets do it again.
```rust
set_name("Tim");
```
The log should shows
```
name = TIM
```
`len = 3` does not log again.
Remember: the goal of the reactive system is to run effects as infrequently as possible. Changing `name` from `"Bob"` to `"Tim"` will cause each of the memos to re-run. But they will only notify their subscribers if their value has actually changed. `"BOB"` and `"TIM"` are different, so that effect runs again. But both names have the length `3`, so they do not run again.
### Reuniting Branches
One more example, of whats sometimes called **the diamond problem**.
```rust
// A
let (name, set_name) = create_signal("Alice");
// B
let name_upper = create_memo(move |_| name.with(|n| n.to_uppercase()));
// C
let name_len = create_memo(move |_| name.len());
// D
create_effect(move |_| {
log!("{} is {} characters long", name_upper(), name_len());
});
```
What does the graph look like for this?
```
__A__
| |
B C
| |
|__D__|
```
You can see why it's called the “diamond problem.” If Id connected the nodes with straight lines instead of bad ASCII art, it would form a diamond: two memos, each of which depend on a signal, which feed into the same effect.
A naive, push-based reactive implementation would cause this effect to run twice, which would be bad. (Remember, our goal is to run effects as infrequently as we can.) For example, you could implement a reactive system such that signals and memos immediately propagate their changes all the way down the graph, through each dependency, essentially traversing the graph depth-first. In other words, updating `A` would notify `B`, which would notify `D`; then `A` would notify `C`, which would notify `D` again. This is both inefficient (`D` runs twice) and glitchy (`D` actually runs with the incorrect value for the second memo during its first run.)
## Solving the Diamond Problem
Any reactive implementation worth its salt is dedicated to solving this issue. There are a number of different approaches (again, [see Milos article](https://dev.to/modderme123/super-charging-fine-grained-reactive-performance-47ph) for an excellent overview).
Heres how ours works, in brief.
A reactive node is always in one of three states:
- `Clean`: it is known not to have changed
- `Check`: it is possible it has changed
- `Dirty`: it has definitely changed
Updating a signal `Dirty` marks that signal `Dirty`, and marks all its descendants `Check`, recursively. Any of its descendants that are effects are added to a queue to be re-run.
```
____A (DIRTY)___
| |
B (CHECK) C (CHECK)
| |
|____D (CHECK)__|
```
Now those effects are run. (All of the effects will be marked `Check` at this point.) Before re-running its computation, the effect checks its parents to see if they are dirty. So
- So `D` goes to `B` and checks if it is `Dirty`.
- But `B` is also marked `Check`. So `B` does the same thing:
- `B` goes to `A`, and finds that it is `Dirty`.
- This means `B` needs to re-run, because one of its sources has changed.
- `B` re-runs, generating a new value, and marks itself `Clean`
- Because `B` is a memo, it then checks its prior value against the new value.
- If they are the same, `B` returns "no change." Otherwise, it returns "yes, I changed."
- If `B` returned “yes, I changed,” `D` knows that it definitely needs to run and re-runs immediately before checking any other sources.
- If `B` returned “no, I didnt change,” `D` continues on to check `C` (see process above for `B`.)
- If neither `B` nor `C` has changed, the effect does not need to re-run.
- If either `B` or `C` did change, the effect now re-runs.
Because the effect is only marked `Check` once and only queued once, it only runs once.
If the naive version was a “push-based” reactive system, simply pushing reactive changes all the way down the graph and therefore running the effect twice, this version could be called “push-pull.” It pushes the `Check` status all the way down the graph, but then “pulls” its way back up. In fact, for large graphs it may end up bouncing back up and down and left and right on the graph as it tries to determine exactly which nodes need to re-run.
**Note this important trade-off**: Push-based reactivity propagates signal changes more quickly, at the expense of over-re-running memos and effects. Remember: the reactive system is designed to minimize how often you re-run effects, on the (accurate) assumption that side effects are orders of magnitude more expensive than this kind of cache-friendly graph traversal happening entirely inside the librarys Rust code. The measurement of a good reactive system is not how quickly it propagates changes, but how quickly it propagates changes _without over-notifying_.
## Memos vs. Signals
Note that signals always notify their children; i.e., a signal is always marked `Dirty` when it updates, even if its new value is the same as the old value. Otherwise, wed have to require `PartialEq` on signals, and this is actually quite an expensive check on some types. (For example, add an unnecessary equality check to something like `some_vec_signal.update(|n| n.pop())` when its clear that it has in fact changed.)
Memos, on the other hand, check whether they change before notifying their children. They only run their calculation once, no matter how many times you `.get()` the result, but they run whenever their signal sources change. This means that if the memos computation is _very_ expensive, you may actually want to memoize its inputs as well, so that the memo only re-calculates when it is sure its inputs have changed.
## Memos vs. Derived Signals
All of this is cool, and memos are pretty great. But most actual applications have reactive graphs that are quite shallow and quite wide: you might have 100 source signals and 500 effects, but no memos or, in rare case, three or four memos between the signal and the effect. Memos are extremely good at what they do: limiting how often they notify their subscribers that they have changed. But as this description of the reactive system should show, they come with overhead in two forms:
1. A `PartialEq` check, which may or may not be expensive.
2. Added memory cost of storing another node in the reactive system.
3. Added computational cost of reactive graph traversal.
In cases in which the computation itself is cheaper than this reactive work, you should avoid “over-wrapping” with memos and simply use derived signals. Heres a great example in which you should never use a memo:
```rust
let (a, set_a) = create_signal(1);
// none of these make sense as memos
let b = move || a() + 2;
let c = move || b() % 2 == 0;
let d = move || if c() { "even" } else { "odd" };
set_a(2);
set_a(3);
set_a(5);
```
Even though memoizing would technically save an extra calculation of `d` between setting `a` to `3` and `5`, these calculations are themselves cheaper than the reactive algorithm.
At the very most, you might consider memoizing the final node before running some expensive side effect:
```rust
let text = create_memo(move |_| {
d()
});
create_effect(move |_| {
engrave_text_into_bar_of_gold(&text());
});
```

View File

@@ -2,7 +2,7 @@
A [Resource](https://docs.rs/leptos/latest/leptos/struct.Resource.html) is a reactive data structure that reflects the current state of an asynchronous task, allowing you to integrate asynchronous `Future`s into the synchronous reactive system. Rather than waiting for its data to load with `.await`, you transform the `Future` into a signal that returns `Some(T)` if it has resolved, and `None` if its still pending.
You do this by using the [`create_resource`](https://docs.rs/leptos/latest/leptos/fn.create_resource.html) function. This takes two arguments:
You do this by using the [`create_resource`](https://docs.rs/leptos/latest/leptos/fn.create_resource.html) function. This takes two arguments (other than the ubiquitous `cx`):
1. a source signal, which will generate a new `Future` whenever it changes
2. a fetcher function, which takes the data from that signal and returns a `Future`
@@ -11,14 +11,14 @@ Heres an example
```rust
// our source signal: some synchronous, local state
let (count, set_count) = create_signal(0);
let (count, set_count) = create_signal(cx, 0);
// our resource
let async_data = create_resource(
let async_data = create_resource(cx,
count,
// every time `count` changes, this will run
|value| async move {
logging::log!("loading data from API");
log!("loading data from API");
load_data(value).await
},
);
@@ -27,110 +27,29 @@ let async_data = create_resource(
To create a resource that simply runs once, you can pass a non-reactive, empty source signal:
```rust
let once = create_resource(|| (), |_| async move { load_data().await });
let once = create_resource(cx, || (), |_| async move { load_data().await });
```
To access the value you can use `.get()` or `.with(|data| /* */)`. These work just like `.get()` and `.with()` on a signal—`get` clones the value and returns it, `with` applies a closure to it—but for any `Resource<_, T>`, they always return `Option<T>`, not `T`: because its always possible that your resource is still loading.
To access the value you can use `.read(cx)` or `.with(cx, |data| /* */)`. These work just like `.get()` and `.with()` on a signal—`read` clones the value and returns it, `with` applies a closure to it—but with two differences
1. For any `Resource<_, T>`, they always return `Option<T>`, not `T`: because its always possible that your resource is still loading.
2. They take a `Scope` argument. Youll see why in the next chapter, on `<Suspense/>`.
So, you can show the current state of a resource in your view:
```rust
let once = create_resource(|| (), |_| async move { load_data().await });
view! {
let once = create_resource(cx, || (), |_| async move { load_data().await });
view! { cx,
<h1>"My Data"</h1>
{move || match once.get() {
None => view! { <p>"Loading..."</p> }.into_view(),
Some(data) => view! { <ShowData data/> }.into_view()
{move || match once.read(cx) {
None => view! { cx, <p>"Loading..."</p> }.into_view(cx),
Some(data) => view! { cx, <ShowData data/> }.into_view(cx)
}}
}
```
Resources also provide a `refetch()` method that allows you to manually reload the data (for example, in response to a button click) and a `loading()` method that returns a `ReadSignal<bool>` indicating whether the resource is currently loading or not.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/10-resources-0-5-9jq86q?file=%2Fsrc%2Fmain.rs%3A1%2C2)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/10-async-resources-4z0qt3?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/10-resources-0-5-9jq86q?file=%2Fsrc%2Fmain.rs%3A1%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use gloo_timers::future::TimeoutFuture;
use leptos::*;
// Here we define an async function
// This could be anything: a network request, database read, etc.
// Here, we just multiply a number by 10
async fn load_data(value: i32) -> i32 {
// fake a one-second delay
TimeoutFuture::new(1_000).await;
value * 10
}
#[component]
fn App() -> impl IntoView {
// this count is our synchronous, local state
let (count, set_count) = create_signal(0);
// create_resource takes two arguments after its scope
let async_data = create_resource(
// the first is the "source signal"
count,
// the second is the loader
// it takes the source signal's value as its argument
// and does some async work
|value| async move { load_data(value).await },
);
// whenever the source signal changes, the loader reloads
// you can also create resources that only load once
// just return the unit type () from the source signal
// that doesn't depend on anything: we just load it once
let stable = create_resource(|| (), |_| async move { load_data(1).await });
// we can access the resource values with .get()
// this will reactively return None before the Future has resolved
// and update to Some(T) when it has resolved
let async_result = move || {
async_data
.get()
.map(|value| format!("Server returned {value:?}"))
// This loading state will only show before the first load
.unwrap_or_else(|| "Loading...".into())
};
// the resource's loading() method gives us a
// signal to indicate whether it's currently loading
let loading = async_data.loading();
let is_loading = move || if loading() { "Loading..." } else { "Idle." };
view! {
<button
on:click=move |_| {
set_count.update(|n| *n += 1);
}
>
"Click me"
</button>
<p>
<code>"stable"</code>": " {move || stable.get()}
</p>
<p>
<code>"count"</code>": " {count}
</p>
<p>
<code>"async_value"</code>": "
{async_result}
<br/>
{is_loading}
</p>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/10-async-resources-4z0qt3?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -3,14 +3,14 @@
In the previous chapter, we showed how you can create a simple loading screen to show some fallback while a resource is loading.
```rust
let (count, set_count) = create_signal(0);
let once = create_resource(count, |count| async move { load_a(count).await });
let (count, set_count) = create_signal(cx, 0);
let a = create_resource(cx, count, |count| async move { load_a(count).await });
view! {
view! { cx,
<h1>"My Data"</h1>
{move || match once.get() {
None => view! { <p>"Loading..."</p> }.into_view(),
Some(data) => view! { <ShowData data/> }.into_view()
{move || match once.read(cx) {
None => view! { cx, <p>"Loading..."</p> }.into_view(cx),
Some(data) => view! { cx, <ShowData data/> }.into_view(cx)
}}
}
```
@@ -18,19 +18,19 @@ view! {
But what if we have two resources, and want to wait for both of them?
```rust
let (count, set_count) = create_signal(0);
let (count2, set_count2) = create_signal(0);
let a = create_resource(count, |count| async move { load_a(count).await });
let b = create_resource(count2, |count| async move { load_b(count).await });
let (count, set_count) = create_signal(cx, 0);
let (count2, set_count2) = create_signal(cx, 0);
let a = create_resource(cx, count, |count| async move { load_a(count).await });
let b = create_resource(cx, count2, |count| async move { load_b(count).await });
view! {
view! { cx,
<h1>"My Data"</h1>
{move || match (a.get(), b.get()) {
(Some(a), Some(b)) => view! {
{move || match (a.read(cx), b.read(cx)) {
(Some(a), Some(b)) => view! { cx,
<ShowA a/>
<ShowA b/>
}.into_view(),
_ => view! { <p>"Loading..."</p> }.into_view()
}.into_view(cx),
_ => view! { cx, <p>"Loading..."</p> }.into_view(cx)
}}
}
```
@@ -40,26 +40,26 @@ Thats not _so_ bad, but its kind of annoying. What if we could invert the
The [`<Suspense/>`](https://docs.rs/leptos/latest/leptos/fn.Suspense.html) component lets us do exactly that. You give it a `fallback` prop and children, one or more of which usually involves reading from a resource. Reading from a resource “under” a `<Suspense/>` (i.e., in one of its children) registers that resource with the `<Suspense/>`. If its still waiting for resources to load, it shows the `fallback`. When theyve all loaded, it shows the children.
```rust
let (count, set_count) = create_signal(0);
let (count2, set_count2) = create_signal(0);
let a = create_resource(count, |count| async move { load_a(count).await });
let b = create_resource(count2, |count| async move { load_b(count).await });
let (count, set_count) = create_signal(cx, 0);
let (count2, set_count2) = create_signal(cx, 0);
let a = create_resource(cx, count, |count| async move { load_a(count).await });
let b = create_resource(cx, count2, |count| async move { load_b(count).await });
view! {
view! { cx,
<h1>"My Data"</h1>
<Suspense
fallback=move || view! { <p>"Loading..."</p> }
fallback=move || view! { cx, <p>"Loading..."</p> }
>
<h2>"My Data"</h2>
<h3>"A"</h3>
{move || {
a.get()
.map(|a| view! { <ShowA a/> })
a.read(cx)
.map(|a| view! { cx, <ShowA a/> })
}}
<h3>"B"</h3>
{move || {
b.get()
.map(|b| view! { <ShowB b/> })
b.read(cx)
.map(|b| view! { cx, <ShowB b/> })
}}
</Suspense>
}
@@ -69,88 +69,6 @@ Every time one of the resources is reloading, the `"Loading..."` fallback will s
This inversion of the flow of control makes it easier to add or remove individual resources, as you dont need to handle the matching yourself. It also unlocks some massive performance improvements during server-side rendering, which well talk about during a later chapter.
## `<Await/>`
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/11-suspense-907niv?file=%2Fsrc%2Fmain.rs)
In youre simply trying to wait for some `Future` to resolve before rendering, you may find the `<Await/>` component helpful in reducing boilerplate. `<Await/>` essentially combines a resource with the source argument `|| ()` with a `<Suspense/>` with no fallback.
In other words:
1. It only polls the `Future` once, and does not respond to any reactive changes.
2. It does not render anything until the `Future` resolves.
3. After the `Future` resolves, its binds its data to whatever variable name you choose and then renders its children with that variable in scope.
```rust
async fn fetch_monkeys(monkey: i32) -> i32 {
// maybe this didn't need to be async
monkey * 2
}
view! {
<Await
// `future` provides the `Future` to be resolved
future=|| fetch_monkeys(3)
// the data is bound to whatever variable name you provide
let:data
>
// you receive the data by reference and can use it in your view here
<p>{*data} " little monkeys, jumping on the bed."</p>
</Await>
}
```
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/11-suspense-0-5-qzpgqs?file=%2Fsrc%2Fmain.rs%3A1%2C1)
<iframe src="https://codesandbox.io/p/sandbox/11-suspense-0-5-qzpgqs?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use gloo_timers::future::TimeoutFuture;
use leptos::*;
async fn important_api_call(name: String) -> String {
TimeoutFuture::new(1_000).await;
name.to_ascii_uppercase()
}
#[component]
fn App() -> impl IntoView {
let (name, set_name) = create_signal("Bill".to_string());
// this will reload every time `name` changes
let async_data = create_resource(
name,
|name| async move { important_api_call(name).await },
);
view! {
<input
on:input=move |ev| {
set_name(event_target_value(&ev));
}
prop:value=name
/>
<p><code>"name:"</code> {name}</p>
<Suspense
// the fallback will show whenever a resource
// read "under" the suspense is loading
fallback=move || view! { <p>"Loading..."</p> }
>
// the children will be rendered once initially,
// and then whenever any resources has been resolved
<p>
"Your shouting name is "
{move || async_data.get()}
</p>
</Suspense>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/11-suspense-907niv?file=%2Fsrc%2Fmain.rs" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -6,78 +6,6 @@ Youll notice in the `<Suspense/>` example that if you keep reloading the data
This example shows how you can create a simple tabbed contact list with `<Transition/>`. When you select a new tab, it continues showing the current contact until the new data loads. This can be a much better user experience than constantly falling back to a loading message.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/12-transition-0-5-2jg5lz?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/12-transition-sn38sd?selection=%5B%7B%22endColumn%22%3A15%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A15%2C%22startLineNumber%22%3A2%7D%5D&file=%2Fsrc%2Fmain.rs)
<iframe src="https://codesandbox.io/p/sandbox/12-transition-0-5-2jg5lz?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use gloo_timers::future::TimeoutFuture;
use leptos::*;
async fn important_api_call(id: usize) -> String {
TimeoutFuture::new(1_000).await;
match id {
0 => "Alice",
1 => "Bob",
2 => "Carol",
_ => "User not found",
}
.to_string()
}
#[component]
fn App() -> impl IntoView {
let (tab, set_tab) = create_signal(0);
// this will reload every time `tab` changes
let user_data = create_resource(tab, |tab| async move { important_api_call(tab).await });
view! {
<div class="buttons">
<button
on:click=move |_| set_tab(0)
class:selected=move || tab() == 0
>
"Tab A"
</button>
<button
on:click=move |_| set_tab(1)
class:selected=move || tab() == 1
>
"Tab B"
</button>
<button
on:click=move |_| set_tab(2)
class:selected=move || tab() == 2
>
"Tab C"
</button>
{move || if user_data.loading().get() {
"Loading..."
} else {
""
}}
</div>
<Transition
// the fallback will show initially
// on subsequent reloads, the current child will
// continue showing
fallback=move || view! { <p>"Loading..."</p> }
>
<p>
{move || user_data.read()}
</p>
</Transition>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/12-transition-sn38sd?selection=%5B%7B%22endColumn%22%3A15%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A15%2C%22startLineNumber%22%3A2%7D%5D&file=%2Fsrc%2Fmain.rs" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -11,27 +11,27 @@ Actions and resources seem similar, but they represent fundamentally different t
Say we have some `async` function we want to run.
```rust
async fn add_todo_request(new_title: &str) -> Uuid {
async fn add_todo(new_title: &str) -> Uuid {
/* do some stuff on the server to add a new todo */
}
```
`create_action` takes an `async` function that takes a reference to a single argument, which you could think of as its “input type.”
`create_action` takes a reactive `Scope` and an `async` function that takes a reference to a single argument, which you could think of as its “input type.”
> The input is always a single type. If you want to pass in multiple arguments, you can do it with a struct or tuple.
>
> ```rust
> // if there's a single argument, just use that
> let action1 = create_action(|input: &String| {
> let action1 = create_action(cx, |input: &String| {
> let input = input.clone();
> async move { todo!() }
> });
>
> // if there are no arguments, use the unit type `()`
> let action2 = create_action(|input: &()| async { todo!() });
> let action2 = create_action(cx, |input: &()| async { todo!() });
>
> // if there are multiple arguments, use a tuple
> let action3 = create_action(
> let action3 = create_action(cx,
> |input: &(usize, String)| async { todo!() }
> );
> ```
@@ -41,16 +41,16 @@ async fn add_todo_request(new_title: &str) -> Uuid {
So in this case, all we need to do to create an action is
```rust
let add_todo_action = create_action(|input: &String| {
let add_todo = create_action(cx, |input: &String| {
let input = input.to_owned();
async move { add_todo_request(&input).await }
async move { add_todo(&input).await }
});
```
Rather than calling `add_todo_action` directly, well call it with `.dispatch()`, as in
Rather than calling `add_todo` directly, well call it with `.dispatch()`, as in
```rust
add_todo_action.dispatch("Some value".to_string());
add_todo.dispatch("Some value".to_string());
```
You can do this from an event listener, a timeout, or anywhere; because `.dispatch()` isnt an `async` function, it can be called from a synchronous context.
@@ -58,22 +58,22 @@ You can do this from an event listener, a timeout, or anywhere; because `.dispat
Actions provide access to a few signals that synchronize between the asynchronous action youre calling and the synchronous reactive system:
```rust
let submitted = add_todo_action.input(); // RwSignal<Option<String>>
let pending = add_todo_action.pending(); // ReadSignal<bool>
let todo_id = add_todo_action.value(); // RwSignal<Option<Uuid>>
let submitted = add_todo.input(); // RwSignal<Option<String>>
let pending = add_todo.pending(); // ReadSignal<bool>
let todo_id = add_todo.value(); // RwSignal<Option<Uuid>>
```
This makes it easy to track the current state of your request, show a loading indicator, or do “optimistic UI” based on the assumption that the submission will succeed.
```rust
let input_ref = create_node_ref::<Input>();
let input_ref = create_node_ref::<Input>(cx);
view! {
view! { cx,
<form
on:submit=move |ev| {
ev.prevent_default(); // don't reload the page...
let input = input_ref.get().expect("input to exist");
add_todo_action.dispatch(input.value());
add_todo.dispatch(input.value());
}
>
<label>
@@ -91,86 +91,6 @@ view! {
Now, theres a chance this all seems a little over-complicated, or maybe too restricted. I wanted to include actions here, alongside resources, as the missing piece of the puzzle. In a real Leptos app, youll actually most often use actions alongside server functions, [`create_server_action`](https://docs.rs/leptos/latest/leptos/fn.create_server_action.html), and the [`<ActionForm/>`](https://docs.rs/leptos_router/latest/leptos_router/fn.ActionForm.html) component to create really powerful progressively-enhanced forms. So if this primitive seems useless to you... Dont worry! Maybe it will make sense later. (Or check out our [`todo_app_sqlite`](https://github.com/leptos-rs/leptos/blob/main/examples/todo_app_sqlite/src/todo.rs) example now.)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/13-actions-0-5-8xk35v?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/10-async-resources-forked-hgpfp0?selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A4%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A4%7D%5D&file=%2Fsrc%2Fmain.rs)
<iframe src="https://codesandbox.io/p/sandbox/13-actions-0-5-8xk35v?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use gloo_timers::future::TimeoutFuture;
use leptos::{html::Input, *};
use uuid::Uuid;
// Here we define an async function
// This could be anything: a network request, database read, etc.
// Think of it as a mutation: some imperative async action you run,
// whereas a resource would be some async data you load
async fn add_todo(text: &str) -> Uuid {
_ = text;
// fake a one-second delay
TimeoutFuture::new(1_000).await;
// pretend this is a post ID or something
Uuid::new_v4()
}
#[component]
fn App() -> impl IntoView {
// an action takes an async function with single argument
// it can be a simple type, a struct, or ()
let add_todo = create_action(|input: &String| {
// the input is a reference, but we need the Future to own it
// this is important: we need to clone and move into the Future
// so it has a 'static lifetime
let input = input.to_owned();
async move { add_todo(&input).await }
});
// actions provide a bunch of synchronous, reactive variables
// that tell us different things about the state of the action
let submitted = add_todo.input();
let pending = add_todo.pending();
let todo_id = add_todo.value();
let input_ref = create_node_ref::<Input>();
view! {
<form
on:submit=move |ev| {
ev.prevent_default(); // don't reload the page...
let input = input_ref.get().expect("input to exist");
add_todo.dispatch(input.value());
}
>
<label>
"What do you need to do?"
<input type="text"
node_ref=input_ref
/>
</label>
<button type="submit">"Add Todo"</button>
</form>
<p>{move || pending().then(|| "Loading...")}</p>
<p>
"Submitted: "
<code>{move || format!("{:#?}", submitted())}</code>
</p>
<p>
"Pending: "
<code>{move || format!("{:#?}", pending())}</code>
</p>
<p>
"Todo ID: "
<code>{move || format!("{:#?}", todo_id())}</code>
</p>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/10-async-resources-forked-hgpfp0?selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A4%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A4%7D%5D&file=%2Fsrc%2Fmain.rs" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -1,74 +0,0 @@
# Deployment
There are as many ways to deploy a web application as there are developers, let alone applications. But there are a couple useful tips to keep in mind when deploying an app.
## General Advice
1. Remember: Always deploy Rust apps built in `--release` mode, not debug mode. This has a huge effect on both performance and binary size.
2. Test locally in release mode as well. The framework applies certain optimizations in release mode that it does not apply in debug mode, so its possible for bugs to surface at this point. (If your app behaves differently or you do encounter a bug, its likely a framework-level bug and you should open a GitHub issue with a reproduction.)
> We asked users to submit their deployment setups to help with this chapter. Ill quote from them below, but you can read the full thread [here](https://github.com/leptos-rs/leptos/issues/1152).
## Deploying a Client-Side-Rendered App
If youve been building an app that only uses client-side rendering, working with Trunk as a dev server and build tool, the process is quite easy.
```bash
trunk build --release
```
`trunk build` will create a number of build artifacts in a `dist/` directory. Publishing `dist` somewhere online should be all you need to deploy your app. This should work very similarly to deploying any JavaScript application.
> Read more: [Deploying to Vercel with GitHub Actions](https://github.com/leptos-rs/leptos/issues/1152#issuecomment-1577861900).
## Deploying a Full-Stack App
The most popular way for people to deploy full-stack apps built with `cargo-leptos` is to use a cloud hosting service that supports deployment via a Docker build. Heres a sample `Dockerfile`, which is based on the one we use to deploy the Leptos website.
```dockerfile
# Get started with a build env with Rust nightly
FROM rustlang/rust:nightly-bullseye as builder
# If youre using stable, use this instead
# FROM rust:1.70-bullseye as builder
# Install cargo-binstall, which makes it easier to install other
# cargo extensions like cargo-leptos
RUN wget https://github.com/cargo-bins/cargo-binstall/releases/latest/download/cargo-binstall-x86_64-unknown-linux-musl.tgz
RUN tar -xvf cargo-binstall-x86_64-unknown-linux-musl.tgz
RUN cp cargo-binstall /usr/local/cargo/bin
# Install cargo-leptos
RUN cargo binstall cargo-leptos -y
# Add the WASM target
RUN rustup target add wasm32-unknown-unknown
# Make an /app dir, which everything will eventually live in
RUN mkdir -p /app
WORKDIR /app
COPY . .
# Build the app
RUN cargo leptos build --release -vv
FROM rustlang/rust:nightly-bullseye as runner
# Copy the server binary to the /app directory
COPY --from=builder /app/target/release/leptos-start /app/
# /target/site contains our JS/WASM/CSS, etc.
COPY --from=builder /app/target/site /app/site
# Copy Cargo.toml if its needed at runtime
COPY --from=builder /app/Cargo.toml /app/
WORKDIR /app
# Set any required env variables and
ENV RUST_LOG="info"
ENV APP_ENVIRONMENT="production"
ENV LEPTOS_SITE_ADDR="0.0.0.0:8080"
ENV LEPTOS_SITE_ROOT="site"
EXPOSE 8080
# Run the server
CMD ["/app/leptos_start"]
```
> Read more: [`gnu` and `musl` build files for Leptos apps](https://github.com/leptos-rs/leptos/issues/1152#issuecomment-1634916088).

View File

@@ -6,7 +6,7 @@ application. It sometimes looks a little silly:
```rust
// a signal holds a value, and can be updated
let (count, set_count) = create_signal(0);
let (count, set_count) = create_signal(cx, 0);
// a derived signal is a function that accesses other signals
let double_count = move || count() * 2;
@@ -19,11 +19,11 @@ let text = move || if count_is_odd() {
// an effect automatically tracks the signals it depends on
// and reruns when they change
create_effect(move |_| {
logging::log!("text = {}", text());
create_effect(cx, move |_| {
log!("text = {}", text());
});
view! {
view! { cx,
<p>{move || text().to_uppercase()}</p>
}
```
@@ -53,12 +53,12 @@ Take our typical `<SimpleCounter/>` example in its simplest form:
```rust
#[component]
pub fn SimpleCounter() -> impl IntoView {
let (value, set_value) = create_signal(0);
pub fn SimpleCounter(cx: Scope) -> impl IntoView {
let (value, set_value) = create_signal(cx, 0);
let increment = move |_| set_value.update(|value| *value += 1);
view! {
view! { cx,
<button on:click=increment>
{value}
</button>
@@ -68,7 +68,7 @@ pub fn SimpleCounter() -> impl IntoView {
The `SimpleCounter` function itself runs once. The `value` signal is created once. The framework hands off the `increment` function to the browser as an event listener. When you click the button, the browser calls `increment`, which updates `value` via `set_value`. And that updates the single text node represented in our view by `{value}`.
Closures are key to reactivity. They provide the framework with the ability to rerun the smallest possible unit of your application in response to a change.
Closures are key to reactivity. They provide the framework with the ability to rerun the smallest possible unit of your application in responsive to a change.
So remember two things:

View File

@@ -7,12 +7,12 @@ As you build components you may occasionally find yourself wanting to “project
Consider the following:
```rust
pub fn LoggedIn<F, IV>(fallback: F, children: ChildrenFn) -> impl IntoView
pub fn LoggedIn<F, IV>(cx: Scope, fallback: F, children: ChildrenFn) -> impl IntoView
where
F: Fn() -> IV + 'static,
F: Fn(Scope) -> IV + 'static,
IV: IntoView,
{
view! {
view! { cx,
<Suspense
fallback=|| ()
>
@@ -22,16 +22,16 @@ where
when=move || todo!()
fallback=fallback
>
{children()}
{children(cx)}
</Show>
</Suspense>
}
}
```
This is pretty straightforward: when the user is logged in, we want to show `children`. If the user is not logged in, we want to show `fallback`. And while were waiting to find out, we just render `()`, i.e., nothing.
This is pretty straightforward: when the user is logged in, we want to show `children`. Until if the user is not logged in, we want to show `fallback`. And while were waiting to find out, we just render `()`, i.e., nothing.
In other words, we want to pass the children of `<LoggedIn/>` _through_ the `<Suspense/>` component to become the children of the `<Show/>`. This is what I mean by “projection.”
In other words, we want to pass the children of `<WhenLoaded/>` _through_ the `<Suspense/>` component to become the children of the `<Show/>`. This is what I mean by “projection.”
This wont compile.
@@ -50,16 +50,18 @@ If you want to really understand the issue here, it may help to look at the expa
```rust
Suspense(
cx,
::leptos::component_props_builder(&Suspense)
.fallback(|| ())
.children({
// fallback and children are moved into this closure
Box::new(move || {
Box::new(move |cx| {
{
// fallback and children captured here
leptos::Fragment::lazy(|| {
vec![
(Show(
cx,
::leptos::component_props_builder(&Show)
.when(|| true)
// but fallback is moved into Show here
@@ -68,7 +70,7 @@ Suspense(
.children(children)
.build(),
)
.into_view()),
.into_view(cx)),
]
})
}
@@ -89,22 +91,22 @@ We can solve this problem by using the [`store_value`](https://docs.rs/leptos/la
In this case, its really simple:
```rust
pub fn LoggedIn<F, IV>(fallback: F, children: ChildrenFn) -> impl IntoView
pub fn LoggedIn<F, IV>(cx: Scope, fallback: F, children: ChildrenFn) -> impl IntoView
where
F: Fn() -> IV + 'static,
F: Fn(Scope) -> IV + 'static,
IV: IntoView,
{
let fallback = store_value(fallback);
let children = store_value(children);
view! {
let fallback = store_value(cx, fallback);
let children = store_value(cx, children);
view! { cx,
<Suspense
fallback=|| ()
>
<Show
when=|| todo!()
fallback=move || fallback.with_value(|fallback| fallback())
fallback=move |cx| fallback.with_value(|fallback| fallback(cx))
>
{children.with_value(|children| children())}
{children.with_value(|children| children(cx))}
</Show>
</Suspense>
}
@@ -123,9 +125,9 @@ Consider this example
```rust
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
let name = "Alice".to_string();
view! {
view! { cx,
<Outer>
<Inner>
<Inmost name=name.clone()/>
@@ -135,18 +137,18 @@ pub fn App() -> impl IntoView {
}
#[component]
pub fn Outer(ChildrenFn) -> impl IntoView {
children()
pub fn Outer(cx: Scope, children: ChildrenFn) -> impl IntoView {
children(cx)
}
#[component]
pub fn Inner(ChildrenFn) -> impl IntoView {
children()
pub fn Inner(cx: Scope, children: ChildrenFn) -> impl IntoView {
children(cx)
}
#[component]
pub fn Inmost(ng) -> impl IntoView {
view! {
pub fn Inmost(cx: Scope, name: String) -> impl IntoView {
view! { cx,
<p>{name}</p>
}
}
@@ -163,7 +165,7 @@ Its captured through multiple levels of children that need to run more than o
In this case, the `clone:` syntax comes in handy. Calling `clone:name` will clone `name` _before_ moving it into `<Inner/>`s children, which solves our ownership issue.
```rust
view! {
view! { cx,
<Outer>
<Inner clone:name>
<Inmost name=name.clone()/>

View File

@@ -14,10 +14,10 @@ This allows you to write components like this:
```rust
#[component]
fn Home() -> impl IntoView {
let (count, set_count) = create_signal(0);
fn Home(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
view! {
view! { cx,
<main class="my-0 mx-auto max-w-3xl text-center">
<h2 class="p-6 text-4xl">"Welcome to Leptos with Tailwind"</h2>
<p class="px-10 pb-10 text-left">"Tailwind will scan your Rust files for Tailwind class names and compile them into a CSS file."</p>
@@ -36,7 +36,7 @@ fn Home() -> impl IntoView {
}
```
It can be a little complicated to set up the Tailwind integration at first, but you can check out our two examples of how to use Tailwind with a [client-side-rendered `trunk` application](https://github.com/leptos-rs/leptos/tree/main/examples/tailwind_csr) or with a [server-rendered `cargo-leptos` application](https://github.com/leptos-rs/leptos/tree/main/examples/tailwind_actix). `cargo-leptos` also has some [built-in Tailwind support](https://github.com/leptos-rs/cargo-leptos#site-parameters) that you can use as an alternative to Tailwinds CLI.
It can be a little complicated to set up the Tailwind integration at first, but you can check out our two examples of how to use Tailwind with a [client-side-rendered `trunk` application](https://github.com/leptos-rs/leptos/tree/main/examples/tailwind_csr_trunk) or with a [server-rendered `cargo-leptos` application](https://github.com/leptos-rs/leptos/tree/main/examples/tailwind). `cargo-leptos` also has some [built-in Tailwind support](https://github.com/leptos-rs/cargo-leptos#site-parameters) that you can use as an alternative to Tailwinds CLI.
## Stylers: Compile-time CSS Extraction
@@ -48,9 +48,9 @@ This allows you to write components like this:
use stylers::style;
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
let styler_class = style! { "App",
##two{
#two{
color: blue;
}
div.one{
@@ -74,7 +74,7 @@ pub fn App() -> impl IntoView {
}
};
view! { class = styler_class,
view! { cx, class = styler_class,
<div class="one">
<h1 id="two">"Hello"</h1>
<h2>"World"</h2>
@@ -93,7 +93,7 @@ pub fn App() -> impl IntoView {
use styled::style;
#[component]
pub fn MyComponent() -> impl IntoView {
pub fn MyComponent(cx: Scope) -> impl IntoView {
let styles = style!(
div {
background-color: red;
@@ -101,7 +101,7 @@ pub fn MyComponent() -> impl IntoView {
}
);
styled::view! { styles,
styled::view! { cx, styles,
<div>"This text should be red with white text."</div>
}
}

View File

@@ -1,489 +0,0 @@
# Guide: Islands
Leptos 0.5 introduces the new `experimental-islands` feature. This guide will walk through the islands feature and core concepts, while implementing a demo app using the islands architecture.
## The Islands Architecture
The dominant JavaScript frontend frameworks (React, Vue, Svelte, Solid, Angular) all originated as frameworks for building client-rendered single-page apps (SPAs). The initial page load is rendered to HTML, then hydrated, and subsequent navigations are handled directly in the client. (Hence “single page”: everything happens from a single page load from the server, even if there is client-side routing later.) Each of these frameworks later added server-side rendering to improve initial load times, SEO, and user experience.
This means that by default, the entire app is interactive. It also means that the entire app has to be shipped to the client as JavaScript in order to be hydrated. Leptos has followed this same pattern.
> You can read more in the chapters on [server-side rendering](./ssr/22_life_cycle.md).
But its also possible to work in the opposite direction. Rather than taking an entirely-interactive app, rendering it to HTML on the server, and then hydrating it in the browser, you can begin with a plain HTML page and add small areas of interactivity. This is the traditional format for any website or app before the 2010s: your browser makes a series of requests to the server and returns the HTML for each new page in response. After the rise of “single-page apps” (SPA), this approach has sometimes become known as a “multi-page app” (MPA) by comparison.
The phrase “islands architecture” has emerged recently to describe the approach of beginning with a “sea” of server-rendered HTML pages, and adding “islands” of interactivity throughout the page.
> ### Additional Reading
>
> The rest of this guide will look at how to use islands with Leptos. For more background on the approach in general, check out some of the articles below:
>
> - Jason Miller, [“Islands Architecture”](https://jasonformat.com/islands-architecture/), Jason Miller
> - Ryan Carniato, [“Islands & Server Components & Resumability, Oh My!”](https://dev.to/this-is-learning/islands-server-components-resumability-oh-my-319d)
> - [“Islands Architectures”](https://www.patterns.dev/posts/islands-architecture) on patterns.dev
> - [Astro Islands](https://docs.astro.build/en/concepts/islands/)
## Activating Islands Mode
Lets start with a fresh `cargo-leptos` app:
```bash
cargo leptos new --git leptos-rs/start
```
> Im using Actix because I like it. Feel free to use Axum; there should be approximately no server-specific differences in this guide.
Im just going to run
```bash
cargo leptos build
```
in the background while I fire up my editor and keep writing.
The first thing Ill do is to add the `experimental-islands` feature in my `Cargo.toml`. I need to add this to both `leptos` and `leptos_actix`:
```toml
leptos = { version = "0.5", features = ["nightly", "experimental-islands"] }
leptos_actix = { version = "0.5", optional = true, features = [
"experimental-islands",
] }
```
Next Im going to modify the `hydrate` function exported from `src/lib.rs`. Im going to remove the line that calls `leptos::mount_to_body(App)` and replace it with
```rust
leptos::leptos_dom::HydrationCtx::stop_hydrating();
```
Each “island” we create will actually act as its own entrypoint, so our `hydrate()` function just says “okay, hydrations done now.”
Okay, now fire up your `cargo leptos watch` and go to [`http://localhost:3000`](http://localhost:3000) (or wherever).
Click the button, and...
Nothing happens!
Perfect.
## Using Islands
Nothing happens because weve just totally inverted the mental model of our app. Rather than being interactive by default and hydrating everything, the app is now plain HTML by default, and we need to opt into interactivity.
This has a big effect on WASM binary sizes: if I compile in release mode, this app is a measly 24kb of WASM (uncompressed), compared to 355kb in non-islands mode. (355kb is quite large for a “Hello, world!” Its really just all the code related to client-side routing, which isnt being used in the demo.)
When we click the button, nothing happens, because our whole page is static.
So how do we make something happen?
Lets turn the `HomePage` component into an island!
Here was the non-interactive version:
```rust
#[component]
fn HomePage() -> impl IntoView {
// Creates a reactive value to update the button
let (count, set_count) = create_signal(0);
let on_click = move |_| set_count.update(|count| *count += 1);
view! {
<h1>"Welcome to Leptos!"</h1>
<button on:click=on_click>"Click Me: " {count}</button>
}
}
```
Heres the interactive version:
```rust
#[island]
fn HomePage() -> impl IntoView {
// Creates a reactive value to update the button
let (count, set_count) = create_signal(0);
let on_click = move |_| set_count.update(|count| *count += 1);
view! {
<h1>"Welcome to Leptos!"</h1>
<button on:click=on_click>"Click Me: " {count}</button>
}
}
```
Now when I click the button, it works!
The `#[island]` macro works exactly like the `#[component]` macro, except that in islands mode, it designates this as an interactive island. If we check the binary size again, this is 166kb uncompressed in release mode; much larger than the 24kb totally static version, but much smaller than the 355kb fully-hydrated version.
If you open up the source for the page now, youll see that your `HomePage` island has been rendered as a special `<leptos-island>` HTML element which specifies which component should be used to hydrate it:
```html
<leptos-island data-component="HomePage" data-hkc="0-0-0">
<h1 data-hk="0-0-2">Welcome to Leptos!</h1>
<button data-hk="0-0-3">
Click Me:
<!-- <DynChild> -->11<!-- </DynChild> -->
</button>
</leptos-island>
```
The typical Leptos hydration keys and markers are only present inside the island, only the island is hydrated.
## Using Islands Effectively
Remember that _only_ code within an `#[island]` needs to be compiled to WASM and shipped to the browser. This means that islands should be as small and specific as possible. My `HomePage`, for example, would be better broken apart into a regular component and an island:
```rust
#[component]
fn HomePage() -> impl IntoView {
view! {
<h1>"Welcome to Leptos!"</h1>
<Counter/>
}
}
#[island]
fn Counter() -> impl IntoView {
// Creates a reactive value to update the button
let (count, set_count) = create_signal(0);
let on_click = move |_| set_count.update(|count| *count += 1);
view! {
<button on:click=on_click>"Click Me: " {count}</button>
}
}
```
Now the `<h1>` doesnt need to be included in the client bundle, or hydrated. This seems like a silly distinction now; but note that you can now add as much inert HTML content as you want to the `HomePage` itself, and the WASM binary size will remain exactly the same.
In regular hydration mode, your WASM binary size grows as a function of the size/complexity of your app. In islands mode, your WASM binary grows as a function of the amount of interactivity in your app. You can add as much non-interactive content as you want, outside islands, and it will not increase that binary size.
## Unlocking Superpowers
So, this 50% reduction in WASM binary size is nice. But really, whats the point?
The point comes when you combine two key facts:
1. Code inside `#[component]` functions now _only_ runs on the server.
2. Children and props can be passed from the server to islands, without being included in the WASM binary.
This means you can run server-only code directly in the body of a component, and pass it directly into the children. Certain tasks that take a complex blend of server functions and Suspense in fully-hydrated apps can be done inline in islands.
Were going to rely on a third fact in the rest of this demo:
3. Context can be passed between otherwise-independent islands.
So, instead of our counter demo, lets make something a little more fun: a tabbed interface that reads data from files on the server.
## Passing Server Children to Islands
One of the most powerful things about islands is that you can pass server-rendered children into an island, without the island needing to know anything about them. Islands hydrate their own content, but not children that are passed to them.
As Dan Abramov of React put it (in the very similar context of RSCs), islands arent really islands: theyre donuts. You can pass server-only content directly into the “donut hole,” as it were, allowing you to create tiny atolls of interactivity, surrounded on _both_ sides by the sea of inert server HTML.
> In the demo code included below, I added some styles to show all server content as a light-blue “sea,” and all islands as light-green “land.” Hopefully that will help picture what Im talking about!
To continue with the demo: Im going to create a `Tabs` component. Switching between tabs will require some interactivity, so of course this will be an island. Lets start simple for now:
```rust
#[island]
fn Tabs(labels: Vec<String>) -> impl IntoView {
let buttons = labels
.into_iter()
.map(|label| view! { <button>{label}</button> })
.collect_view();
view! {
<div style="display: flex; width: 100%; justify-content: space-between;">
{buttons}
</div>
}
}
```
Oops. This gives me an error
```
error[E0463]: can't find crate for `serde`
--> src/app.rs:43:1
|
43 | #[island]
| ^^^^^^^^^ can't find crate
```
Easy fix: lets `cargo add serde --features=derive`. The `#[island]` macro wants to pull in `serde` here because it needs to serialize and deserialize the `labels` prop.
Now lets update the `HomePage` to use `Tabs`.
```rust
#[component]
fn HomePage() -> impl IntoView {
// these are the files were going to read
let files = ["a.txt", "b.txt", "c.txt"];
// the tab labels will just be the file names
let labels = files.iter().copied().map(Into::into).collect();
view! {
<h1>"Welcome to Leptos!"</h1>
<p>"Click any of the tabs below to read a recipe."</p>
<Tabs labels/>
}
}
```
If you take a look in the DOM inspector, youll see the island is now something like
```html
<leptos-island
data-component="Tabs"
data-hkc="0-0-0"
data-props='{"labels":["a.txt","b.txt","c.txt"]}'
></leptos-island>
```
Our `labels` prop is getting serialized to JSON and stored in an HTML attribute so it can be used to hydrate the island.
Now lets add some tabs. For the moment, a `Tab` island will be really simple:
```rust
#[island]
fn Tab(index: usize, children: Children) -> impl IntoView {
view! {
<div>{children()}</div>
}
}
```
Each tab, for now will just be a `<div>` wrapping its children.
Our `Tabs` component will also get some children: for now, lets just show them all.
```rust
#[island]
fn Tabs(labels: Vec<String>, children: Children) -> impl IntoView {
let buttons = labels
.into_iter()
.map(|label| view! { <button>{label}</button> })
.collect_view();
view! {
<div style="display: flex; width: 100%; justify-content: space-around;">
{buttons}
</div>
{children()}
}
}
```
Okay, now lets go back into the `HomePage`. Were going to create the list of tabs to put into our tab box.
```rust
#[component]
fn HomePage() -> impl IntoView {
let files = ["a.txt", "b.txt", "c.txt"];
let labels = files.iter().copied().map(Into::into).collect();
let tabs = move || {
files
.into_iter()
.enumerate()
.map(|(index, filename)| {
let content = std::fs::read_to_string(filename).unwrap();
view! {
<Tab index>
<h2>{filename.to_string()}</h2>
<p>{content}</p>
</Tab>
}
})
.collect_view()
};
view! {
<h1>"Welcome to Leptos!"</h1>
<p>"Click any of the tabs below to read a recipe."</p>
<Tabs labels>
<div>{tabs()}</div>
</Tabs>
}
}
```
Uh... What?
If youre used to using Leptos, you know that you just cant do this. All code in the body of components has to run on the server (to be rendered to HTML) and in the browser (to hydrate), so you cant just call `std::fs`; it will panic, because theres no access to the local filesystem (and certainly not to the server filesystem!) in the browser. This would be a security nightmare!
Except... wait. Were in islands mode. This `HomePage` component _really does_ only run on the server. So we can, in fact, just use ordinary server code like this.
> **Is this a dumb example?** Yes! Synchronously reading from three different local files in a `.map()` is not a good choice in real life. The point here is just to demonstrate that this is, definitely, server-only content.
Go ahead and create three files in the root of the project called `a.txt`, `b.txt`, and `c.txt`, and fill them in with whatever content youd like.
Refresh the page and you should see the content in the browser. Edit the files and refresh again; it will be updated.
You can pass server-only content from a `#[component]` into the children of an `#[island]`, without the island needing to know anything about how to access that data or render that content.
**This is really important.** Passing server `children` to islands means that you can keep islands small. Ideally, you dont want to slap and `#[island]` around a whole chunk of your page. You want to break that chunk out into an interactive piece, which can be an `#[island]`, and a bunch of additional server content that can be passed to that island as `children`, so that the non-interactive subsections of an interactive part of the page can be kept out of the WASM binary.
## Passing Context Between Islands
These arent really “tabs” yet: they just show every tab, all the time. So lets add some simple logic to our `Tabs` and `Tab` components.
Well modify `Tabs` to create a simple `selected` signal. We provide the read half via context, and set the value of the signal whenever someone clicks one of our buttons.
```rust
#[island]
fn Tabs(labels: Vec<String>, children: Children) -> impl IntoView {
let (selected, set_selected) = create_signal(0);
provide_context(selected);
let buttons = labels
.into_iter()
.enumerate()
.map(|(index, label)| view! {
<button on:click=move |_| set_selected(index)>
{label}
</button>
})
.collect_view();
// ...
```
And lets modify the `Tab` island to use that context to show or hide itself:
```rust
#[island]
fn Tab(children: Children) -> impl IntoView {
let selected = expect_context::<ReadSignal<usize>>();
view! {
<div style:display=move || if selected() {
"block"
} else {
"none"
}>
// ...
```
Now the tabs behave exactly as Id expect. `Tabs` passes the signal via context to each `Tab`, which uses it to determine whether it should be open or not.
> Thats why in `HomePage`, I made `let tabs = move ||` a function, and called it like `{tabs()}`: creating the tabs lazily this way meant that the `Tabs` island would already have provided the `selected` context by the time each `Tab` went looking for it.
Our complete tabs demo is about 220kb uncompressed: not the smallest demo in the world, but still about a third smaller than the counter button! Just for kicks, I built the same demo without islands mode, using `#[server]` functions and `Suspense`. and it was 429kb. So again, this was about a 50% savings in binary size. And this app includes quite minimal server-only content: remember that as we add additional server-only components and pages, this 220 will not grow.
## Overview
This demo may seem pretty basic. It is. But there are a number of immediate takeaways:
- **50% WASM binary size reduction**, which means measurable improvements in time to interactivity and initial load times for clients.
- **Reduced HTML page size.** This one is less obvious, but its true and important: HTML generated from `#[component]`s doesnt need all the hydration IDs and other boilerplate added.
- **Reduced data serialization costs.** Creating a resource and reading it on the client means you need to serialize the data, so it can be used for hydration. If youve also read that data to create HTML in a `Suspense`, you end up with “double data,” i.e., the same exact data is both rendered to HTML and serialized as JSON, increasing the size of responses, and therefore slowing them down.
- **Easily use server-only APIs** inside a `#[component]` as if it were a normal, native Rust function running on the server—which, in islands mode, it is!
- **Reduced `#[server]`/`create_resource`/`Suspense` boilerplate** for loading server data.
## Future Exploration
The `experimental-islands` feature included in 0.5 reflects work at the cutting edge of what frontend web frameworks are exploring right now. As it stands, our islands approach is very similar to Astro (before its recent View Transitions support): it allows you to build a traditional server-rendered, multi-page app and pretty seamlessly integrate islands of interactivity.
There are some small improvements that will be easy to add. For example, we can do something very much like Astro's View Transitions approach:
- add client-side routing for islands apps by fetching subsequent navigations from the server and replacing the HTML document with the new one
- add animated transitions between the old and new document using the View Transitions API
- support explicit persistent islands, i.e., islands that you can mark with unique IDs (something like `persist:searchbar` on the component in the view), which can be copied over from the old to the new document without losing their current state
There are other, larger architectural changes that Im [not sold on yet](https://github.com/leptos-rs/leptos/issues/1830).
## Additional Information
Check out the [islands PR](https://github.com/leptos-rs/leptos/pull/1660), [roadmap](https://github.com/leptos-rs/leptos/issues/1830), and [Hackernews demo](https://github.com/leptos-rs/leptos/tree/main/examples/hackernews_islands_axum) for additional discussion.
## Demo Code
```rust
use leptos::*;
use leptos_router::*;
#[component]
pub fn App() -> impl IntoView {
view! {
<Router>
<main style="background-color: lightblue; padding: 10px">
<Routes>
<Route path="" view=HomePage/>
</Routes>
</main>
</Router>
}
}
/// Renders the home page of your application.
#[component]
fn HomePage() -> impl IntoView {
let files = ["a.txt", "b.txt", "c.txt"];
let labels = files.iter().copied().map(Into::into).collect();
let tabs = move || {
files
.into_iter()
.enumerate()
.map(|(index, filename)| {
let content = std::fs::read_to_string(filename).unwrap();
view! {
<Tab index>
<div style="background-color: lightblue; padding: 10px">
<h2>{filename.to_string()}</h2>
<p>{content}</p>
</div>
</Tab>
}
})
.collect_view()
};
view! {
<h1>"Welcome to Leptos!"</h1>
<p>"Click any of the tabs below to read a recipe."</p>
<Tabs labels>
<div>{tabs()}</div>
</Tabs>
}
}
#[island]
fn Tabs(labels: Vec<String>, children: Children) -> impl IntoView {
let (selected, set_selected) = create_signal(0);
provide_context(selected);
let buttons = labels
.into_iter()
.enumerate()
.map(|(index, label)| {
view! {
<button on:click=move |_| set_selected(index)>
{label}
</button>
}
})
.collect_view();
view! {
<div
style="display: flex; width: 100%; justify-content: space-around;\
background-color: lightgreen; padding: 10px;"
>
{buttons}
</div>
{children()}
}
}
#[island]
fn Tab(index: usize, children: Children) -> impl IntoView {
let selected = expect_context::<ReadSignal<usize>>();
view! {
<div
style:background-color="lightgreen"
style:padding="10px"
style:display=move || if selected() == index {
"block"
} else {
"none"
}
>
{children()}
</div>
}
}
```

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@@ -1,49 +0,0 @@
# Metadata
So far, everything weve rendered has been inside the `<body>` of the HTML document. And this makes sense. After all, everything you can see on a web page lives inside the `<body>`.
However, there are plenty of occasions where you might want to update something inside the `<head>` of the document using the same reactive primitives and component patterns you use for your UI.
Thats where the [`leptos_meta`](https://docs.rs/leptos_meta/latest/leptos_meta/) package comes in.
## Metadata Components
`leptos_meta` provides special components that let you inject data from inside components anywhere in your application into the `<head>`:
[`<Title/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Title.html) allows you to set the documents title from any component. It also takes a `formatter` function that can be used to apply the same format to the title set by other pages. So, for example, if you put `<Title formatter=|text| format!("{text} — My Awesome Site")/>` in your `<App/>` component, and then `<Title text="Page 1"/>` and `<Title text="Page 2"/>` on your routes, youll get `Page 1 — My Awesome Site` and `Page 2 — My Awesome Site`.
[`<Link/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Link.html) takes the standard attributes of the `<link>` element.
[`<Stylesheet/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Stylesheet.html) creates a `<link rel="stylesheet">` with the `href` you give.
[`<Style/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Style.html) creates a `<style>` with the children you pass in (usually a string). You can use this to import some custom CSS from another file at compile time `<Style>{include_str!("my_route.css")}</Style>`.
[`<Meta/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Meta.html) lets you set `<meta>` tags with descriptions and other metadata.
## `<Script/>` and `<script>`
`leptos_meta` also provides a [`<Script/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Script.html) component, and its worth pausing here for a second. All of the other components weve considered inject `<head>`-only elements in the `<head>`. But a `<script>` can also be included in the body.
Theres a very simple way to determine whether you should use a capital-S `<Script/>` component or a lowercase-s `<script>` element: the `<Script/>` component will be rendered in the `<head>`, and the `<script>` element will be rendered wherever in the `<body>` of your user interface you put it in, alongside other normal HTML elements. These cause JavaScript to load and run at different times, so use whichever is appropriate to your needs.
## `<Body/>` and `<Html/>`
There are even a couple elements designed to make semantic HTML and styling easier. [`<Html/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Html.html) lets you set the `lang` and `dir` on your `<html>` tag from your application code. `<Html/>` and [`<Body/>`](https://docs.rs/leptos_meta/latest/leptos_meta/fn.Html.html) both have `class` props that let you set their respective `class` attributes, which is sometimes needed by CSS frameworks for styling.
`<Body/>` and `<Html/>` both also have `attributes` props which can be used to set any number of additional attributes on them via the `attr:` syntax:
```rust
<Html
lang="he"
dir="rtl"
attr:data-theme="dark"
/>
```
## Metadata and Server Rendering
Now, some of this is useful in any scenario, but some of it is especially important for search-engine optimization (SEO). Making sure you have things like appropriate `<title>` and `<meta>` tags is crucial. Modern search engine crawlers do handle client-side rendering, i.e., apps that are shipped as an empty `index.html` and rendered entirely in JS/WASM. But they prefer to receive pages in which your app has been rendered to actual HTML, with metadata in the `<head>`.
This is exactly what `leptos_meta` is for. And in fact, during server rendering, this is exactly what it does: collect all the `<head>` content youve declared by using its components throughout your application, and then inject it into the actual `<head>`.
But Im getting ahead of myself. We havent actually talked about server-side rendering yet. As a matter of fact... Lets do that next!

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@@ -1,36 +0,0 @@
# Progressive Enhancement (and Graceful Degradation)
Ive been driving around Boston for about fifteen years. If you dont know Boston, let me tell you: Massachusetts has some of the most aggressive drivers(and pedestrians!) in the world. Ive learned to practice whats sometimes called “defensive driving”: assuming that someones about to swerve in front of you at an intersection when you have the right of way, preparing for a pedestrian to cross into the street at any moment, and driving accordingly.
“Progressive enhancement” is the “defensive driving” of web design. Or really, thats “graceful degradation,” although theyre two sides of the same coin, or the same process, from two different directions.
**Progressive enhancement**, in this context, means beginning with a simple HTML site or application that works for any user who arrives at your page, and gradually enhancing it with layers of additional features: CSS for styling, JavaScript for interactivity, WebAssembly for Rust-powered interactivity; using particular Web APIs for a richer experience if theyre available and as needed.
**Graceful degradation** means handling failure gracefully when parts of that stack of enhancement *arent* available. Here are some sources of failure your users might encounter in your app:
- Their browser doesnt support WebAssembly because it needs to be updated.
- Their browser cant support WebAssembly because browser updates are limited to newer OS versions, which cant be installed on the device. (Looking at you, Apple.)
- They have WASM turned off for security or privacy reasons.
- They have JavaScript turned off for security or privacy reasons.
- JavaScript isnt supported on their device (for example, some accessibility devices only support HTML browsing)
- The JavaScript (or WASM) never arrived at their device because they walked outside and lost WiFi.
- They stepped onto a subway car after loading the initial page and subsequent navigations cant load data.
- ... and so on.
How much of your app still works if one of these holds true? Two of them? Three?
If the answer is something like “95%... okay, then 90%... okay, then 75%,” thats graceful degradation. If the answer is “my app shows a blank screen unless everything works correctly,” thats... rapid unscheduled disassembly.
**Graceful degradation is especially important for WASM apps,** because WASM is the newest and least-likely-to-be-supported of the four languages that run in the browser (HTML, CSS, JS, WASM).
Luckily, weve got some tools to help.
## Defensive Design
There are a few practices that can help your apps degrade more gracefully:
1. **Server-side rendering.** Without SSR, your app simply doesnt work without both JS and WASM loading. In some cases this may be appropriate (think internal apps gated behind a login) but in others its simply broken.
2. **Native HTML elements.** Use HTML elements that do the things that you want, without additional code: `<a>` for navigation (including to hashes within the page), `<details>` for an accordion, `<form>` to persist information in the URL, etc.
3. **URL-driven state.** The more of your global state is stored in the URL (as a route param or part of the query string), the more of the page can be generated during server rendering and updated by an `<a>` or a `<form>`, which means that not only navigations but state changes can work without JS/WASM.
4. **[`SsrMode::PartiallyBlocked` or `SsrMode::InOrder`](https://docs.rs/leptos_router/latest/leptos_router/enum.SsrMode.html).** Out-of-order streaming requires a small amount of inline JS, but can fail if 1) the connection is broken halfway through the response or 2) the clients device doesnt support JS. Async streaming will give a complete HTML page, but only after all resources load. In-order streaming begins showing pieces of the page sooner, in top-down order. “Partially-blocked” SSR builds on out-of-order streaming by replacing `<Suspense/>` fragments that read from blocking resources on the server. This adds marginally to the initial response time (because of the `O(n)` string replacement work), in exchange for a more complete initial HTML response. This can be a good choice for situations in which theres a clear distinction between “more important” and “less important” content, e.g., blog post vs. comments, or product info vs. reviews. If you choose to block on all the content, youve essentially recreated async rendering.
5. **Leaning on `<form>`s.** Theres been a bit of a `<form>` renaissance recently, and its no surprise. The ability of a `<form>` to manage complicated `POST` or `GET` requests in an easily-enhanced way makes it a powerful tool for graceful degradation. The example in [the `<Form/>` chapter](../router/20_form.md), for example, would work fine with no JS/WASM: because it uses a `<form method="GET">` to persist state in the URL, it works with pure HTML by making normal HTTP requests and then progressively enhances to use client-side navigations instead.
Theres one final feature of the framework that we havent seen yet, and which builds on this characteristic of forms to build powerful applications: the `<ActionForm/>`.

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@@ -1,58 +0,0 @@
# `<ActionForm/>`
[`<ActionForm/>`](https://docs.rs/leptos_router/latest/leptos_router/fn.ActionForm.html) is a specialized `<Form/>` that takes a server action, and automatically dispatches it on form submission. This allows you to call a server function directly from a `<form>`, even without JS/WASM.
The process is simple:
1. Define a server function using the [`#[server]` macro](https://docs.rs/leptos/latest/leptos/attr.server.html) (see [Server Functions](../server/25_server_functions.md).)
2. Create an action using [`create_server_action`](https://docs.rs/leptos/latest/leptos/fn.create_server_action.html), specifying the type of the server function youve defined.
3. Create an `<ActionForm/>`, providing the server action in the `action` prop.
4. Pass the named arguments to the server function as form fields with the same names.
> **Note:** `<ActionForm/>` only works with the default URL-encoded `POST` encoding for server functions, to ensure graceful degradation/correct behavior as an HTML form.
```rust
#[server(AddTodo, "/api")]
pub async fn add_todo(title: String) -> Result<(), ServerFnError> {
todo!()
}
#[component]
fn AddTodo() -> impl IntoView {
let add_todo = create_server_action::<AddTodo>();
// holds the latest *returned* value from the server
let value = add_todo.value();
// check if the server has returned an error
let has_error = move || value.with(|val| matches!(val, Some(Err(_))));
view! {
<ActionForm action=add_todo>
<label>
"Add a Todo"
// `title` matches the `title` argument to `add_todo`
<input type="text" name="title"/>
</label>
<input type="submit" value="Add"/>
</ActionForm>
}
}
```
Its really that easy. With JS/WASM, your form will submit without a page reload, storing its most recent submission in the `.input()` signal of the action, its pending status in `.pending()`, and so on. (See the [`Action`](https://docs.rs/leptos/latest/leptos/struct.Action.html) docs for a refresher, if you need.) Without JS/WASM, your form will submit with a page reload. If you call a `redirect` function (from `leptos_axum` or `leptos_actix`) it will redirect to the correct page. By default, it will redirect back to the page youre currently on. The power of HTML, HTTP, and isomorphic rendering mean that your `<ActionForm/>` simply works, even with no JS/WASM.
## Client-Side Validation
Because the `<ActionForm/>` is just a `<form>`, it fires a `submit` event. You can use either HTML validation, or your own client-side validation logic in an `on:submit`. Just call `ev.prevent_default()` to prevent submission.
The [`FromFormData`](https://docs.rs/leptos_router/latest/leptos_router/trait.FromFormData.html) trait can be helpful here, for attempting to parse your server functions data type from the submitted form.
```rust
let on_submit = move |ev| {
let data = AddTodo::from_event(&ev);
// silly example of validation: if the todo is "nope!", nope it
if data.is_err() || data.unwrap().title == "nope!" {
// ev.prevent_default() will prevent form submission
ev.prevent_default();
}
}
```

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@@ -1,329 +0,0 @@
# Responding to Changes with `create_effect`
Weve made it this far without having mentioned half of the reactive system: effects.
Reactivity works in two halves: updating individual reactive values (“signals”) notifies the pieces of code that depend on them (“effects”) that they need to run again. These two halves of the reactive system are inter-dependent. Without effects, signals can change within the reactive system but never be observed in a way that interacts with the outside world. Without signals, effects run once but never again, as theres no observable value to subscribe to. Effects are quite literally “side effects” of the reactive system: they exist to synchronize the reactive system with the non-reactive world outside it.
Hidden behind the whole reactive DOM renderer that weve seen so far is a function called `create_effect`.
[`create_effect`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_effect.html) takes a function as its argument. It immediately runs the function. If you access any reactive signal inside that function, it registers the fact that the effect depends on that signal with the reactive runtime. Whenever one of the signals that the effect depends on changes, the effect runs again.
```rust
let (a, set_a) = create_signal(0);
let (b, set_b) = create_signal(0);
create_effect(move |_| {
// immediately prints "Value: 0" and subscribes to `a`
log::debug!("Value: {}", a());
});
```
The effect function is called with an argument containing whatever value it returned the last time it ran. On the initial run, this is `None`.
By default, effects **do not run on the server**. This means you can call browser-specific APIs within the effect function without causing issues. If you need an effect to run on the server, use [`create_isomorphic_effect`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_isomorphic_effect.html).
## Autotracking and Dynamic Dependencies
If youre familiar with a framework like React, you might notice one key difference. React and similar frameworks typically require you to pass a “dependency array,” an explicit set of variables that determine when the effect should rerun.
Because Leptos comes from the tradition of synchronous reactive programming, we dont need this explicit dependency list. Instead, we automatically track dependencies depending on which signals are accessed within the effect.
This has two effects (no pun intended). Dependencies are:
1. **Automatic**: You dont need to maintain a dependency list, or worry about what should or shouldnt be included. The framework simply tracks which signals might cause the effect to rerun, and handles it for you.
2. **Dynamic**: The dependency list is cleared and updated every time the effect runs. If your effect contains a conditional (for example), only signals that are used in the current branch are tracked. This means that effects rerun the absolute minimum number of times.
> If this sounds like magic, and if you want a deep dive into how automatic dependency tracking works, [check out this video](https://www.youtube.com/watch?v=GWB3vTWeLd4). (Apologies for the low volume!)
## Effects as Zero-Cost-ish Abstraction
While theyre not a “zero-cost abstraction” in the most technical sense—they require some additional memory use, exist at runtime, etc.—at a higher level, from the perspective of whatever expensive API calls or other work youre doing within them, effects are a zero-cost abstraction. They rerun the absolute minimum number of times necessary, given how youve described them.
Imagine that Im creating some kind of chat software, and I want people to be able to display their full name, or just their first name, and to notify the server whenever their name changes:
```rust
let (first, set_first) = create_signal(String::new());
let (last, set_last) = create_signal(String::new());
let (use_last, set_use_last) = create_signal(true);
// this will add the name to the log
// any time one of the source signals changes
create_effect(move |_| {
log(
if use_last() {
format!("{} {}", first(), last())
} else {
first()
},
)
});
```
If `use_last` is `true`, effect should rerun whenever `first`, `last`, or `use_last` changes. But if I toggle `use_last` to `false`, a change in `last` will never cause the full name to change. In fact, `last` will be removed from the dependency list until `use_last` toggles again. This saves us from sending multiple unnecessary requests to the API if I change `last` multiple times while `use_last` is still `false`.
## To `create_effect`, or not to `create_effect`?
Effects are intended to run _side-effects_ of the system, not to synchronize state _within_ the system. In other words: dont write to signals within effects.
If you need to define a signal that depends on the value of other signals, use a derived signal or [`create_memo`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.create_memo.html).
If you need to synchronize some reactive value with the non-reactive world outside—like a web API, the console, the filesystem, or the DOM—create an effect.
> If youre curious for more information about when you should and shouldnt use `create_effect`, [check out this video](https://www.youtube.com/watch?v=aQOFJQ2JkvQ) for a more in-depth consideration!
## Effects and Rendering
Weve managed to get this far without mentioning effects because theyre built into the Leptos DOM renderer. Weve seen that you can create a signal and pass it into the `view` macro, and it will update the relevant DOM node whenever the signal changes:
```rust
let (count, set_count) = create_signal(0);
view! {
<p>{count}</p>
}
```
This works because the framework essentially creates an effect wrapping this update. You can imagine Leptos translating this view into something like this:
```rust
let (count, set_count) = create_signal(0);
// create a DOM element
let p = create_element("p");
// create an effect to reactively update the text
create_effect(move |prev_value| {
// first, access the signals value and convert it to a string
let text = count().to_string();
// if this is different from the previous value, update the node
if prev_value != Some(text) {
p.set_text_content(&text);
}
// return this value so we can memoize the next update
text
});
```
Every time `count` is updated, this effect wil rerun. This is what allows reactive, fine-grained updates to the DOM.
## Explicit, Cancelable Tracking with `watch`
In addition to `create_effect`, Leptos provides a [`watch`](https://docs.rs/leptos_reactive/latest/leptos_reactive/fn.watch.html) function, which can be used for two main purposes:
1. Separating tracking and responding to changes by explicitly passing in a set of values to track.
2. Canceling tracking by calling a stop function.
Like `create_resource`, `watch` takes a first argument, which is reactively tracked, and a second, which is not. Whenever a reactive value in its `deps` argument is changed, the `callback` is run. `watch` returns a function that can be called to stop tracking the dependencies.
```rust
let (num, set_num) = create_signal(0);
let stop = watch(
move || num.get(),
move |num, prev_num, _| {
log::debug!("Number: {}; Prev: {:?}", num, prev_num);
},
false,
);
set_num.set(1); // > "Number: 1; Prev: Some(0)"
stop(); // stop watching
set_num.set(2); // (nothing happens)
```
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/14-effect-0-5-d6hkch?file=%2Fsrc%2Fmain.rs%3A1%2C1)
<iframe src="https://codesandbox.io/p/sandbox/14-effect-0-5-d6hkch?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::html::Input;
use leptos::*;
#[component]
fn App() -> impl IntoView {
// Just making a visible log here
// You can ignore this...
let log = create_rw_signal::<Vec<String>>(vec![]);
let logged = move || log().join("\n");
provide_context(log);
view! {
<CreateAnEffect/>
<pre>{logged}</pre>
}
}
#[component]
fn CreateAnEffect() -> impl IntoView {
let (first, set_first) = create_signal(String::new());
let (last, set_last) = create_signal(String::new());
let (use_last, set_use_last) = create_signal(true);
// this will add the name to the log
// any time one of the source signals changes
create_effect(move |_| {
log(
if use_last() {
format!("{} {}", first(), last())
} else {
first()
},
)
});
view! {
<h1><code>"create_effect"</code> " Version"</h1>
<form>
<label>
"First Name"
<input type="text" name="first" prop:value=first
on:change=move |ev| set_first(event_target_value(&ev))
/>
</label>
<label>
"Last Name"
<input type="text" name="last" prop:value=last
on:change=move |ev| set_last(event_target_value(&ev))
/>
</label>
<label>
"Show Last Name"
<input type="checkbox" name="use_last" prop:checked=use_last
on:change=move |ev| set_use_last(event_target_checked(&ev))
/>
</label>
</form>
}
}
#[component]
fn ManualVersion() -> impl IntoView {
let first = create_node_ref::<Input>();
let last = create_node_ref::<Input>();
let use_last = create_node_ref::<Input>();
let mut prev_name = String::new();
let on_change = move |_| {
log(" listener");
let first = first.get().unwrap();
let last = last.get().unwrap();
let use_last = use_last.get().unwrap();
let this_one = if use_last.checked() {
format!("{} {}", first.value(), last.value())
} else {
first.value()
};
if this_one != prev_name {
log(&this_one);
prev_name = this_one;
}
};
view! {
<h1>"Manual Version"</h1>
<form on:change=on_change>
<label>
"First Name"
<input type="text" name="first"
node_ref=first
/>
</label>
<label>
"Last Name"
<input type="text" name="last"
node_ref=last
/>
</label>
<label>
"Show Last Name"
<input type="checkbox" name="use_last"
checked
node_ref=use_last
/>
</label>
</form>
}
}
#[component]
fn EffectVsDerivedSignal() -> impl IntoView {
let (my_value, set_my_value) = create_signal(String::new());
// Don't do this.
/*let (my_optional_value, set_optional_my_value) = create_signal(Option::<String>::None);
create_effect(move |_| {
if !my_value.get().is_empty() {
set_optional_my_value(Some(my_value.get()));
} else {
set_optional_my_value(None);
}
});*/
// Do this
let my_optional_value =
move || (!my_value.with(String::is_empty)).then(|| Some(my_value.get()));
view! {
<input
prop:value=my_value
on:input= move |ev| set_my_value(event_target_value(&ev))
/>
<p>
<code>"my_optional_value"</code>
" is "
<code>
<Show
when=move || my_optional_value().is_some()
fallback=|| view! { "None" }
>
"Some(\"" {my_optional_value().unwrap()} "\")"
</Show>
</code>
</p>
}
}
#[component]
pub fn Show<F, W, IV>(
/// The components Show wraps
children: Box<dyn Fn() -> Fragment>,
/// A closure that returns a bool that determines whether this thing runs
when: W,
/// A closure that returns what gets rendered if the when statement is false
fallback: F,
) -> impl IntoView
where
W: Fn() -> bool + 'static,
F: Fn() -> IV + 'static,
IV: IntoView,
{
let memoized_when = create_memo(move |_| when());
move || match memoized_when.get() {
true => children().into_view(),
false => fallback().into_view(),
}
}
fn log(msg: impl std::fmt::Display) {
let log = use_context::<RwSignal<Vec<String>>>().unwrap();
log.update(|log| log.push(msg.to_string()));
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>

View File

@@ -1,5 +0,0 @@
# Reactivity
Leptos is built on top of a fine-grained reactive system, designed to run expensive side effects (like rendering something in a browser, or making a network request) as infrequently as possible in response to change, reactive values.
So far weve seen signals in action. These chapters will go into a bit more depth, and look at effects, which are the other half of the story.

View File

@@ -1,140 +0,0 @@
# Working with Signals
So far weve used some simple examples of [`create_signal`](https://docs.rs/leptos/latest/leptos/fn.create_signal.html), which returns a [`ReadSignal`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html) getter and a [`WriteSignal`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html) setter.
## Getting and Setting
There are four basic signal operations:
1. [`.get()`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html#impl-SignalGet%3CT%3E-for-ReadSignal%3CT%3E) clones the current value of the signal and tracks any future changes to the value reactively.
2. [`.with()`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html#impl-SignalWith%3CT%3E-for-ReadSignal%3CT%3E) takes a function, which receives the current value of the signal by reference (`&T`), and tracks any future changes.
3. [`.set()`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html#impl-SignalSet%3CT%3E-for-WriteSignal%3CT%3E) replaces the current value of the signal and notifies any subscribers that they need to update.
4. [`.update()`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html#impl-SignalUpdate%3CT%3E-for-WriteSignal%3CT%3E) takes a function, which receives a mutable reference to the current value of the signal (`&mut T`), and notifies any subscribers that they need to update. (`.update()` doesnt return the value returned by the closure, but you can use [`.try_update()`](https://docs.rs/leptos/latest/leptos/trait.SignalUpdate.html#tymethod.try_update) if you need to; for example, if youre removing an item from a `Vec<_>` and want the removed item.)
Calling a `ReadSignal` as a function is syntax sugar for `.get()`. Calling a `WriteSignal` as a function is syntax sugar for `.set()`. So
```rust
let (count, set_count) = create_signal(0);
set_count(1);
logging::log!(count());
```
is the same as
```rust
let (count, set_count) = create_signal(0);
set_count.set(1);
logging::log!(count.get());
```
You might notice that `.get()` and `.set()` can be implemented in terms of `.with()` and `.update()`. In other words, `count.get()` is identical with `count.with(|n| n.clone())`, and `count.set(1)` is implemented by doing `count.update(|n| *n = 1)`.
But of course, `.get()` and `.set()` (or the plain function-call forms!) are much nicer syntax.
However, there are some very good use cases for `.with()` and `.update()`.
For example, consider a signal that holds a `Vec<String>`.
```rust
let (names, set_names) = create_signal(Vec::new());
if names().is_empty() {
set_names(vec!["Alice".to_string()]);
}
```
In terms of logic, this is simple enough, but its hiding some significant inefficiencies. Remember that `names().is_empty()` is sugar for `names.get().is_empty()`, which clones the value (its `names.with(|n| n.clone()).is_empty()`). This means we clone the whole `Vec<String>`, run `is_empty()`, and then immediately throw away the clone.
Likewise, `set_names` replaces the value with a whole new `Vec<_>`. This is fine, but we might as well just mutate the original `Vec<_>` in place.
```rust
let (names, set_names) = create_signal(Vec::new());
if names.with(|names| names.is_empty()) {
set_names.update(|names| names.push("Alice".to_string()));
}
```
Now our function simply takes `names` by reference to run `is_empty()`, avoiding that clone.
And if you have Clippy on, or if you have sharp eyes, you may notice we can make this even neater:
```rust
if names.with(Vec::is_empty) {
// ...
}
```
After all, `.with()` simply takes a function that takes the value by reference. Since `Vec::is_empty` takes `&self`, we can pass it in directly and avoid the unnecessary closure.
There are some helper macros to make using `.with()` and `.update()` easier to use, especially when using multiple signals.
```rust
let (first, _) = create_signal("Bob".to_string());
let (middle, _) = create_signal("J.".to_string());
let (last, _) = create_signal("Smith".to_string());
```
If you wanted to concatenate these 3 signals together without unnecessary cloning, you would have to write something like:
```rust
let name = move || {
first.with(|first| {
middle.with(|middle| last.with(|last| format!("{first} {middle} {last}")))
})
};
```
Which is very long and annoying to write.
Instead, you can use the `with!` macro to get references to all the signals at the same time.
```rust
let name = move || with!(|first, middle, last| format!("{first} {middle} {last}"));
```
This expands to the same thing as above. Take a look at the `with!` docs for more info, and the corresponding macros `update!`, `with_value!` and `update_value!`.
## Making signals depend on each other
Often people ask about situations in which some signal needs to change based on some other signals value. There are three good ways to do this, and one thats less than ideal but okay under controlled circumstances.
### Good Options
**1) B is a function of A.** Create a signal for A and a derived signal or memo for B.
```rust
let (count, set_count) = create_signal(1);
let derived_signal_double_count = move || count() * 2;
let memoized_double_count = create_memo(move |_| count() * 2);
```
> For guidance on whether to use a derived signal or a memo, see the docs for [`create_memo`](https://docs.rs/leptos/latest/leptos/fn.create_memo.html)
**2) C is a function of A and some other thing B.** Create signals for A and B and a derived signal or memo for C.
```rust
let (first_name, set_first_name) = create_signal("Bridget".to_string());
let (last_name, set_last_name) = create_signal("Jones".to_string());
let full_name = move || format!("{} {}", first_name(), last_name());
```
**3) A and B are independent signals, but sometimes updated at the same time.** When you make the call to update A, make a separate call to update B.
```rust
let (age, set_age) = create_signal(32);
let (favorite_number, set_favorite_number) = create_signal(42);
// use this to handle a click on a `Clear` button
let clear_handler = move |_| {
set_age(0);
set_favorite_number(0);
};
```
### If you really must...
**4) Create an effect to write to B whenever A changes.** This is officially discouraged, for several reasons:
a) It will always be less efficient, as it means every time A updates you do two full trips through the reactive process. (You set A, which causes the effect to run, as well as any other effects that depend on A. Then you set B, which causes any effects that depend on B to run.)
b) It increases your chances of accidentally creating things like infinite loops or over-re-running effects. This is the kind of ping-ponging, reactive spaghetti code that was common in the early 2010s and that we try to avoid with things like read-write segregation and discouraging writing to signals from effects.
In most situations, its best to rewrite things such that theres a clear, top-down data flow based on derived signals or memos. But this isnt the end of the world.
> Im intentionally not providing an example here. Read the [`create_effect`](https://docs.rs/leptos/latest/leptos/fn.create_effect.html) docs to figure out how this would work.

View File

@@ -24,7 +24,7 @@ use leptos_router::*;
Routing behavior is provided by the [`<Router/>`](https://docs.rs/leptos_router/latest/leptos_router/fn.Router.html) component. This should usually be somewhere near the root of your application, the rest of the app.
> You shouldnt try to use multiple `<Router/>`s in your app. Remember that the router drives global state: if you have multiple routers, which one decides what to do when the URL changes?
> You shouldnt try to use multiple `<Router/>`s in your app. Remember that the router drives global state: if you have multiple routers, which ones decides what to do when the URL changes?
Lets start with a simple `<App/>` component using the router:
@@ -33,7 +33,7 @@ use leptos::*;
use leptos_router::*;
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
view! {
<Router>
<nav>
@@ -58,7 +58,7 @@ use leptos::*;
use leptos_router::*;
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
view! {
<Router>
<nav>
@@ -83,62 +83,19 @@ The `path` can include
- dynamic, named parameters beginning with a colon (`/:id`),
- and/or a wildcard beginning with an asterisk (`/user/*any`)
The `view` is a function that returns a view. Any component with no props works here, as does a closure that returns some view.
The `view` is a function that takes a `Scope` and returns a view.
```rust
<Routes>
<Route path="/" view=Home/>
<Route path="/users" view=Users/>
<Route path="/users/:id" view=UserProfile/>
<Route path="/*any" view=|| view! { <h1>"Not Found"</h1> }/>
<Route path="/" view=|cx| view! { cx, <Home/> }/>
<Route path="/users" view=|cx| view! { cx, <Users/> }/>
<Route path="/users/:id" view=|cx| view! { cx, <UserProfile/> }/>
<Route path="/*any" view=|cx| view! { cx, <NotFound/> }/>
</Routes>
```
> `view` takes a `Fn() -> impl IntoView`. If a component has no props, it can be passed directly into the `view`. In this case, `view=Home` is just a shorthand for `|| view! { <Home/> }`.
> The router scores each route to see how good a match it is, so you can define your routes in any order.
Now if you navigate to `/` or to `/users` youll get the home page or the `<Users/>`. If you go to `/users/3` or `/blahblah` youll get a user profile or your 404 page (`<NotFound/>`). On every navigation, the router determines which `<Route/>` should be matched, and therefore what content should be displayed where the `<Routes/>` component is defined.
Note that you can define your routes in any order. The router scores each route to see how good a match it is, rather than simply trying to match them top to bottom.
Simple enough?
## Conditional Routes
`leptos_router` is based on the assumption that you have one and only one `<Routes/>` component in your app. It uses this to generate routes on the server side, optimize route matching by caching calculated branches, and render your application.
You should not conditionally render `<Routes/>` using another component like `<Show/>` or `<Suspense/>`.
```rust
// ❌ don't do this!
view! {
<Show when=|| is_loaded() fallback=|| view! { <p>"Loading"</p> }>
<Routes>
<Route path="/" view=Home/>
</Routes>
</Show>
}
```
Instead, you can use nested routing to render your `<Routes/>` once, and conditionally render the router outlet:
```rust
// ✅ do this instead!
view! {
<Routes>
// parent route
<Route path="/" view=move || {
view! {
// only show the outlet if data have loaded
<Show when=|| is_loaded() fallback=|| view! { <p>"Loading"</p> }>
<Outlet/>
</Show>
}
}>
// nested child route
<Route path="/" view=Home/>
</Route>
</Routes>
}
```
If this looks bizarre, dont worry! The next section of the book is about this kind of nested routing.

View File

@@ -4,10 +4,10 @@ We just defined the following set of routes:
```rust
<Routes>
<Route path="/" view=Home/>
<Route path="/users" view=Users/>
<Route path="/users/:id" view=UserProfile/>
<Route path="/*any" view=NotFound/>
<Route path="/" view=|cx| view! { cx, <Home /> }/>
<Route path="/users" view=|cx| view! { cx, <Users /> }/>
<Route path="/users/:id" view=|cx| view! { cx, <UserProfile /> }/>
<Route path="/*any" view=|cx| view! { cx, <NotFound /> }/>
</Routes>
```
@@ -17,11 +17,11 @@ Well... you can!
```rust
<Routes>
<Route path="/" view=Home/>
<Route path="/users" view=Users>
<Route path=":id" view=UserProfile/>
<Route path="/" view=|cx| view! { cx, <Home /> }/>
<Route path="/users" view=|cx| view! { cx, <Users /> }>
<Route path=":id" view=|cx| view! { cx, <UserProfile /> }/>
</Route>
<Route path="/*any" view=NotFound/>
<Route path="/*any" view=|cx| view! { cx, <NotFound /> }/>
</Routes>
```
@@ -39,8 +39,8 @@ Lets look back at our practical example.
```rust
<Routes>
<Route path="/users" view=Users/>
<Route path="/users/:id" view=UserProfile/>
<Route path="/users" view=|cx| view! { cx, <Users /> }/>
<Route path="/users/:id" view=|cx| view! { cx, <UserProfile /> }/>
</Routes>
```
@@ -53,8 +53,8 @@ Lets say I use nested routes instead:
```rust
<Routes>
<Route path="/users" view=Users>
<Route path=":id" view=UserProfile/>
<Route path="/users" view=|cx| view! { cx, <Users /> }>
<Route path=":id" view=|cx| view! { cx, <UserProfile /> }/>
</Route>
</Routes>
```
@@ -68,9 +68,9 @@ I actually need to add a fallback route
```rust
<Routes>
<Route path="/users" view=Users>
<Route path=":id" view=UserProfile/>
<Route path="" view=NoUser/>
<Route path="/users" view=|cx| view! { cx, <Users /> }>
<Route path=":id" view=|cx| view! { cx, <UserProfile /> }/>
<Route path="" view=|cx| view! { cx, <NoUser /> }/>
</Route>
</Routes>
```
@@ -94,9 +94,9 @@ You can easily define this with nested routes
```rust
<Routes>
<Route path="/contacts" view=ContactList>
<Route path=":id" view=ContactInfo/>
<Route path="" view=|| view! {
<Route path="/contacts" view=|cx| view! { cx, <ContactList/> }>
<Route path=":id" view=|cx| view! { cx, <ContactInfo/> }/>
<Route path="" view=|cx| view! { cx,
<p>"Select a contact to view more info."</p>
}/>
</Route>
@@ -107,13 +107,13 @@ You can go even deeper. Say you want to have tabs for each contacts address,
```rust
<Routes>
<Route path="/contacts" view=ContactList>
<Route path=":id" view=ContactInfo>
<Route path="" view=EmailAndPhone/>
<Route path="address" view=Address/>
<Route path="messages" view=Messages/>
<Route path="/contacts" view=|cx| view! { cx, <ContactList/> }>
<Route path=":id" view=|cx| view! { cx, <ContactInfo/> }>
<Route path="" view=|cx| view! { cx, <EmailAndPhone/> }/>
<Route path="address" view=|cx| view! { cx, <Address/> }/>
<Route path="messages" view=|cx| view! { cx, <Messages/> }/>
</Route>
<Route path="" view=|| view! {
<Route path="" view=|cx| view! { cx,
<p>"Select a contact to view more info."</p>
}/>
</Route>
@@ -124,7 +124,7 @@ You can go even deeper. Say you want to have tabs for each contacts address,
## `<Outlet/>`
Parent routes do not automatically render their nested routes. After all, they are just components; they dont know exactly where they should render their children, and “just stick it at the end of the parent component” is not a great answer.
Parent routes do not automatically render their nested routes. After all, they are just components; they dont know exactly where they should render their children, and “just stick at at the end of the parent component” is not a great answer.
Instead, you tell a parent component where to render any nested components with an `<Outlet/>` component. The `<Outlet/>` simply renders one of two things:
@@ -135,16 +135,16 @@ Thats all! But its important to know and to remember, because its a com
```rust
#[component]
pub fn ContactList() -> impl IntoView {
pub fn ContactList(cx: Scope) -> impl IntoView {
let contacts = todo!();
view! {
view! { cx,
<div style="display: flex">
// the contact list
<For each=contacts
key=|contact| contact.id
children=|contact| todo!()
/>
view=|cx, contact| todo!()
>
// the nested child, if any
// dont forget this!
<Outlet/>
@@ -153,43 +153,6 @@ pub fn ContactList() -> impl IntoView {
}
```
## Refactoring Route Definitions
You dont need to define all your routes in one place if you dont want to. You can refactor any `<Route/>` and its children out into a separate component.
For example, you can refactor the example above to use two separate components:
```rust
#[component]
fn App() -> impl IntoView {
view! {
<Router>
<Routes>
<Route path="/contacts" view=ContactList>
<ContactInfoRoutes/>
<Route path="" view=|| view! {
<p>"Select a contact to view more info."</p>
}/>
</Route>
</Routes>
</Router>
}
}
#[component(transparent)]
fn ContactInfoRoutes() -> impl IntoView {
view! {
<Route path=":id" view=ContactInfo>
<Route path="" view=EmailAndPhone/>
<Route path="address" view=Address/>
<Route path="messages" view=Messages/>
</Route>
}
}
```
This second component is a `#[component(transparent)]`, meaning it just returns its data, not a view: in this case, it's a [`RouteDefinition`](https://docs.rs/leptos_router/latest/leptos_router/struct.RouteDefinition.html) struct, which is what the `<Route/>` returns. As long as it is marked `#[component(transparent)]`, this sub-route can be defined wherever you want, and inserted as a component into your tree of route definitions.
## Nested Routing and Performance
All of this is nice, conceptually, but again—whats the big deal?
@@ -204,121 +167,6 @@ In fact, in this case, we dont even need to rerender the `<Contact/>` compone
> This sandbox includes a couple features (like nested routing) discussed in this section and the previous one, and a couple well cover in the rest of this chapter. The router is such an integrated system that it makes sense to provide a single example, so dont be surprised if theres anything you dont understand.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
use leptos_router::*;
#[component]
fn App() -> impl IntoView {
view! {
<Router>
<h1>"Contact App"</h1>
// this <nav> will show on every routes,
// because it's outside the <Routes/>
// note: we can just use normal <a> tags
// and the router will use client-side navigation
<nav>
<h2>"Navigation"</h2>
<a href="/">"Home"</a>
<a href="/contacts">"Contacts"</a>
</nav>
<main>
<Routes>
// / just has an un-nested "Home"
<Route path="/" view=|| view! {
<h3>"Home"</h3>
}/>
// /contacts has nested routes
<Route
path="/contacts"
view=ContactList
>
// if no id specified, fall back
<Route path=":id" view=ContactInfo>
<Route path="" view=|| view! {
<div class="tab">
"(Contact Info)"
</div>
}/>
<Route path="conversations" view=|| view! {
<div class="tab">
"(Conversations)"
</div>
}/>
</Route>
// if no id specified, fall back
<Route path="" view=|| view! {
<div class="select-user">
"Select a user to view contact info."
</div>
}/>
</Route>
</Routes>
</main>
</Router>
}
}
#[component]
fn ContactList() -> impl IntoView {
view! {
<div class="contact-list">
// here's our contact list component itself
<div class="contact-list-contacts">
<h3>"Contacts"</h3>
<A href="alice">"Alice"</A>
<A href="bob">"Bob"</A>
<A href="steve">"Steve"</A>
</div>
// <Outlet/> will show the nested child route
// we can position this outlet wherever we want
// within the layout
<Outlet/>
</div>
}
}
#[component]
fn ContactInfo() -> impl IntoView {
// we can access the :id param reactively with `use_params_map`
let params = use_params_map();
let id = move || params.with(|params| params.get("id").cloned().unwrap_or_default());
// imagine we're loading data from an API here
let name = move || match id().as_str() {
"alice" => "Alice",
"bob" => "Bob",
"steve" => "Steve",
_ => "User not found.",
};
view! {
<div class="contact-info">
<h4>{name}</h4>
<div class="tabs">
<A href="" exact=true>"Contact Info"</A>
<A href="conversations">"Conversations"</A>
</div>
// <Outlet/> here is the tabs that are nested
// underneath the /contacts/:id route
<Outlet/>
</div>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -36,22 +36,14 @@ struct ContactSearch {
```
> Note: The `Params` derive macro is located at `leptos::Params`, and the `Params` trait is at `leptos_router::Params`. If you avoid using glob imports like `use leptos::*;`, make sure youre importing the right one for the derive macro.
>
> If you are not using the `nightly` feature, you will get the error
>
> ```
> no function or associated item named `into_param` found for struct `std::string::String` in the current scope
> ```
>
> At the moment, supporting both `T: FromStr` and `Option<T>` for typed params requires a nightly feature. You can fix this by simply changing the struct to use `q: Option<String>` instead of `q: String`.
Now we can use them in a component. Imagine a URL that has both params and a query, like `/contacts/:id?q=Search`.
The typed versions return `Memo<Result<T, _>>`. Its a Memo so it reacts to changes in the URL. Its a `Result` because the params or query need to be parsed from the URL, and may or may not be valid.
The typed versions return `Memo<Result<T>, _>`. Its a Memo so it reacts to changes in the URL. Its a `Result` because the params or query need to be parsed from the URL, and may or may not be valid.
```rust
let params = use_params::<ContactParams>();
let query = use_query::<ContactSearch>();
let params = use_params::<ContactParams>(cx);
let query = use_query::<ContactSearch>(cx);
// id: || -> usize
let id = move || {
@@ -66,8 +58,8 @@ let id = move || {
The untyped versions return `Memo<ParamsMap>`. Again, its memo to react to changes in the URL. [`ParamsMap`](https://docs.rs/leptos_router/0.2.3/leptos_router/struct.ParamsMap.html) behaves a lot like any other map type, with a `.get()` method that returns `Option<&String>`.
```rust
let params = use_params_map();
let query = use_query_map();
let params = use_params_map(cx);
let query = use_query_map(cx);
// id: || -> Option<String>
let id = move || {
@@ -78,125 +70,10 @@ let id = move || {
This can get a little messy: deriving a signal that wraps an `Option<_>` or `Result<_>` can involve a couple steps. But its worth doing this for two reasons:
1. Its correct, i.e., it forces you to consider the cases, “What if the user doesnt pass a value for this query field? What if they pass an invalid value?”
2. Its performant. Specifically, when you navigate between different paths that match the same `<Route/>` with only params or the query changing, you can get fine-grained updates to different parts of your app without rerendering. For example, navigating between different contacts in our contact-list example does a targeted update to the name field (and eventually contact info) without needing to replace or rerender the wrapping `<Contact/>`. This is what fine-grained reactivity is for.
2. Its performant. Specifically, when you navigate between different paths that match the same `<Route/>` with only params or the query changing, you can get fine-grained updates to different parts of your app without rerendering. For example, navigating between different contacts in our contact-list example does a targeted update to the name field (and eventually contact info) without needing to replacing or rerender the wrapping `<Contact/>`. This is what fine-grained reactivity is for.
> This is the same example from the previous section. The router is such an integrated system that it makes sense to provide a single example highlighting multiple features, even if we havent explained them all yet.
> This is the same example from the previous section. The router is such an integrated system that it makes sense to provide a single example highlighting multiple features, even if we havent explain them all yet.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
use leptos_router::*;
#[component]
fn App() -> impl IntoView {
view! {
<Router>
<h1>"Contact App"</h1>
// this <nav> will show on every routes,
// because it's outside the <Routes/>
// note: we can just use normal <a> tags
// and the router will use client-side navigation
<nav>
<h2>"Navigation"</h2>
<a href="/">"Home"</a>
<a href="/contacts">"Contacts"</a>
</nav>
<main>
<Routes>
// / just has an un-nested "Home"
<Route path="/" view=|| view! {
<h3>"Home"</h3>
}/>
// /contacts has nested routes
<Route
path="/contacts"
view=ContactList
>
// if no id specified, fall back
<Route path=":id" view=ContactInfo>
<Route path="" view=|| view! {
<div class="tab">
"(Contact Info)"
</div>
}/>
<Route path="conversations" view=|| view! {
<div class="tab">
"(Conversations)"
</div>
}/>
</Route>
// if no id specified, fall back
<Route path="" view=|| view! {
<div class="select-user">
"Select a user to view contact info."
</div>
}/>
</Route>
</Routes>
</main>
</Router>
}
}
#[component]
fn ContactList() -> impl IntoView {
view! {
<div class="contact-list">
// here's our contact list component itself
<div class="contact-list-contacts">
<h3>"Contacts"</h3>
<A href="alice">"Alice"</A>
<A href="bob">"Bob"</A>
<A href="steve">"Steve"</A>
</div>
// <Outlet/> will show the nested child route
// we can position this outlet wherever we want
// within the layout
<Outlet/>
</div>
}
}
#[component]
fn ContactInfo() -> impl IntoView {
// we can access the :id param reactively with `use_params_map`
let params = use_params_map();
let id = move || params.with(|params| params.get("id").cloned().unwrap_or_default());
// imagine we're loading data from an API here
let name = move || match id().as_str() {
"alice" => "Alice",
"bob" => "Bob",
"steve" => "Steve",
_ => "User not found.",
};
view! {
<div class="contact-info">
<h4>{name}</h4>
<div class="tabs">
<A href="" exact=true>"Contact Info"</A>
<A href="conversations">"Conversations"</A>
</div>
// <Outlet/> here is the tabs that are nested
// underneath the /contacts/:id route
<Outlet/>
</div>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -11,145 +11,13 @@ The router will bail out of handling an `<a>` click under a number of situations
In other words, the router will only try to do a client-side navigation when its pretty sure it can handle it, and it will upgrade every `<a>` element to get this special behavior.
> This also means that if you need to opt out of client-side routing, you can do so easily. For example, if you have a link to another page on the same domain, but which isnt part of your Leptos app, you can just use `<a rel="external">` to tell the router it isnt something it can handle.
The router also provides an [`<A>`](https://docs.rs/leptos_router/latest/leptos_router/fn.A.html) component, which does two additional things:
1. Correctly resolves relative nested routes. Relative routing with ordinary `<a>` tags can be tricky. For example, if you have a route like `/post/:id`, `<A href="1">` will generate the correct relative route, but `<a href="1">` likely will not (depending on where it appears in your view.) `<A/>` resolves routes relative to the path of the nested route within which it appears.
2. Sets the `aria-current` attribute to `page` if this link is the active link (i.e., its a link to the page youre on). This is helpful for accessibility and for styling. For example, if you want to set the link a different color if its a link to the page youre currently on, you can match this attribute with a CSS selector.
## Navigating Programmatically
Your most-used methods of navigating between pages should be with `<a>` and `<form>` elements or with the enhanced `<A/>` and `<Form/>` components. Using links and forms to navigate is the best solution for accessibility and graceful degradation.
On occasion, though, youll want to navigate programmatically, i.e., call a function that can navigate to a new page. In that case, you should use the [`use_navigate`](https://docs.rs/leptos_router/latest/leptos_router/fn.use_navigate.html) function.
```rust
let navigate = leptos_router::use_navigate();
navigate("/somewhere", Default::default());
```
> You should almost never do something like `<button on:click=move |_| navigate(/* ... */)>`. Any `on:click` that navigates should be an `<a>`, for reasons of accessibility.
The second argument here is a set of [`NavigateOptions`](https://docs.rs/leptos_router/latest/leptos_router/struct.NavigateOptions.html), which includes options to resolve the navigation relative to the current route as the `<A/>` component does, replace it in the navigation stack, include some navigation state, and maintain the current scroll state on navigation.
> Once again, this is the same example. Check out the relative `<A/>` components, and take a look at the CSS in `index.html` to see the ARIA-based styling.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/16-router-0-5-4xp4zz?file=%2Fsrc%2Fmain.rs%3A102%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
use leptos_router::*;
#[component]
fn App() -> impl IntoView {
view! {
<Router>
<h1>"Contact App"</h1>
// this <nav> will show on every routes,
// because it's outside the <Routes/>
// note: we can just use normal <a> tags
// and the router will use client-side navigation
<nav>
<h2>"Navigation"</h2>
<a href="/">"Home"</a>
<a href="/contacts">"Contacts"</a>
</nav>
<main>
<Routes>
// / just has an un-nested "Home"
<Route path="/" view=|| view! {
<h3>"Home"</h3>
}/>
// /contacts has nested routes
<Route
path="/contacts"
view=ContactList
>
// if no id specified, fall back
<Route path=":id" view=ContactInfo>
<Route path="" view=|| view! {
<div class="tab">
"(Contact Info)"
</div>
}/>
<Route path="conversations" view=|| view! {
<div class="tab">
"(Conversations)"
</div>
}/>
</Route>
// if no id specified, fall back
<Route path="" view=|| view! {
<div class="select-user">
"Select a user to view contact info."
</div>
}/>
</Route>
</Routes>
</main>
</Router>
}
}
#[component]
fn ContactList() -> impl IntoView {
view! {
<div class="contact-list">
// here's our contact list component itself
<div class="contact-list-contacts">
<h3>"Contacts"</h3>
<A href="alice">"Alice"</A>
<A href="bob">"Bob"</A>
<A href="steve">"Steve"</A>
</div>
// <Outlet/> will show the nested child route
// we can position this outlet wherever we want
// within the layout
<Outlet/>
</div>
}
}
#[component]
fn ContactInfo() -> impl IntoView {
// we can access the :id param reactively with `use_params_map`
let params = use_params_map();
let id = move || params.with(|params| params.get("id").cloned().unwrap_or_default());
// imagine we're loading data from an API here
let name = move || match id().as_str() {
"alice" => "Alice",
"bob" => "Bob",
"steve" => "Steve",
_ => "User not found.",
};
view! {
<div class="contact-info">
<h4>{name}</h4>
<div class="tabs">
<A href="" exact=true>"Contact Info"</A>
<A href="conversations">"Conversations"</A>
</div>
// <Outlet/> here is the tabs that are nested
// underneath the /contacts/:id route
<Outlet/>
</div>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/16-router-fy4tjv?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -1,12 +1,12 @@
# The `<Form/>` Component
Links and forms sometimes seem completely unrelated. But, in fact, they work in very similar ways.
Links and forms sometimes seem completely unrelated. But in fact, they work in very similar ways.
In plain HTML, there are three ways to navigate to another page:
1. An `<a>` element that links to another page: Navigates to the URL in its `href` attribute with the `GET` HTTP method.
2. A `<form method="GET">`: Navigates to the URL in its `action` attribute with the `GET` HTTP method and the form data from its inputs encoded in the URL query string.
3. A `<form method="POST">`: Navigates to the URL in its `action` attribute with the `POST` HTTP method and the form data from its inputs encoded in the body of the request.
1. An `<a>` element that links to another page. Navigates to the URL in its `href` attribute with the `GET` HTTP method.
2. A `<form method="GET">`. Navigates to the URL in its `action` attribute with the `GET` HTTP method and the form data from its inputs encoded in the URL query string.
3. A `<form method="POST">`. Navigates to the URL in its `action` attribute with the `POST` HTTP method and the form data from its inputs encoded in the body of the request.
Since we have a client-side router, we can do client-side link navigations without reloading the page, i.e., without a full round-trip to the server and back. It makes sense that we can do client-side form navigations in the same way.
@@ -24,15 +24,15 @@ async fn fetch_results() {
}
#[component]
pub fn FormExample() -> impl IntoView {
pub fn FormExample(cx: Scope) -> impl IntoView {
// reactive access to URL query strings
let query = use_query_map();
let query = use_query_map(cx);
// search stored as ?q=
let search = move || query().get("q").cloned().unwrap_or_default();
// a resource driven by the search string
let search_results = create_resource(search, fetch_results);
let search_results = create_resource(cx, search, fetch_results);
view! {
view! { cx,
<Form method="GET" action="">
<input type="search" name="search" value=search/>
<input type="submit"/>
@@ -51,7 +51,7 @@ This is a great pattern. The data flow is extremely clear: all data flows from t
We can actually take it a step further and do something kind of clever:
```rust
view! {
view! { cx,
<Form method="GET" action="">
<input type="search" name="search" value=search
oninput="this.form.requestSubmit()"
@@ -62,119 +62,6 @@ view! {
Youll notice that this version drops the `Submit` button. Instead, we add an `oninput` attribute to the input. Note that this is _not_ `on:input`, which would listen for the `input` event and run some Rust code. Without the colon, `oninput` is the plain HTML attribute. So the string is actually a JavaScript string. `this.form` gives us the form the input is attached to. `requestSubmit()` fires the `submit` event on the `<form>`, which is caught by `<Form/>` just as if we had clicked a `Submit` button. Now the form will “navigate” on every keystroke or input to keep the URL (and therefore the search) perfectly in sync with the users input as they type.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/20-form-0-5-9g7v9p?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/16-router-forked-hrrt3h?file=%2Fsrc%2Fmain.rs)
<iframe src="https://codesandbox.io/p/sandbox/20-form-0-5-9g7v9p?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
use leptos_router::*;
#[component]
fn App() -> impl IntoView {
view! {
<Router>
<h1><code>"<Form/>"</code></h1>
<main>
<Routes>
<Route path="" view=FormExample/>
</Routes>
</main>
</Router>
}
}
#[component]
pub fn FormExample() -> impl IntoView {
// reactive access to URL query
let query = use_query_map();
let name = move || query().get("name").cloned().unwrap_or_default();
let number = move || query().get("number").cloned().unwrap_or_default();
let select = move || query().get("select").cloned().unwrap_or_default();
view! {
// read out the URL query strings
<table>
<tr>
<td><code>"name"</code></td>
<td>{name}</td>
</tr>
<tr>
<td><code>"number"</code></td>
<td>{number}</td>
</tr>
<tr>
<td><code>"select"</code></td>
<td>{select}</td>
</tr>
</table>
// <Form/> will navigate whenever submitted
<h2>"Manual Submission"</h2>
<Form method="GET" action="">
// input names determine query string key
<input type="text" name="name" value=name/>
<input type="number" name="number" value=number/>
<select name="select">
// `selected` will set which starts as selected
<option selected=move || select() == "A">
"A"
</option>
<option selected=move || select() == "B">
"B"
</option>
<option selected=move || select() == "C">
"C"
</option>
</select>
// submitting should cause a client-side
// navigation, not a full reload
<input type="submit"/>
</Form>
// This <Form/> uses some JavaScript to submit
// on every input
<h2>"Automatic Submission"</h2>
<Form method="GET" action="">
<input
type="text"
name="name"
value=name
// this oninput attribute will cause the
// form to submit on every input to the field
oninput="this.form.requestSubmit()"
/>
<input
type="number"
name="number"
value=number
oninput="this.form.requestSubmit()"
/>
<select name="select"
onchange="this.form.requestSubmit()"
>
<option selected=move || select() == "A">
"A"
</option>
<option selected=move || select() == "B">
"B"
</option>
<option selected=move || select() == "C">
"C"
</option>
</select>
// submitting should cause a client-side
// navigation, not a full reload
<input type="submit"/>
</Form>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/16-router-forked-hrrt3h?file=%2Fsrc%2Fmain.rs" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -4,10 +4,10 @@
Routing drives most websites. A router is the answer to the question, “Given this URL, what should appear on the page?”
A URL consists of many parts. For example, the URL `https://my-cool-blog.com/blog/search?q=Search#results` consists of
A URL consists of many parts. For example, the URL `https://leptos.dev/blog/search?q=Search#results` consists of
- a _scheme_: `https`
- a _domain_: `my-cool-blog.com`
- a _domain_: `leptos.dev`
- a **path**: `/blog/search`
- a **query** (or **search**): `?q=Search`
- a _hash_: `#results`

View File

@@ -31,8 +31,9 @@ pub async fn add_todo(title: String) -> Result<(), ServerFnError> {
}
#[component]
pub fn BusyButton() -> impl IntoView {
pub fn BusyButton(cx: Scope) -> impl IntoView {
view! {
cx,
<button on:click=move |_| {
spawn_local(async {
add_todo("So much to do!".to_string()).await;
@@ -42,6 +43,15 @@ pub fn BusyButton() -> impl IntoView {
</button>
}
}
// somewhere in main.rs
fn main() {
// ...
AddTodo::register();
// ...
}
```
Youll notice a couple things here right away:
@@ -65,22 +75,10 @@ move |_| {
There are a few things to note about the way you define a server function, too.
- Server functions are created by using the [`#[server]` macro](https://docs.rs/leptos_server/latest/leptos_server/index.html#server) to annotate a top-level function, which can be defined anywhere.
- We provide the macro a type name. The type name is used internally as a container to hold, serialize, and deserialize the arguments.
- We provide the macro a type name. The type name is used to register the server function (in `main.rs`), and its used internally as a container to hold, serialize, and deserialize the arguments.
- We provide the macro a path. This is a prefix for the path at which well mount a server function handler on our server. (See examples for [Actix](https://github.com/leptos-rs/leptos/blob/main/examples/todo_app_sqlite/src/main.rs#L44) and [Axum](https://github.com/leptos-rs/leptos/blob/598523cd9d0d775b017cb721e41ebae9349f01e2/examples/todo_app_sqlite_axum/src/main.rs#L51).)
- Youll need to have `serde` as a dependency with the `derive` featured enabled for the macro to work properly. You can easily add it to `Cargo.toml` with `cargo add serde --features=derive`.
## Server Function URL Prefixes
You can optionally define a specific URL prefix to be used in the definition of the server function.
This is done by providing an optional 2nd argument to the `#[server]` macro.
By default the URL prefix will be `/api`, if not specified.
Here are some examples:
```rust
#[server(AddTodo)] // will use the default URL prefix of `/api`
#[server(AddTodo, "/foo")] // will use the URL prefix of `/foo`
```
## Server Function Encodings
By default, the server function call is a `POST` request that serializes the arguments as URL-encoded form data in the body of the request. (This means that server functions can be called from HTML forms, which well see in a future chapter.) But there are a few other methods supported. Optionally, we can provide another argument to the `#[server]` macro to specify an alternate encoding:
@@ -108,29 +106,6 @@ In other words, you have two choices:
**But remember**: Leptos will handle all the details of this encoding and decoding for you. When you use a server function, it looks just like calling any other asynchronous function!
> **Why not `PUT` or `DELETE`? Why URL/form encoding, and not JSON?**
>
> These are reasonable questions. Much of the web is built on REST API patterns that encourage the use of semantic HTTP methods like `DELETE` to delete an item from a database, and many devs are accustomed to sending data to APIs in the JSON format.
>
> The reason we use `POST` or `GET` with URL-encoded data by default is the `<form>` support. For better or for worse, HTML forms dont support `PUT` or `DELETE`, and they dont support sending JSON. This means that if you use anything but a `GET` or `POST` request with URL-encoded data, it can only work once WASM has loaded. As well see [in a later chapter](../progressive_enhancement), this isnt always a great idea.
>
> The CBOR encoding is suported for historical reasons; an earlier version of server functions used a URL encoding that didnt support nested objects like structs or vectors as server function arguments, which CBOR did. But note that the CBOR forms encounter the same issue as `PUT`, `DELETE`, or JSON: they do not degrade gracefully if the WASM version of your app is not available.
## Server Functions Endpoint Paths
By default, a unique path will be generated. You can optionally define a specific endpoint path to be used in the URL. This is done by providing an optional 4th argument to the `#[server]` macro. Leptos will generate the complete path by concatenating the URL prefix (2nd argument) and the endpoint path (4th argument).
For example,
```rust
#[server(MyServerFnType, "/api", "Url", "hello")]
```
will generate a server function endpoint at `/api/hello` that accepts a POST request.
> **Can I use the same server function endpoint path with multiple encodings?**
>
> No. Different server functions must have unique paths. The `#[server]` macro automatically generates unique paths, but you need to be careful if you choose to specify the complete path manually, as the server looks up server functions by their path.
## An Important Note on Security
Server functions are a cool technology, but its very important to remember. **Server functions are not magic; theyre syntax sugar for defining a public API.** The _body_ of a server function is never made public; its just part of your server binary. But the server function is a publicly accessible API endpoint, and its return value is just a JSON or similar blob. You should _never_ return something sensitive from a server function.
@@ -139,7 +114,7 @@ Server functions are a cool technology, but its very important to remember. *
So far, everything Ive said is actually framework agnostic. (And in fact, the Leptos server function crate has been integrated into Dioxus as well!) Server functions are simply a way of defining a function-like RPC call that leans on Web standards like HTTP requests and URL encoding.
But in a way, they also provide the last missing primitive in our story so far. Because a server function is just a plain Rust async function, it integrates perfectly with the async Leptos primitives we discussed [earlier](https://leptos-rs.github.io/leptos/async/index.html). So you can easily integrate your server functions with the rest of your applications:
But in a way, they also provide the last missing primitive in our story so far. Because a server function is just a plain Rust async function, it integrates perfectly with the async Leptos primitives we discussed [earlier](../async/README.md). So you can easily integrate your server functions with the rest of your applications:
- Create **resources** that call the server function to load data from the server
- Read these resources under `<Suspense/>` or `<Transition/>` to enable streaming SSR and fallback states while data loads.

View File

@@ -1,87 +0,0 @@
# Extractors
The server functions we looked at in the last chapter showed how to run code on the server, and integrate it with the user interface youre rendering in the browser. But they didnt show you much about how to actually use your server to its full potential.
## Server Frameworks
We call Leptos a “full-stack” framework, but “full-stack” is always a misnomer (after all, it never means everything from the browser to your power company.) For us, “full stack” means that your Leptos app can run in the browser, and can run on the server, and can integrate the two, drawing together the unique features available in each; as weve seen in the book so far, a button click on the browser can drive a database read on the server, both written in the same Rust module. But Leptos itself doesnt provide the server (or the database, or the operating system, or the firmware, or the electrical cables...)
Instead, Leptos provides integrations for the two most popular Rust web server frameworks, Actix Web ([`leptos_actix`](https://docs.rs/leptos_actix/latest/leptos_actix/)) and Axum ([`leptos_axum`](https://docs.rs/leptos_axum/latest/leptos_axum/)). Weve built integrations with each servers router so that you can simply plug your Leptos app into an existing server with `.leptos_routes()`, and easily handle server function calls.
> If you havent seen our [Actix](https://github.com/leptos-rs/start) and [Axum](https://github.com/leptos-rs/start-axum) templates, nows a good time to check them out.
## Using Extractors
Both Actix and Axum handlers are built on the same powerful idea of **extractors**. Extractors “extract” typed data from an HTTP request, allowing you to access server-specific data easily.
Leptos provides `extract` helper functions to let you use these extractors directly in your server functions, with a convenient syntax very similar to handlers for each framework.
### Actix Extractors
The [`extract` function in `leptos_actix`](https://docs.rs/leptos_actix/latest/leptos_actix/fn.extract.html) takes a handler function as its argument. The handler follows similar rules to an Actix handler: it is an async function that receives arguments that will be extracted from the request and returns some value. The handler function receives that extracted data as its arguments, and can do further `async` work on them inside the body of the `async move` block. It returns whatever value you return back out into the server function.
```rust
#[server(ActixExtract, "/api")]
pub async fn actix_extract() -> Result<String, ServerFnError> {
use leptos_actix::extract;
use actix_web::dev::ConnectionInfo;
use actix_web::web::{Data, Query};
extract(
|search: Query<Search>, connection: ConnectionInfo| async move {
format!(
"search = {}\nconnection = {:?}",
search.q,
connection
)
},
)
.await
}
```
## Axum Extractors
The syntax for the [`leptos_axum::extract`](https://docs.rs/leptos_axum/latest/leptos_axum/fn.extract.html) function is very similar. (**Note**: This is available on the git main branch, but has not been released as of writing.) Note that Axum extractors return a `Result`, so youll need to add something to handle the error case.
```rust
#[server(AxumExtract, "/api")]
pub async fn axum_extract() -> Result<String, ServerFnError> {
use axum::{extract::Query, http::Method};
use leptos_axum::extract;
extract(|method: Method, res: Query<MyQuery>| async move {
format!("{method:?} and {}", res.q)
},
)
.await
.map_err(|e| ServerFnError::ServerError("Could not extract method and query...".to_string()))
}
```
These are relatively simple examples accessing basic data from the server. But you can use extractors to access things like headers, cookies, database connection pools, and more, using the exact same `extract()` pattern.
The Axum `extract` function only supports extractors for which the state is `()`. If you need an extractor that uses `State`, you should use [`extract_with_state`](https://docs.rs/leptos_axum/latest/leptos_axum/fn.extract_with_state.html). This requires you to provide the state. You can do this by extending the existing `LeptosOptions` state using the Axum `FromRef` pattern, which providing the state as context during render and server functions with custom handlers.
```rust
use axum::extract::FromRef;
/// Derive FromRef to allow multiple items in state, using Axums
/// SubStates pattern.
#[derive(FromRef, Debug, Clone)]
pub struct AppState{
pub leptos_options: LeptosOptions,
pub pool: SqlitePool
}
```
[Click here for an example of providing context in custom handlers](https://github.com/leptos-rs/leptos/blob/19ea6fae6aec2a493d79cc86612622d219e6eebb/examples/session_auth_axum/src/main.rs#L24-L44).
## A Note about Data-Loading Patterns
Because Actix and (especially) Axum are built on the idea of a single round-trip HTTP request and response, you typically run extractors near the “top” of your application (i.e., before you start rendering) and use the extracted data to determine how that should be rendered. Before you render a `<button>`, you load all the data your app could need. And any given route handler needs to know all the data that will need to be extracted by that route.
But Leptos integrates both the client and the server, and its important to be able to refresh small pieces of your UI with new data from the server without forcing a full reload of all the data. So Leptos likes to push data loading “down” in your application, as far towards the leaves of your user interface as possible. When you click a `<button>`, it can refresh just the data it needs. This is exactly what server functions are for: they give you granular access to data to be loaded and reloaded.
The `extract()` functions let you combine both models by using extractors in your server functions. You get access to the full power of route extractors, while decentralizing knowledge of what needs to be extracted down to your individual components. This makes it easier to refactor and reorganize routes: you dont need to specify all the data a route needs up front.

View File

@@ -1,73 +0,0 @@
# Responses and Redirects
Extractors provide an easy way to access request data inside server functions. Leptos also provides a way to modify the HTTP response, using the `ResponseOptions` type (see docs for [Actix](https://docs.rs/leptos_actix/latest/leptos_actix/struct.ResponseOptions.html) or [Axum](https://docs.rs/leptos_axum/latest/leptos_axum/struct.ResponseOptions.html)) types and the `redirect` helper function (see docs for [Actix](https://docs.rs/leptos_actix/latest/leptos_actix/fn.redirect.html) or [Axum](https://docs.rs/leptos_axum/latest/leptos_axum/fn.redirect.html)).
## `ResponseOptions`
`ResponseOptions` is provided via context during the initial server rendering response and during any subsequent server function call. It allows you to easily set the status code for the HTTP response, or to add headers to the HTTP response, e.g., to set cookies.
```rust
#[server(TeaAndCookies)]
pub async fn tea_and_cookies() -> Result<(), ServerFnError> {
use actix_web::{cookie::Cookie, http::header, http::header::HeaderValue};
use leptos_actix::ResponseOptions;
// pull ResponseOptions from context
let response = expect_context::<ResponseOptions>();
// set the HTTP status code
response.set_status(StatusCode::IM_A_TEAPOT);
// set a cookie in the HTTP response
let mut cookie = Cookie::build("biscuits", "yes").finish();
if let Ok(cookie) = HeaderValue::from_str(&cookie.to_string()) {
res.insert_header(header::SET_COOKIE, cookie);
}
}
```
## `redirect`
One common modification to an HTTP response is to redirect to another page. The Actix and Axum integrations provide a `redirect` function to make this easy to do. `redirect` simply sets an HTTP status code of `302 Found` and sets the `Location` header.
Heres a simplified example from our [`session_auth_axum` example](https://github.com/leptos-rs/leptos/blob/a5f73b441c079f9138102b3a7d8d4828f045448c/examples/session_auth_axum/src/auth.rs#L154-L181).
```rust
#[server(Login, "/api")]
pub async fn login(
username: String,
password: String,
remember: Option<String>,
) -> Result<(), ServerFnError> {
// pull the DB pool and auth provider from context
let pool = pool()?;
let auth = auth()?;
// check whether the user exists
let user: User = User::get_from_username(username, &pool)
.await
.ok_or_else(|| {
ServerFnError::ServerError("User does not exist.".into())
})?;
// check whether the user has provided the correct password
match verify(password, &user.password)? {
// if the password is correct...
true => {
// log the user in
auth.login_user(user.id);
auth.remember_user(remember.is_some());
// and redirect to the home page
leptos_axum::redirect("/");
Ok(())
}
// if not, return an error
false => Err(ServerFnError::ServerError(
"Password does not match.".to_string(),
)),
}
}
```
This server function can then be used from your application. This `redirect` works well with the progressively-enhanced `<ActionForm/>` component: without JS/WASM, the server response will redirect because of the status code and header. With JS/WASM, the `<ActionForm/>` will detect the redirect in the server function response, and use client-side navigation to redirect to the new page.

View File

@@ -8,12 +8,7 @@ If youve ever listened to streaming music or watched a video online, Im su
Let me say a little more about what I mean.
Leptos supports all the major ways of rendering HTML that includes asynchronous data:
1. [Synchronous Rendering](#synchronous-rendering)
1. [Async Rendering](#async-rendering)
1. [In-Order streaming](#in-order-streaming)
1. [Out-of-Order Streaming](#out-of-order-streaming) (and a partially-blocked variant)
Leptos supports all four different of these different ways to render HTML that includes asynchronous data.
## Synchronous Rendering
@@ -67,16 +62,6 @@ If youre using server-side rendering, the synchronous mode is almost never wh
- Able to show the fallback loading state and dynamically replace it, instead of showing blank sections for un-loaded data.
- _Cons_: Requires JavaScript to be enabled for suspended fragments to appear in correct order. (This small chunk of JS streamed down in a `<script>` tag alongside the `<template>` tag that contains the rendered `<Suspense/>` fragment, so it does not need to load any additional JS files.)
5. **Partially-blocked streaming**: “Partially-blocked” streaming is useful when you have multiple separate `<Suspense/>` components on the page. It is triggered by setting `ssr=SsrMode::PartiallyBlocked` on a route, and depending on blocking resources within the view. If one of the `<Suspense/>` components reads from one or more “blocking resources” (see below), the fallback will not be sent; rather, the server will wait until that `<Suspense/>` has resolved and then replace the fallback with the resolved fragment on the server, which means that it is included in the initial HTML response and appears even if JavaScript is disabled or not supported. Other `<Suspense/>` stream in out of order, similar to the `SsrMode::OutOfOrder` default.
This is useful when you have multiple `<Suspense/>` on the page, and one is more important than the other: think of a blog post and comments, or product information and reviews. It is _not_ useful if theres only one `<Suspense/>`, or if every `<Suspense/>` reads from blocking resources. In those cases it is a slower form of `async` rendering.
- _Pros_: Works if JavaScript is disabled or not supported on the users device.
- _Cons_
- Slower initial response time than out-of-order.
- Marginally overall response due to additional work on the server.
- No fallback state shown.
## Using SSR Modes
Because it offers the best blend of performance characteristics, Leptos defaults to out-of-order streaming. But its really simple to opt into these different modes. You do it by adding an `ssr` property onto one or more of your `<Route/>` components, like in the [`ssr_modes` example](https://github.com/leptos-rs/leptos/blob/main/examples/ssr_modes/src/app.rs).
@@ -84,13 +69,13 @@ Because it offers the best blend of performance characteristics, Leptos defaults
```rust
<Routes>
// Well load the home page with out-of-order streaming and <Suspense/>
<Route path="" view=HomePage/>
<Route path="" view=|cx| view! { cx, <HomePage/> }/>
// We'll load the posts with async rendering, so they can set
// the title and metadata *after* loading the data
<Route
path="/post/:id"
view=Post
view=|cx| view! { cx, <Post/> }
ssr=SsrMode::Async
/>
</Routes>
@@ -110,14 +95,14 @@ With blocking resources, I can do something like this:
```rust
#[component]
pub fn BlogPost() -> impl IntoView {
let post_data = create_blocking_resource(/* load blog post */);
let comment_data = create_resource(/* load blog post */);
view! {
pub fn BlogPost(cx: Scope) -> impl IntoView {
let post_data = create_blocking_resource(cx, /* load blog post */);
let comment_data = create_resource(cx, /* load blog post */);
view! { cx,
<Suspense fallback=|| ()>
{move || {
post_data.with(|data| {
view! {
post_data.with(cx, |data| {
view! { cx,
<Title text=data.title/>
<Meta name="description" content=data.excerpt/>
<article>
@@ -134,23 +119,4 @@ pub fn BlogPost() -> impl IntoView {
}
```
The first `<Suspense/>`, with the body of the blog post, will block my HTML stream, because it reads from a blocking resource. Meta tags and other head elements awaiting the blocking resource will be rendered before the stream is sent.
Combined with the following route definition, which uses `SsrMode::PartiallyBlocked`, the blocking resource will be fully rendered on the server side, making it accessible to users who disable WebAssembly or JavaScript.
```rust
<Routes>
// Well load the home page with out-of-order streaming and <Suspense/>
<Route path="" view=HomePage/>
// We'll load the posts with async rendering, so they can set
// the title and metadata *after* loading the data
<Route
path="/post/:id"
view=Post
ssr=SsrMode::PartiallyBlocked
/>
</Routes>
```
The second `<Suspense/>`, with the comments, will not block the stream. Blocking resources gave me exactly the power and granularity I needed to optimize my page for SEO and user experience.
The first `<Suspense/>`, with the body of the blog post, will block my HTML stream, because it reads from a blocking resource. The second `<Suspense/>`, with the comments, will not block the stream. Blocking resources gave me exactly the power and granularity I needed to optimize my page for SEO and user experience.

View File

@@ -8,8 +8,8 @@ Put a log somewhere in your root component. (I usually call mine `<App/>`, but a
```rust
#[component]
pub fn App() -> impl IntoView {
logging::log!("where do I run?");
pub fn App(cx: Scope) -> impl IntoView {
leptos::log!("where do I run?");
// ... whatever
}
```
@@ -57,15 +57,15 @@ One way to create a bug is by creating a mismatch between the HTML thats sent
```rust
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
let data = if cfg!(target_arch = "wasm32") {
vec![0, 1, 2]
} else {
vec![]
};
data.into_iter()
.map(|value| view! { <span>{value}</span> })
.collect_view()
.map(|value| view! { cx, <span>{value}</span> })
.collect_view(cx)
}
```
@@ -74,11 +74,11 @@ In other words, if this is being compiled to WASM, it has three items; otherwise
When I load the page in the browser, I see nothing. If I open the console I see a bunch of warnings:
```
element with id 0-3 not found, ignoring it for hydration
element with id 0-4 not found, ignoring it for hydration
element with id 0-5 not found, ignoring it for hydration
component with id _0-6c not found, ignoring it for hydration
component with id _0-6o not found, ignoring it for hydration
element with id 0-0-1 not found, ignoring it for hydration
element with id 0-0-2 not found, ignoring it for hydration
element with id 0-0-3 not found, ignoring it for hydration
component with id _0-0-4c not found, ignoring it for hydration
component with id _0-0-4o not found, ignoring it for hydration
```
The WASM version of your app, running in the browser, expects to find three items; but the HTML has none.
@@ -87,19 +87,6 @@ The WASM version of your app, running in the browser, expects to find three item
Its pretty rare that you do this intentionally, but it could happen from somehow running different logic on the server and in the browser. If youre seeing warnings like this and you dont think its your fault, its much more likely that its a bug with `<Suspense/>` or something. Feel free to go ahead and open an [issue](https://github.com/leptos-rs/leptos/issues) or [discussion](https://github.com/leptos-rs/leptos/discussions) on GitHub for help.
#### Solution
You can simply tell the effect to wait a tick before updating the signal, by using something like `request_animation_frame`, which will set a short timeout and then update the signal before the next frame.
```rust
create_effect(move |_| {
// do something like reading from localStorage
request_animation_frame(move || set_loaded(true));
});
```
This allows the browser to hydrate with the correct, matching state (`loaded` is `false` when it reaches the view), then immediately update it to `true` once hydration is complete.
### Not all client code can run on the server
Imagine you happily import a dependency like `gloo-net` that youve been used to using to make requests in the browser, and use it in a `create_resource` in a server-rendered app.
@@ -126,10 +113,10 @@ For example, say that I want to store something in the browsers `localStorage
```rust
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
use gloo_storage::Storage;
let storage = gloo_storage::LocalStorage::raw();
logging::log!("{storage:?}");
leptos::log!("{storage:?}");
}
```
@@ -139,11 +126,11 @@ But if I wrap it in an effect...
```rust
#[component]
pub fn App() -> impl IntoView {
pub fn App(cx: Scope) -> impl IntoView {
use gloo_storage::Storage;
create_effect(move |_| {
create_effect(cx, move |_| {
let storage = gloo_storage::LocalStorage::raw();
logging::log!("{storage:?}");
leptos::log!("{storage:?}");
});
}
```

View File

@@ -14,8 +14,8 @@ For example, instead of embedding logic in a component directly like this:
```rust
#[component]
pub fn TodoApp() -> impl IntoView {
let (todos, set_todos) = create_signal(vec![Todo { /* ... */ }]);
pub fn TodoApp(cx: Scope) -> impl IntoView {
let (todos, set_todos) = create_signal(cx, vec![Todo { /* ... */ }]);
// ⚠️ this is hard to test because it's embedded in the component
let num_remaining = move || todos.with(|todos| {
todos.iter().filter(|todo| !todo.completed).sum()
@@ -37,14 +37,14 @@ impl Todos {
#[cfg(test)]
mod tests {
#[test]
fn test_remaining() {
fn test_remaining {
// ...
}
}
#[component]
pub fn TodoApp() -> impl IntoView {
let (todos, set_todos) = create_signal(Todos(vec![Todo { /* ... */ }]));
pub fn TodoApp(cx: Scope) -> impl IntoView {
let (todos, set_todos) = create_signal(cx, Todos(vec![Todo { /* ... */ }]));
// ✅ this has a test associated with it
let num_remaining = move || todos.with(Todos::num_remaining);
}
@@ -53,48 +53,98 @@ pub fn TodoApp() -> impl IntoView {
In general, the less of your logic is wrapped into your components themselves, the
more idiomatic your code will feel and the easier it will be to test.
## 2. Test components with end-to-end (`e2e`) testing
## 2. Test components with `wasm-bindgen-test`
Our [`examples`](https://github.com/leptos-rs/leptos/tree/main/examples) directory has several examples with extensive end-to-end testing, using different testing tools.
[`wasm-bindgen-test`](https://crates.io/crates/wasm-bindgen-test) is a great utility
for integrating or end-to-end testing WebAssembly apps in a headless browser.
The easiest way to see how to use these is to take a look at the test examples themselves:
To use this testing utility, you need to add `wasm-bindgen-test` to your `Cargo.toml`:
### `wasm-bindgen-test` with [`counter`](https://github.com/leptos-rs/leptos/blob/main/examples/counter/tests/web.rs)
```toml
[dev-dependencies]
wasm-bindgen-test = "0.3.0"
```
This is a fairly simple manual testing setup that uses the [`wasm-pack test`](https://rustwasm.github.io/wasm-pack/book/commands/test.html) command.
You should create tests in a separate `tests` directory. You can then run your tests in the browser of your choice:
#### Sample Test
```bash
wasm-pack test --firefox
```
````rust
> To see the full setup, check out the tests for the [`counter`](https://github.com/leptos-rs/leptos/tree/main/examples/counter) example.
### Writing Your Tests
Most tests will involve some combination of vanilla DOM manipulation and comparison to a `view`. For example, heres a test [for the
`counter` example](https://github.com/leptos-rs/leptos/blob/main/examples/counter/tests/mod.rs).
First, we set up the testing environment.
```rust
use wasm_bindgen_test::*;
use counter::*;
use leptos::*;
use web_sys::HtmlElement;
// tell the test runner to run tests in the browser
wasm_bindgen_test_configure!(run_in_browser);
```
Im going to create a simpler wrapper for each test case, and mount it there.
This makes it easy to encapsulate the test results.
```rust
// like marking a regular test with #[test]
#[wasm_bindgen_test]
fn clear() {
let document = leptos::document();
let test_wrapper = document.create_element("section").unwrap();
let _ = document.body().unwrap().append_child(&test_wrapper);
document.body().unwrap().append_child(&test_wrapper);
// start by rendering our counter and mounting it to the DOM
// note that we start at the initial value of 10
mount_to(
test_wrapper.clone().unchecked_into(),
|| view! { <SimpleCounter initial_value=10 step=1/> },
|cx| view! { cx, <SimpleCounter initial_value=10 step=1/> },
);
}
```
let div = test_wrapper.query_selector("div").unwrap().unwrap();
let clear = test_wrapper
.query_selector("button")
.unwrap()
.unwrap()
.unchecked_into::<web_sys::HtmlElement>();
Well use some manual DOM operations to grab the `<div>` that wraps
the whole component, as well as the `clear` button.
clear.click();
```rust
// now we extract the buttons by iterating over the DOM
// this would be easier if they had IDs
let div = test_wrapper.query_selector("div").unwrap().unwrap();
let clear = test_wrapper
.query_selector("button")
.unwrap()
.unwrap()
.unchecked_into::<web_sys::HtmlElement>();
```
Now we can use ordinary DOM APIs to simulate user interaction.
```rust
// now let's click the `clear` button
clear.click();
```
You can test individual DOM element attributes or text node values. Sometimes
I like to test the whole view at once. We can do this by testing the elements
`outerHTML` against our expectations.
```rust
assert_eq!(
div.outer_html(),
// here we spawn a mini reactive system to render the test case
run_scope(create_runtime(), || {
run_scope(create_runtime(), |cx| {
// it's as if we're creating it with a value of 0, right?
let (value, set_value) = create_signal(0);
let (value, set_value) = create_signal(cx, 0);
// we can remove the event listeners because they're not rendered to HTML
view! {
view! { cx,
<div>
<button>"Clear"</button>
<button>"-1"</button>
@@ -107,113 +157,24 @@ assert_eq!(
.outer_html()
})
);
}
````
### [`wasm-bindgen-test` with `counters_stable`](https://github.com/leptos-rs/leptos/tree/main/examples/counters_stable/tests/web)
This more developed test suite uses a system of fixtures to refactor the manual DOM manipulation of the `counter` tests and easily test a wide range of cases.
#### Sample Test
```rust
use super::*;
use crate::counters_page as ui;
use pretty_assertions::assert_eq;
#[wasm_bindgen_test]
fn should_increase_the_total_count() {
// Given
ui::view_counters();
ui::add_counter();
// When
ui::increment_counter(1);
ui::increment_counter(1);
ui::increment_counter(1);
// Then
assert_eq!(ui::total(), 3);
}
```
### [Playwright with `counters_stable`](https://github.com/leptos-rs/leptos/tree/main/examples/counters_stable/e2e)
That test involved us manually replicating the `view` thats inside the component.
There's actually an easier way to do this... We can just test against a `<SimpleCounter/>`
with the initial value `0`. This is where our wrapping element comes in: Ill just test
the wrappers `innerHTML` against another comparison case.
These tests use the common JavaScript testing tool Playwright to run end-to-end tests on the same example, using a library and testing approach familiar to may who have done frontend development before.
#### Sample Test
```js
import { test, expect } from "@playwright/test";
import { CountersPage } from "./fixtures/counters_page";
test.describe("Increment Count", () => {
test("should increase the total count", async ({ page }) => {
const ui = new CountersPage(page);
await ui.goto();
await ui.addCounter();
await ui.incrementCount();
await ui.incrementCount();
await ui.incrementCount();
await expect(ui.total).toHaveText("3");
});
```rust
assert_eq!(test_wrapper.inner_html(), {
let comparison_wrapper = document.create_element("section").unwrap();
leptos::mount_to(
comparison_wrapper.clone().unchecked_into(),
|cx| view! { cx, <SimpleCounter initial_value=0 step=1/>},
);
comparison_wrapper.inner_html()
});
```
### [Gherkin/Cucumber Tests with `todo_app_sqlite`](https://github.com/leptos-rs/leptos/blob/main/examples/todo_app_sqlite/e2e/README.md)
This is only a very limited introduction to testing. But I hope its useful as you begin to build applications.
You can integrate any testing tool youd like into this flow. This example uses Cucumber, a testing framework based on natural language.
```
@add_todo
Feature: Add Todo
Background:
Given I see the app
@add_todo-see
Scenario: Should see the todo
Given I set the todo as Buy Bread
When I click the Add button
Then I see the todo named Buy Bread
# @allow.skipped
@add_todo-style
Scenario: Should see the pending todo
When I add a todo as Buy Oranges
Then I see the pending todo
```
The definitions for these actions are defined in Rust code.
```rust
use crate::fixtures::{action, world::AppWorld};
use anyhow::{Ok, Result};
use cucumber::{given, when};
#[given("I see the app")]
#[when("I open the app")]
async fn i_open_the_app(world: &mut AppWorld) -> Result<()> {
let client = &world.client;
action::goto_path(client, "").await?;
Ok(())
}
#[given(regex = "^I add a todo as (.*)$")]
#[when(regex = "^I add a todo as (.*)$")]
async fn i_add_a_todo_titled(world: &mut AppWorld, text: String) -> Result<()> {
let client = &world.client;
action::add_todo(client, text.as_str()).await?;
Ok(())
}
// etc.
```
### Learning More
Feel free to check out the CI setup in the Leptos repo to learn more about how to use these tools in your own application. All of these testing methods are run regularly against actual Leptos example apps.
> For more, see [the testing section of the `wasm-bindgen` guide](https://rustwasm.github.io/wasm-bindgen/wasm-bindgen-test/index.html#testing-on-wasm32-unknown-unknown-with-wasm-bindgen-test).

View File

@@ -13,7 +13,7 @@ DOM, with self-contained, defined behavior. Unlike HTML elements, they are in
```rust
fn main() {
leptos::mount_to_body(|| view! { <App/> })
leptos::mount_to_body(|cx| view! { cx, <App/> })
}
```
@@ -22,13 +22,13 @@ Ill give you the whole thing up front, then walk through it line by line.
```rust
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
fn App(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
view! {
view! { cx,
<button
on:click=move |_| {
set_count(3);
set_count.update(|n| *n += 1);
}
>
"Click me: "
@@ -49,17 +49,18 @@ used as a component in your Leptos application. Well see some of the other fe
this macro in a couple chapters.
```rust
fn App() -> impl IntoView
fn App(cx: Scope) -> impl IntoView
```
Every component is a function with the following characteristics
1. It takes zero or more arguments of any type.
2. It returns `impl IntoView`, which is an opaque type that includes
1. It takes a reactive [`Scope`](https://docs.rs/leptos/latest/leptos/struct.Scope.html)
as its first argument. This `Scope` is our entrypoint into the reactive system.
By convention, its usually named `cx`.
2. You can include other arguments, which will be available as component “props.”
3. Component functions return `impl IntoView`, which is an opaque type that includes
anything you could return from a Leptos `view`.
> Component function arguments are gathered together into a single props struct which is built by the `view` macro as needed.
## The Component Body
The body of the component function is a set-up function that runs once, not a
@@ -68,7 +69,7 @@ few reactive variables, define any side effects that run in response to those va
changing, and describe the user interface.
```rust
let (count, set_count) = create_signal(0);
let (count, set_count) = create_signal(cx, 0);
```
[`create_signal`](https://docs.rs/leptos/latest/leptos/fn.create_signal.html)
@@ -77,19 +78,19 @@ This returns a `(getter, setter)` tuple. To access the current value, youll
use `count.get()` (or, on `nightly` Rust, the shorthand `count()`). To set the
current value, youll call `set_count.set(...)` (or `set_count(...)`).
> `.get()` clones the value and `.set()` overwrites it. In many cases, its more efficient to use `.with()` or `.update()`; check out the docs for [`ReadSignal`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html) and [`WriteSignal`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html) if youd like to learn more about those trade-offs at this point.
> `.get()` clones the value and `.set()` overwrites it. In many cases, its more
> efficient to use `.with()` or `.update()`; check out the docs for [`ReadSignal`](https://docs.rs/leptos/latest/leptos/struct.ReadSignal.html) and [`WriteSignal`](https://docs.rs/leptos/latest/leptos/struct.WriteSignal.html) if youd like to learn more about those trade-offs at this point.
## The View
Leptos defines user interfaces using a JSX-like format via the [`view`](https://docs.rs/leptos/latest/leptos/macro.view.html) macro.
```rust
view! {
view! { cx,
<button
// define an event listener with on:
on:click=move |_| {
// on stable, this is set_count.set(3);
set_count(3);
set_count.update(|n| *n += 1);
}
>
// text nodes are wrapped in quotation marks
@@ -126,7 +127,7 @@ Leptos with `nightly` Rust, signals are already functions, so the closure is unn
As a result, you can write a simpler view:
```rust
view! {
view! { cx,
<button /* ... */>
"Click me: "
// identical to {move || count.get()}
@@ -138,88 +139,14 @@ view! {
Remember—and this is _very important_—only functions are reactive. This means that
`{count}` and `{count()}` do very different things in your view. `{count}` passes
in a function, telling the framework to update the view every time `count` changes.
`{count()}` accesses the value of `count` once, and passes an `i32` into the view,
`{count()}` access the value of `count` once, and passes an `i32` into the view,
rendering it once, unreactively. You can see the difference in the CodeSandbox below!
Lets make one final change. `set_count(3)` is a pretty useless thing for a click handler to do. Lets replace “set this value to 3” with “increment this value by 1”:
```rust
move |_| {
set_count.update(|n| *n += 1);
}
```
You can see here that while `set_count` just sets the value, `set_count.update()` gives us a mutable reference and mutates the value in place. Either one will trigger a reactive update in our UI.
> Throughout this tutorial, well use CodeSandbox to show interactive examples. To
> show the browser in the sandbox, you may need to click `Add DevTools >
Other Previews > 8080.` Hover over any of the variables to show Rust-Analyzer details
> and docs for whats going on. Feel free to fork the examples to play with them yourself!
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/1-basic-component-3d74p3?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/1-basic-component-3d74p3?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A31%2C%22endLineNumber%22%3A19%2C%22startColumn%22%3A31%2C%22startLineNumber%22%3A19%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/1-basic-component-3d74p3?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
// The #[component] macro marks a function as a reusable component
// Components are the building blocks of your user interface
// They define a reusable unit of behavior
#[component]
fn App() -> impl IntoView {
// here we create a reactive signal
// and get a (getter, setter) pair
// signals are the basic unit of change in the framework
// we'll talk more about them later
let (count, set_count) = create_signal(0);
// the `view` macro is how we define the user interface
// it uses an HTML-like format that can accept certain Rust values
view! {
<button
// on:click will run whenever the `click` event fires
// every event handler is defined as `on:{eventname}`
// we're able to move `set_count` into the closure
// because signals are Copy and 'static
on:click=move |_| {
set_count.update(|n| *n += 1);
}
>
// text nodes in RSX should be wrapped in quotes,
// like a normal Rust string
"Click me"
</button>
<p>
<strong>"Reactive: "</strong>
// you can insert Rust expressions as values in the DOM
// by wrapping them in curly braces
// if you pass in a function, it will reactively update
{move || count.get()}
</p>
<p>
<strong>"Reactive shorthand: "</strong>
// signals are functions, so we can remove the wrapping closure
{count}
</p>
<p>
<strong>"Not reactive: "</strong>
// NOTE: if you write {count()}, this will *not* be reactive
// it simply gets the value of count once
{count()}
</p>
}
}
// This `main` function is the entry point into the app
// It just mounts our component to the <body>
// Because we defined it as `fn App`, we can now use it in a
// template as <App/>
fn main() {
leptos::mount_to_body(|| view! { <App/> })
}
```
<iframe src="https://codesandbox.io/p/sandbox/1-basic-component-3d74p3?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A31%2C%22endLineNumber%22%3A19%2C%22startColumn%22%3A31%2C%22startLineNumber%22%3A19%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -12,10 +12,10 @@ increment a counter.
```rust
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
fn App(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
view! {
view! { cx,
<button
on:click=move |_| {
set_count.update(|n| *n += 1);
@@ -73,9 +73,9 @@ class=("button-20", move || count() % 2 == 1)
Individual CSS properties can be directly updated with a similar `style:` syntax.
```rust
let (x, set_x) = create_signal(0);
let (y, set_y) = create_signal(0);
view! {
let (x, set_x) = create_signal(cx, 0);
let (y, set_y) = create_signal(cx, 0);
view! { cx,
<div
style="position: absolute"
style:left=move || format!("{}px", x() + 100)
@@ -144,119 +144,11 @@ let double_count = move || count() * 2;
Derived signals let you create reactive computed values that can be used in multiple
places in your application with minimal overhead.
Note: Using a derived signal like this means that the calculation runs once per
signal change (when `count()` changes) and once per place we access `double_count`;
in other words, twice. This is a very cheap calculation, so thats fine.
Well look at memos in a later chapter, which re designed to solve this problem
for expensive calculations.
> Note: Using a derived signal like this means that the calculation runs once per
> signal change per place we access `double_count`; in other words, twice. This is a
> very cheap calculation, so thats fine. Well look at memos in a later chapter, which
> are designed to solve this problem for expensive calculations.
> #### Advanced Topic: Injecting Raw HTML
>
> The `view` macro provides support for an additional attribute, `inner_html`, which
> can be used to directly set the HTML contents of any element, wiping out any other
> children youve given it. Note that this does _not_ escape the HTML you provide. You
> should make sure that it only contains trusted input or that any HTML entities are
> escaped, to prevent cross-site scripting (XSS) attacks.
>
> ```rust
> let html = "<p>This HTML will be injected.</p>";
> view! {
> <div inner_html=html/>
> }
> ```
>
> [Click here for the full `view` macros docs](https://docs.rs/leptos/latest/leptos/macro.view.html).
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/2-dynamic-attribute-pqyvzl?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/2-dynamic-attributes-0-5-lwdrpm?file=%2Fsrc%2Fmain.rs%3A1%2C1)
<iframe src="https://codesandbox.io/p/sandbox/2-dynamic-attributes-0-5-lwdrpm?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>Code Sandbox Source</summary>
```rust
use leptos::*;
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
// a "derived signal" is a function that accesses other signals
// we can use this to create reactive values that depend on the
// values of one or more other signals
let double_count = move || count() * 2;
view! {
<button
on:click=move |_| {
set_count.update(|n| *n += 1);
}
// the class: syntax reactively updates a single class
// here, we'll set the `red` class when `count` is odd
class:red=move || count() % 2 == 1
>
"Click me"
</button>
// NOTE: self-closing tags like <br> need an explicit /
<br/>
// We'll update this progress bar every time `count` changes
<progress
// static attributes work as in HTML
max="50"
// passing a function to an attribute
// reactively sets that attribute
// signals are functions, so this <=> `move || count.get()`
value=count
>
</progress>
<br/>
// This progress bar will use `double_count`
// so it should move twice as fast!
<progress
max="50"
// derived signals are functions, so they can also
// reactive update the DOM
value=double_count
>
</progress>
<p>"Count: " {count}</p>
<p>"Double Count: " {double_count}</p>
}
}
fn main() {
leptos::mount_to_body(App)
}
// passing a function to an attribute
// reactively sets that attribute
// signals are functions, so this <=> `move || count.get()`
value=count
>
</progress>
<br/>
// This progress bar will use `double_count`
// so it should move twice as fast!
<progress
max="50"
// derived signals are functions, so they can also
// reactive update the DOM
value=double_count
>
</progress>
<p>"Count: " {count}</p>
<p>"Double Count: " {double_count}</p>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/2-dynamic-attribute-pqyvzl?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -12,7 +12,7 @@ per click.
You _could_ do this by just creating two `<progress>` elements:
```rust
let (count, set_count) = create_signal(0);
let (count, set_count) = create_signal(cx, 0);
let double_count = move || count() * 2;
view! {
@@ -35,8 +35,10 @@ Instead, lets create a `<ProgressBar/>` component.
```rust
#[component]
fn ProgressBar() -> impl IntoView {
view! {
fn ProgressBar(
cx: Scope
) -> impl IntoView {
view! { cx,
<progress
max="50"
// hmm... where will we get this from?
@@ -62,9 +64,10 @@ In Leptos, you define props by giving additional arguments to the component func
```rust
#[component]
fn ProgressBar(
cx: Scope,
progress: ReadSignal<i32>
) -> impl IntoView {
view! {
view! { cx,
<progress
max="50"
// now this works
@@ -78,9 +81,9 @@ Now we can use our component in the main `<App/>` components view.
```rust
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
view! {
fn App(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
view! { cx,
<button on:click=move |_| { set_count.update(|n| *n += 1); }>
"Click me"
</button>
@@ -95,6 +98,18 @@ notice that you can easily tell the difference between an element and a componen
because components always have `PascalCase` names. You pass the `progress` prop
in as if it were an HTML element attribute. Simple.
> ### Important Note
>
> For every `Component`, Leptos generates a corresponding `ComponentProps` type. This
> is what allows us to have named props, when Rust does not have named function parameters.
> If youre defining a component in one module and importing it into another, make
> sure you include this `ComponentProps` type:
>
> `use progress_bar::{ProgressBar, ProgressBarProps};`
>
> **Note**: This is still true as of `0.2.5`, but the requirement has been removed on `main`
> and will not apply to later versions.
### Reactive and Static Props
Youll notice that throughout this example, `progress` takes a reactive
@@ -115,13 +130,14 @@ argument to the component function with `#[prop(optional)]`.
```rust
#[component]
fn ProgressBar(
cx: Scope,
// mark this prop optional
// you can specify it or not when you use <ProgressBar/>
#[prop(optional)]
max: u16,
progress: ReadSignal<i32>
) -> impl IntoView {
view! {
view! { cx,
<progress
max=max
value=progress
@@ -145,11 +161,12 @@ with `#[prop(default = ...)`.
```rust
#[component]
fn ProgressBar(
cx: Scope,
#[prop(default = 100)]
max: u16,
progress: ReadSignal<i32>
) -> impl IntoView {
view! {
view! { cx,
<progress
max=max
value=progress
@@ -166,11 +183,11 @@ as the `progress` prop on another `<ProgressBar/>`.
```rust
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
fn App(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
let double_count = move || count() * 2;
view! {
view! { cx,
<button on:click=move |_| { set_count.update(|n| *n += 1); }>
"Click me"
</button>
@@ -194,6 +211,7 @@ implement the trait `Fn() -> i32`. So you could use a generic component:
```rust
#[component]
fn ProgressBar<F>(
cx: Scope,
#[prop(default = 100)]
max: u16,
progress: F
@@ -201,7 +219,7 @@ fn ProgressBar<F>(
where
F: Fn() -> i32 + 'static,
{
view! {
view! { cx,
<progress
max=max
value=progress
@@ -213,24 +231,9 @@ where
This is a perfectly reasonable way to write this component: `progress` now takes
any value that implements this `Fn()` trait.
This generic can also be specified inline:
```rust
#[component]
fn ProgressBar<F: Fn() -> i32 + 'static>(
#[prop(default = 100)] max: u16,
progress: F,
) -> impl IntoView {
view! {
<progress
max=max
value=progress
/>
}
}
```
> Note that generic component props _cant_ be specified with an `impl` yet (`progress: impl Fn() -> i32 + 'static,`), in part because theyre actually used to generate a `struct ProgressBarProps`, and struct fields cannot be `impl` types. The `#[component]` macro may be further improved in the future to allow inline `impl` generic props.
> Note that generic component props _cannot_ be specified inline (as `<F: Fn() -> i32>`)
> or as `progress: impl Fn() -> i32 + 'static,`, in part because theyre actually used to generate
> a `struct ProgressBarProps`, and struct fields cannot be `impl` types.
### `into` Props
@@ -248,13 +251,14 @@ reactive value.
```rust
#[component]
fn ProgressBar(
cx: Scope,
#[prop(default = 100)]
max: u16,
#[prop(into)]
progress: Signal<i32>
) -> impl IntoView
{
view! {
view! { cx,
<progress
max=max
value=progress
@@ -263,95 +267,22 @@ fn ProgressBar(
}
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
fn App(cx: Scope) -> impl IntoView {
let (count, set_count) = create_signal(cx, 0);
let double_count = move || count() * 2;
view! {
view! { cx,
<button on:click=move |_| { set_count.update(|n| *n += 1); }>
"Click me"
</button>
// .into() converts `ReadSignal` to `Signal`
<ProgressBar progress=count/>
// use `Signal::derive()` to wrap a derived signal
<ProgressBar progress=Signal::derive(double_count)/>
<ProgressBar progress=Signal::derive(cx, double_count)/>
}
}
```
### Optional Generic Props
Note that you cant specify optional generic props for a component. Lets see what would happen if you try:
```rust,compile_fail
#[component]
fn ProgressBar<F: Fn() -> i32 + 'static>(
#[prop(optional)] progress: Option<F>,
) -> impl IntoView {
progress.map(|progress| {
view! {
<progress
max=100
value=progress
/>
}
})
}
#[component]
pub fn App() -> impl IntoView {
view! {
<ProgressBar/>
}
}
```
Rust helpfully gives the error
```
xx | <ProgressBar/>
| ^^^^^^^^^^^ cannot infer type of the type parameter `F` declared on the function `ProgressBar`
|
help: consider specifying the generic argument
|
xx | <ProgressBar::<F>/>
| +++++
```
There are just two problems:
1. Leptoss view macro doesnt support specifying a generic on a component with this turbofish syntax.
2. Even if you could, specifying the correct type here is not possible; closures and functions in general are unnameable types. The compiler can display them with a shorthand, but you cant specify them.
However, you can get around this by providing a concrete type using `Box<dyn _>` or `&dyn _`:
```rust
#[component]
fn ProgressBar(
#[prop(optional)] progress: Option<Box<dyn Fn() -> i32>>,
) -> impl IntoView {
progress.map(|progress| {
view! {
<progress
max=100
value=progress
/>
}
})
}
#[component]
pub fn App() -> impl IntoView {
view! {
<ProgressBar/>
}
}
```
Because the Rust compiler now knows the concrete type of the prop, and therefore its size in memory even in the `None` case, this compiles fine.
> In this particular case, `&dyn Fn() -> i32` will cause lifetime issues, but in other cases, it may be a possibility.
## Documenting Components
This is one of the least essential but most important sections of this book.
@@ -366,6 +297,7 @@ component function, and each one of the props:
/// Shows progress toward a goal.
#[component]
fn ProgressBar(
cx: Scope,
/// The maximum value of the progress bar.
#[prop(default = 100)]
max: u16,
@@ -386,96 +318,6 @@ type, and each of the fields used to add props. It can be a little hard to
understand how powerful this is until you hover over the component name or props
and see the power of the `#[component]` macro combined with rust-analyzer here.
> #### Advanced Topic: `#[component(transparent)]`
>
> All Leptos components return `-> impl IntoView`. Some, though, need to return
> some data directly without any additional wrapping. These can be marked with
> `#[component(transparent)]`, in which case they return exactly the value they
> return, without the rendering system transforming them in any way.
>
> This is mostly used in two situations:
>
> 1. Creating wrappers around `<Suspense/>` or `<Transition/>`, which return a
> transparent suspense structure to integrate with SSR and hydration properly.
> 2. Refactoring `<Route/>` definitions for `leptos_router` out into separate
> components, because `<Route/>` is a transparent component that returns a
> `RouteDefinition` struct rather than a view.
>
> In general, you should not need to use transparent components unless you are
> creating custom wrapping components that fall into one of these two categories.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/3-components-50t2e7?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A7%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A7%7D%5D)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/3-components-0-5-5vvl69?file=%2Fsrc%2Fmain.rs%3A1%2C1)
<iframe src="https://codesandbox.io/p/sandbox/3-components-0-5-5vvl69?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
// Composing different components together is how we build
// user interfaces. Here, we'll define a resuable <ProgressBar/>.
// You'll see how doc comments can be used to document components
// and their properties.
/// Shows progress toward a goal.
#[component]
fn ProgressBar(
// Marks this as an optional prop. It will default to the default
// value of its type, i.e., 0.
#[prop(default = 100)]
/// The maximum value of the progress bar.
max: u16,
// Will run `.into()` on the value passed into the prop.
#[prop(into)]
// `Signal<T>` is a wrapper for several reactive types.
// It can be helpful in component APIs like this, where we
// might want to take any kind of reactive value
/// How much progress should be displayed.
progress: Signal<i32>,
) -> impl IntoView {
view! {
<progress
max={max}
value=progress
/>
<br/>
}
}
#[component]
fn App() -> impl IntoView {
let (count, set_count) = create_signal(0);
let double_count = move || count() * 2;
view! {
<button
on:click=move |_| {
set_count.update(|n| *n += 1);
}
>
"Click me"
</button>
<br/>
// If you have this open in CodeSandbox or an editor with
// rust-analyzer support, try hovering over `ProgressBar`,
// `max`, or `progress` to see the docs we defined above
<ProgressBar max=50 progress=count/>
// Let's use the default max value on this one
// the default is 100, so it should move half as fast
<ProgressBar progress=count/>
// Signal::derive creates a Signal wrapper from our derived signal
// using double_count means it should move twice as fast
<ProgressBar max=50 progress=Signal::derive(double_count)/>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/3-components-50t2e7?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A7%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A7%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -5,7 +5,7 @@ iterating over a list of items is a common task in web applications. Reconciling
the differences between changing sets of items can also be one of the trickiest
tasks for a framework to handle well.
Leptos supports two different patterns for iterating over items:
Leptos supports to two different patterns for iterating over items:
1. For static views: `Vec<_>`
2. For dynamic lists: `<For/>`
@@ -19,30 +19,30 @@ any `Vec<IV> where IV: IntoView` into your view. In other words, if you can rend
```rust
let values = vec![0, 1, 2];
view! {
view! { cx,
// this will just render "012"
<p>{values.clone()}</p>
// or we can wrap them in <li>
<ul>
{values.into_iter()
.map(|n| view! { <li>{n}</li>})
.map(|n| view! { cx, <li>{n}</li>})
.collect::<Vec<_>>()}
</ul>
}
```
Leptos also provides a `.collect_view()` helper function that allows you to collect any iterator of `T: IntoView` into `Vec<View>`.
Leptos also provides a `.collect_view(cx)` helper function that allows you to collect any iterator of `T: IntoView` into `Vec<View>`.
```rust
let values = vec![0, 1, 2];
view! {
view! { cx,
// this will just render "012"
<p>{values.clone()}</p>
// or we can wrap them in <li>
<ul>
{values.into_iter()
.map(|n| view! { <li>{n}</li>})
.collect_view()}
.map(|n| view! { cx, <li>{n}</li>})
.collect_view(cx)}
</ul>
}
```
@@ -51,15 +51,14 @@ The fact that the _list_ is static doesnt mean the interface needs to be stat
You can render dynamic items as part of a static list.
```rust
// create a list of 5 signals
let length = 5;
let counters = (1..=length).map(|idx| create_signal(idx));
// create a list of N signals
let counters = (1..=length).map(|idx| create_signal(cx, idx));
// each item manages a reactive view
// but the list itself will never change
let counter_buttons = counters
.map(|(count, set_count)| {
view! {
view! { cx,
<li>
<button
on:click=move |_| set_count.update(|n| *n += 1)
@@ -69,9 +68,9 @@ let counter_buttons = counters
</li>
}
})
.collect_view();
.collect_view(cx);
view! {
view! { cx,
<ul>{counter_buttons}</ul>
}
```
@@ -87,7 +86,7 @@ keyed dynamic list. It takes three props:
- `each`: a function (such as a signal) that returns the items `T` to be iterated over
- `key`: a key function that takes `&T` and returns a stable, unique key or ID
- `children`: renders each `T` into a view
- `view`: renders each `T` into a view
`key` is, well, the key. You can add, remove, and move items within the list. As
long as each items key is stable over time, the framework does not need to rerender
@@ -104,162 +103,6 @@ it is generated, and using that as an ID for the key function.
Check out the `<DynamicList/>` component below for an example.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/4-iteration-0-5-pwdn2y?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/4-iteration-sglt1o?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A6%2C%22endLineNumber%22%3A55%2C%22startColumn%22%3A5%2C%22startLineNumber%22%3A31%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/4-iteration-0-5-pwdn2y?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
// Iteration is a very common task in most applications.
// So how do you take a list of data and render it in the DOM?
// This example will show you the two ways:
// 1) for mostly-static lists, using Rust iterators
// 2) for lists that grow, shrink, or move items, using <For/>
#[component]
fn App() -> impl IntoView {
view! {
<h1>"Iteration"</h1>
<h2>"Static List"</h2>
<p>"Use this pattern if the list itself is static."</p>
<StaticList length=5/>
<h2>"Dynamic List"</h2>
<p>"Use this pattern if the rows in your list will change."</p>
<DynamicList initial_length=5/>
}
}
/// A list of counters, without the ability
/// to add or remove any.
#[component]
fn StaticList(
/// How many counters to include in this list.
length: usize,
) -> impl IntoView {
// create counter signals that start at incrementing numbers
let counters = (1..=length).map(|idx| create_signal(idx));
// when you have a list that doesn't change, you can
// manipulate it using ordinary Rust iterators
// and collect it into a Vec<_> to insert it into the DOM
let counter_buttons = counters
.map(|(count, set_count)| {
view! {
<li>
<button
on:click=move |_| set_count.update(|n| *n += 1)
>
{count}
</button>
</li>
}
})
.collect::<Vec<_>>();
// Note that if `counter_buttons` were a reactive list
// and its value changed, this would be very inefficient:
// it would rerender every row every time the list changed.
view! {
<ul>{counter_buttons}</ul>
}
}
/// A list of counters that allows you to add or
/// remove counters.
#[component]
fn DynamicList(
/// The number of counters to begin with.
initial_length: usize,
) -> impl IntoView {
// This dynamic list will use the <For/> component.
// <For/> is a keyed list. This means that each row
// has a defined key. If the key does not change, the row
// will not be re-rendered. When the list changes, only
// the minimum number of changes will be made to the DOM.
// `next_counter_id` will let us generate unique IDs
// we do this by simply incrementing the ID by one
// each time we create a counter
let mut next_counter_id = initial_length;
// we generate an initial list as in <StaticList/>
// but this time we include the ID along with the signal
let initial_counters = (0..initial_length)
.map(|id| (id, create_signal(id + 1)))
.collect::<Vec<_>>();
// now we store that initial list in a signal
// this way, we'll be able to modify the list over time,
// adding and removing counters, and it will change reactively
let (counters, set_counters) = create_signal(initial_counters);
let add_counter = move |_| {
// create a signal for the new counter
let sig = create_signal(next_counter_id + 1);
// add this counter to the list of counters
set_counters.update(move |counters| {
// since `.update()` gives us `&mut T`
// we can just use normal Vec methods like `push`
counters.push((next_counter_id, sig))
});
// increment the ID so it's always unique
next_counter_id += 1;
};
view! {
<div>
<button on:click=add_counter>
"Add Counter"
</button>
<ul>
// The <For/> component is central here
// This allows for efficient, key list rendering
<For
// `each` takes any function that returns an iterator
// this should usually be a signal or derived signal
// if it's not reactive, just render a Vec<_> instead of <For/>
each=counters
// the key should be unique and stable for each row
// using an index is usually a bad idea, unless your list
// can only grow, because moving items around inside the list
// means their indices will change and they will all rerender
key=|counter| counter.0
// `children` receives each item from your `each` iterator
// and returns a view
children=move |(id, (count, set_count))| {
view! {
<li>
<button
on:click=move |_| set_count.update(|n| *n += 1)
>
{count}
</button>
<button
on:click=move |_| {
set_counters.update(|counters| {
counters.retain(|(counter_id, _)| counter_id != &id)
});
}
>
"Remove"
</button>
</li>
}
}
/>
</ul>
</div>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/4-iteration-sglt1o?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A6%2C%22endLineNumber%22%3A55%2C%22startColumn%22%3A5%2C%22startLineNumber%22%3A31%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -1,278 +0,0 @@
# Iterating over More Complex Data with `<For/>`
This chapter goes into iteration over nested data structures in a bit
more depth. It belongs here with the other chapter on iteration, but feel
free to skip it and come back if youd like to stick with simpler subjects
for now.
## The Problem
I just said that the framework does not rerender any of the items in one of the
rows, unless the key has changed. This probably makes sense at first, but it can
easily trip you up.
Lets consider an example in which each of the items in our row is some data structure.
Imagine, for example, that the items come from some JSON array of keys and values:
```rust
#[derive(Debug, Clone)]
struct DatabaseEntry {
key: String,
value: i32,
}
```
Lets define a simple component that will iterate over the rows and display each one:
```rust
#[component]
pub fn App() -> impl IntoView {
// start with a set of three rows
let (data, set_data) = create_signal(vec![
DatabaseEntry {
key: "foo".to_string(),
value: 10,
},
DatabaseEntry {
key: "bar".to_string(),
value: 20,
},
DatabaseEntry {
key: "baz".to_string(),
value: 15,
},
]);
view! {
// when we click, update each row,
// doubling its value
<button on:click=move |_| {
set_data.update(|data| {
for row in data {
row.value *= 2;
}
});
// log the new value of the signal
logging::log!("{:?}", data.get());
}>
"Update Values"
</button>
// iterate over the rows and display each value
<For
each=data
key=|state| state.key.clone()
let:child
>
<p>{child.value}</p>
</For>
}
}
```
> Note the `let:child` syntax here. In the previous chapter we introduced `<For/>`
> with a `children` prop. We can actually create this value directly in the children
> of the `<For/>` component, without breaking out of the `view` macro: the `let:child`
> combined with `<p>{child.value}</p>` above is the equivalent of
>
> ```rust
> children=|child| view! { <p>{child.value}</p> }
> ```
When you click the `Update Values` button... nothing happens. Or rather:
the signal is updated, the new value is logged, but the `{child.value}`
for each row doesnt update.
Lets see: is that because we forgot to add a closure to make it reactive?
Lets try `{move || child.value}`.
...Nope. Still nothing.
Heres the problem: as I said, each row is only rerendered when the key changes.
Weve updated the value for each row, but not the key for any of the rows, so
nothing has rerendered. And if you look at the type of `child.value`, its a plain
`i32`, not a reactive `ReadSignal<i32>` or something. This means that even if we
wrap a closure around it, the value in this row will never update.
We have three possible solutions:
1. change the `key` so that it always updates when the data structure changes
2. change the `value` so that its reactive
3. take a reactive slice of the data structure instead of using each row directly
## Option 1: Change the Key
Each row is only rerendered when the key changes. Our rows above didnt rerender,
because the key didnt change. So: why not just force the key to change?
```rust
<For
each=data
key=|state| (state.key.clone(), state.value)
let:child
>
<p>{child.value}</p>
</For>
```
Now we include both the key and the value in the `key`. This means that whenever the
value of a row changes, `<For/>` will treat it as if its an entirely new row, and
replace the previous one.
### Pros
This is very easy. We can make it even easier by deriving `PartialEq`, `Eq`, and `Hash`
on `DatabaseEntry`, in which case we could just `key=|state| state.clone()`.
### Cons
**This is the least efficient of the three options.** Every time the value of a row
changes, it throws out the previous `<p>` element and replaces it with an entirely new
one. Rather than making a fine-grained update to the text node, in other words, it really
does rerender the entire row on every change, and this is expensive in proportion to how
complex the UI of the row is.
Youll notice we also end up cloning the whole data structure so that `<For/>` can hold
onto a copy of the key. For more complex structures, this can become a bad idea fast!
## Option 2: Nested Signals
If we do want that fine-grained reactivity for the value, one option is to wrap the `value`
of each row in a signal.
```rust
#[derive(Debug, Clone)]
struct DatabaseEntry {
key: String,
value: RwSignal<i32>,
}
```
`RwSignal<_>` is a “read-write signal,” which combines the getter and setter in one object.
Im using it here because its a little easier to store in a struct than separate getters
and setters.
```rust
#[component]
pub fn App() -> impl IntoView {
// start with a set of three rows
let (data, set_data) = create_signal(vec![
DatabaseEntry {
key: "foo".to_string(),
value: create_rw_signal(10),
},
DatabaseEntry {
key: "bar".to_string(),
value: create_rw_signal(20),
},
DatabaseEntry {
key: "baz".to_string(),
value: create_rw_signal(15),
},
]);
view! {
// when we click, update each row,
// doubling its value
<button on:click=move |_| {
data.with(|data| {
for row in data {
row.value.update(|value| *value *= 2);
}
});
// log the new value of the signal
logging::log!("{:?}", data.get());
}>
"Update Values"
</button>
// iterate over the rows and display each value
<For
each=data
key=|state| state.key.clone()
let:child
>
<p>{child.value}</p>
</For>
}
}
```
This version works! And if you look in the DOM inspector in your browser, youll
see that unlike in the previous version, in this version only the individual text
nodes are updated. Passing the signal directly into `{child.value}` works, as
signals do keep their reactivity if you pass them into the view.
Note that I changed the `set_data.update()` to a `data.with()`. `.with()` is the
non-cloning way of accessing a signals value. In this case, we are only updating
the internal values, not updating the list of values: because signals maintain their
own state, we dont actual need to update the `data` signal at all, so the immutable
`.with()` is fine here.
> In fact, this version doesnt update `data`, so the `<For/>` is essentially a static
> list as in the last chapter, and this could just be a plain iterator. But the `<For/>`
> is useful if we want to add or remove rows in the future.
### Pros
This is the most efficient option, and fits directly with the rest of the mental model
of the framework: values that change over time are wrapped in signals so the interface
can respond to them.
### Cons
Nested reactivity can be cumbersome if youre receiving data from an API or another
data source you dont control, and you dont want to create a different struct wrapping
each field in a signal.
## Option 3: Memoized Slices
Leptos provides a primitive called [`create_memo`](https://docs.rs/leptos/latest/leptos/fn.create_memo.html),
which creates a derived computation that only triggers a reactive update when its value
has changed.
This allows you to create reactive values for subfields of a larger data structure,
without needing to wrap the fields of that structure in signals.
Most of the application can remain the same as the initial (broken) version, but the `<For/>`
will be updated to this:
```rust
<For
each=move || data().into_iter().enumerate()
key=|(_, state)| state.key.clone()
children=move |(index, _)| {
let value = create_memo(move |_| {
data.with(|data| data.get(index).map(|d| d.value).unwrap_or(0))
});
view! {
<p>{value}</p>
}
}
/>
```
Youll notice a few differences here:
- we convert the `data` signal into an enumerated iterator
- we use the `children` prop explicitly, to make it easier to run some non-`view` code
- we define a `value` memo and use that in the view. This `value` field doesnt actually
use the `child` being passed into each row. Instead, it uses the index and reaches back
into the original `data` to get the value.
Every time `data` changes, now, each memo will be recalculated. If its value has changed,
it will update its text node, without rerendering the whole row.
## Pros
We get the same fine-grained reactivity of the signal-wrapped version, without needing to
wrap the data in signals.
## Cons
Its a bit more complex to set up this memo-per-row inside the `<For/>` loop rather than
using nested signals. For example, youll notice that we have to guard against the possibility
that the `data[index]` would panic by using `data.get(index)`, because this memo may be
triggered to re-run once just after the row is removed. (This is because the memo for each row
and the whole `<For/>` both depend on the same `data` signal, and the order of execution for
multiple reactive values that depend on the same signal isnt guaranteed.)
Note also that while memos memoize their reactive changes, the same
calculation does need to re-run to check the value every time, so nested reactive signals
will still be more efficient for pinpoint updates here.

View File

@@ -19,13 +19,12 @@ There are two important things to remember:
2. The `value` _attribute_ only sets the initial value of the input, i.e., it
only updates the input up to the point that you begin typing. The `value`
_property_ continues updating the input after that. You usually want to set
`prop:value` for this reason. (The same is true for `checked` and `prop:checked`
on an `<input type="checkbox">`.)
`prop:value` for this reason.
```rust
let (name, set_name) = create_signal("Controlled".to_string());
let (name, set_name) = create_signal(cx, "Controlled".to_string());
view! {
view! { cx,
<input type="text"
on:input=move |ev| {
// event_target_value is a Leptos helper function
@@ -43,33 +42,6 @@ view! {
}
```
> #### Why do you need `prop:value`?
>
> Web browsers are the most ubiquitous and stable platform for rendering graphical user interfaces in existence. They have also maintained an incredible backwards compatibility over their three decades of existence. Inevitably, this means there are some quirks.
>
> One odd quirk is that there is a distinction between HTML attributes and DOM element properties, i.e., between something called an “attribute” which is parsed from HTML and can be set on a DOM element with `.setAttribute()`, and something called a “property” which is a field of the JavaScript class representation of that parsed HTML element.
>
> In the case of an `<input value=...>`, setting the `value` _attribute_ is defined as setting the initial value for the input, and setting `value` _property_ sets its current value. It maybe easiest to understand this by opening `about:blank` and running the following JavaScript in the browser console, line by line:
>
> ```js
> // create an input and append it to the DOM
> const el = document.createElement("input");
> document.body.appendChild(el);
>
> el.setAttribute("value", "test"); // updates the input
> el.setAttribute("value", "another test"); // updates the input again
>
> // now go and type into the input: delete some characters, etc.
>
> el.setAttribute("value", "one more time?");
> // nothing should have changed. setting the "initial value" does nothing now
>
> // however...
> el.value = "But this works";
> ```
>
> Many other frontend frameworks conflate attributes and properties, or create a special case for inputs that sets the value correctly. Maybe Leptos should do this too; but for now, I prefer giving users the maximum amount of control over whether theyre setting an attribute or a property, and doing my best to educate people about the actual underlying browser behavior rather than obscuring it.
## Uncontrolled Inputs
In an "uncontrolled input," the browser controls the state of the input element.
@@ -81,9 +53,9 @@ In this example, we only notify the framework when the `<form>` fires a `submit`
event.
```rust
let (name, set_name) = create_signal("Uncontrolled".to_string());
let (name, set_name) = create_signal(cx, "Uncontrolled".to_string());
let input_element: NodeRef<Input> = create_node_ref();
let input_element: NodeRef<Input> = create_node_ref(cx);
```
`NodeRef` is a kind of reactive smart pointer: we can use it to access the
@@ -117,7 +89,7 @@ We can then call `.value()` to get the value out of the input, because `NodeRef`
gives us access to a correctly-typed HTML element.
```rust
view! {
view! { cx,
<form on:submit=on_submit>
<input type="text"
value=name
@@ -137,114 +109,6 @@ The view should be pretty self-explanatory by now. Note two things:
2. We use `node_ref` to fill the `NodeRef`. (Older examples sometimes use `_ref`.
They are the same thing, but `node_ref` has better rust-analyzer support.)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/5-forms-0-5-rf2t7c?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/5-form-inputs-ih9m62?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A12%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A12%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/5-forms-0-5-rf2t7c?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::{ev::SubmitEvent, *};
#[component]
fn App() -> impl IntoView {
view! {
<h2>"Controlled Component"</h2>
<ControlledComponent/>
<h2>"Uncontrolled Component"</h2>
<UncontrolledComponent/>
}
}
#[component]
fn ControlledComponent() -> impl IntoView {
// create a signal to hold the value
let (name, set_name) = create_signal("Controlled".to_string());
view! {
<input type="text"
// fire an event whenever the input changes
on:input=move |ev| {
// event_target_value is a Leptos helper function
// it functions the same way as event.target.value
// in JavaScript, but smooths out some of the typecasting
// necessary to make this work in Rust
set_name(event_target_value(&ev));
}
// the `prop:` syntax lets you update a DOM property,
// rather than an attribute.
//
// IMPORTANT: the `value` *attribute* only sets the
// initial value, until you have made a change.
// The `value` *property* sets the current value.
// This is a quirk of the DOM; I didn't invent it.
// Other frameworks gloss this over; I think it's
// more important to give you access to the browser
// as it really works.
//
// tl;dr: use prop:value for form inputs
prop:value=name
/>
<p>"Name is: " {name}</p>
}
}
#[component]
fn UncontrolledComponent() -> impl IntoView {
// import the type for <input>
use leptos::html::Input;
let (name, set_name) = create_signal("Uncontrolled".to_string());
// we'll use a NodeRef to store a reference to the input element
// this will be filled when the element is created
let input_element: NodeRef<Input> = create_node_ref();
// fires when the form `submit` event happens
// this will store the value of the <input> in our signal
let on_submit = move |ev: SubmitEvent| {
// stop the page from reloading!
ev.prevent_default();
// here, we'll extract the value from the input
let value = input_element()
// event handlers can only fire after the view
// is mounted to the DOM, so the `NodeRef` will be `Some`
.expect("<input> to exist")
// `NodeRef` implements `Deref` for the DOM element type
// this means we can call`HtmlInputElement::value()`
// to get the current value of the input
.value();
set_name(value);
};
view! {
<form on:submit=on_submit>
<input type="text"
// here, we use the `value` *attribute* to set only
// the initial value, letting the browser maintain
// the state after that
value=name
// store a reference to this input in `input_element`
node_ref=input_element
/>
<input type="submit" value="Submit"/>
</form>
<p>"Name is: " {name}</p>
}
}
// This `main` function is the entry point into the app
// It just mounts our component to the <body>
// Because we defined it as `fn App`, we can now use it in a
// template as <App/>
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/5-form-inputs-ih9m62?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A12%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A12%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -38,7 +38,7 @@ special knowledge.
For example, lets start with a simple signal and derived signal:
```rust
let (value, set_value) = create_signal(0);
let (value, set_value) = create_signal(cx, 0);
let is_odd = move || value() & 1 == 1;
```
@@ -54,7 +54,7 @@ Lets say I want to render some text if the number is odd, and some other text
if its even. Well, how about this?
```rust
view! {
view! { cx,
<p>
{move || if is_odd() {
"Odd"
@@ -81,7 +81,7 @@ let message = move || {
}
};
view! {
view! { cx,
<p>{message}</p>
}
```
@@ -90,7 +90,7 @@ This works fine. We can make it a little shorter if wed like, using `bool::th
```rust
let message = move || is_odd().then(|| "Ding ding ding!");
view! {
view! { cx,
<p>{message}</p>
}
```
@@ -112,7 +112,7 @@ let message = move || {
_ => "Even"
}
};
view! {
view! { cx,
<p>{message}</p>
}
```
@@ -131,7 +131,7 @@ above, where the value switches from even to odd on every change, this is fine.
But consider the following example:
```rust
let (value, set_value) = create_signal(0);
let (value, set_value) = create_signal(cx, 0);
let message = move || if value() > 5 {
"Big"
@@ -139,7 +139,7 @@ let message = move || if value() > 5 {
"Small"
};
view! {
view! { cx,
<p>{message}</p>
}
```
@@ -148,10 +148,10 @@ This _works_, for sure. But if you added a log, you might be surprised
```rust
let message = move || if value() > 5 {
logging::log!("{}: rendering Big", value());
log!("{}: rendering Big", value());
"Big"
} else {
logging::log!("{}: rendering Small", value());
log!("{}: rendering Small", value());
"Small"
};
```
@@ -194,12 +194,12 @@ the answer. You pass it a `when` condition function, a `fallback` to be shown if
the `when` function returns `false`, and children to be rendered if `when` is `true`.
```rust
let (value, set_value) = create_signal(0);
let (value, set_value) = create_signal(cx, 0);
view! {
view! { cx,
<Show
when=move || { value() > 5 }
fallback=|| view! { <Small/> }
when=move || value() > 5
fallback=|cx| view! { cx, <Small/> }
>
<Big/>
</Show>
@@ -208,8 +208,7 @@ view! {
`<Show/>` memoizes the `when` condition, so it only renders its `<Small/>` once,
continuing to show the same component until `value` is greater than five;
then it renders `<Big/>` once, continuing to show it indefinitely or until `value`
goes below five and then renders `<Small/>` again.
then it renders `<Big/>` once, continuing to show it indefinitely.
This is a helpful tool to avoid rerendering when using dynamic `if` expressions.
As always, there's some overhead: for a very simple node (like updating a single
@@ -228,19 +227,19 @@ can be a little annoying if youre returning different HTML elements from
different branches of a conditional:
```rust,compile_error
view! {
view! { cx,
<main>
{move || match is_odd() {
true if value() == 1 => {
// returns HtmlElement<Pre>
view! { <pre>"One"</pre> }
view! { cx, <pre>"One"</pre> }
},
false if value() == 2 => {
// returns HtmlElement<P>
view! { <p>"Two"</p> }
view! { cx, <p>"Two"</p> }
}
// returns HtmlElement<Textarea>
_ => view! { <textarea>{value()}</textarea> }
_ => view! { cx, <textarea>{value()}</textarea> }
}}
</main>
}
@@ -260,125 +259,29 @@ to get yourself out of this situation:
1. If you have multiple `HtmlElement` types, convert them to `HtmlElement<AnyElement>`
with [`.into_any()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.into_any)
2. If you have a variety of view types that are not all `HtmlElement`, convert them to
`View`s with [`.into_view()`](https://docs.rs/leptos/latest/leptos/trait.IntoView.html#tymethod.into_view).
`View`s with [`.into_view(cx)`](https://docs.rs/leptos/latest/leptos/trait.IntoView.html#tymethod.into_view).
Heres the same example, with the conversion added:
```rust,compile_error
view! {
view! { cx,
<main>
{move || match is_odd() {
true if value() == 1 => {
// returns HtmlElement<Pre>
view! { <pre>"One"</pre> }.into_any()
view! { cx, <pre>"One"</pre> }.into_any()
},
false if value() == 2 => {
// returns HtmlElement<P>
view! { <p>"Two"</p> }.into_any()
view! { cx, <p>"Two"</p> }.into_any()
}
// returns HtmlElement<Textarea>
_ => view! { <textarea>{value()}</textarea> }.into_any()
_ => view! { cx, <textarea>{value()}</textarea> }.into_any()
}}
</main>
}
```
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/6-control-flow-0-5-4yn7qz?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/6-control-flow-in-view-zttwfx?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/6-control-flow-0-5-4yn7qz?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
#[component]
fn App() -> impl IntoView {
let (value, set_value) = create_signal(0);
let is_odd = move || value() & 1 == 1;
let odd_text = move || if is_odd() { Some("How odd!") } else { None };
view! {
<h1>"Control Flow"</h1>
// Simple UI to update and show a value
<button on:click=move |_| set_value.update(|n| *n += 1)>
"+1"
</button>
<p>"Value is: " {value}</p>
<hr/>
<h2><code>"Option<T>"</code></h2>
// For any `T` that implements `IntoView`,
// so does `Option<T>`
<p>{odd_text}</p>
// This means you can use `Option` methods on it
<p>{move || odd_text().map(|text| text.len())}</p>
<h2>"Conditional Logic"</h2>
// You can do dynamic conditional if-then-else
// logic in several ways
//
// a. An "if" expression in a function
// This will simply re-render every time the value
// changes, which makes it good for lightweight UI
<p>
{move || if is_odd() {
"Odd"
} else {
"Even"
}}
</p>
// b. Toggling some kind of class
// This is smart for an element that's going to
// toggled often, because it doesn't destroy
// it in between states
// (you can find the `hidden` class in `index.html`)
<p class:hidden=is_odd>"Appears if even."</p>
// c. The <Show/> component
// This only renders the fallback and the child
// once, lazily, and toggles between them when
// needed. This makes it more efficient in many cases
// than a {move || if ...} block
<Show when=is_odd
fallback=|| view! { <p>"Even steven"</p> }
>
<p>"Oddment"</p>
</Show>
// d. Because `bool::then()` converts a `bool` to
// `Option`, you can use it to create a show/hide toggled
{move || is_odd().then(|| view! { <p>"Oddity!"</p> })}
<h2>"Converting between Types"</h2>
// e. Note: if branches return different types,
// you can convert between them with
// `.into_any()` (for different HTML element types)
// or `.into_view()` (for all view types)
{move || match is_odd() {
true if value() == 1 => {
// <pre> returns HtmlElement<Pre>
view! { <pre>"One"</pre> }.into_any()
},
false if value() == 2 => {
// <p> returns HtmlElement<P>
// so we convert into a more generic type
view! { <p>"Two"</p> }.into_any()
}
_ => view! { <textarea>{value()}</textarea> }.into_any()
}}
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/6-control-flow-in-view-zttwfx?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -10,13 +10,13 @@ Lets start with a simple component to capture a number input.
```rust
#[component]
fn NumericInput() -> impl IntoView {
let (value, set_value) = create_signal(Ok(0));
fn NumericInput(cx: Scope) -> impl IntoView {
let (value, set_value) = create_signal(cx, Ok(0));
// when input changes, try to parse a number from the input
let on_input = move |ev| set_value(event_target_value(&ev).parse::<i32>());
view! {
view! { cx,
<label>
"Type a number (or not!)"
<input type="number" on:input=on_input/>
@@ -60,27 +60,27 @@ Lets add an `<ErrorBoundary/>` to this example.
```rust
#[component]
fn NumericInput() -> impl IntoView {
let (value, set_value) = create_signal(Ok(0));
fn NumericInput(cx: Scope) -> impl IntoView {
let (value, set_value) = create_signal(cx, Ok(0));
let on_input = move |ev| set_value(event_target_value(&ev).parse::<i32>());
view! {
view! { cx,
<h1>"Error Handling"</h1>
<label>
"Type a number (or something that's not a number!)"
<input type="number" on:input=on_input/>
<ErrorBoundary
// the fallback receives a signal containing current errors
fallback=|errors| view! {
fallback=|cx, errors| view! { cx,
<div class="error">
<p>"Not a number! Errors: "</p>
// we can render a list of errors as strings, if we'd like
<ul>
{move || errors.get()
.into_iter()
.map(|(_, e)| view! { <li>{e.to_string()}</li>})
.collect_view()
.map(|(_, e)| view! { cx, <li>{e.to_string()}</li>})
.collect_view(cx)
}
</ul>
</div>
@@ -110,66 +110,6 @@ Not a number! Errors:
If you fix the error, the error message will disappear and the content youre wrapping in
an `<ErrorBoundary/>` will appear again.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/7-errors-0-5-5mptv9?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/7-error-handling-and-error-boundaries-sroncx?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/7-errors-0-5-5mptv9?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
#[component]
fn App() -> impl IntoView {
let (value, set_value) = create_signal(Ok(0));
// when input changes, try to parse a number from the input
let on_input = move |ev| set_value(event_target_value(&ev).parse::<i32>());
view! {
<h1>"Error Handling"</h1>
<label>
"Type a number (or something that's not a number!)"
<input type="number" on:input=on_input/>
// If an `Err(_) had been rendered inside the <ErrorBoundary/>,
// the fallback will be displayed. Otherwise, the children of the
// <ErrorBoundary/> will be displayed.
<ErrorBoundary
// the fallback receives a signal containing current errors
fallback=|errors| view! {
<div class="error">
<p>"Not a number! Errors: "</p>
// we can render a list of errors
// as strings, if we'd like
<ul>
{move || errors.get()
.into_iter()
.map(|(_, e)| view! { <li>{e.to_string()}</li>})
.collect::<Vec<_>>()
}
</ul>
</div>
}
>
<p>
"You entered "
// because `value` is `Result<i32, _>`,
// it will render the `i32` if it is `Ok`,
// and render nothing and trigger the error boundary
// if it is `Err`. It's a signal, so this will dynamically
// update when `value` changes
<strong>{value}</strong>
</p>
</ErrorBoundary>
</label>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/7-error-handling-and-error-boundaries-sroncx?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A2%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A2%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -29,17 +29,17 @@ it in the child. This lets you manipulate the state of the parent from the child
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
view! { cx,
<p>"Toggled? " {toggled}</p>
<ButtonA setter=set_toggled/>
}
}
#[component]
pub fn ButtonA(setter: WriteSignal<bool>) -> impl IntoView {
view! {
pub fn ButtonA(cx: Scope, setter: WriteSignal<bool>) -> impl IntoView {
view! { cx,
<button
on:click=move |_| setter.update(|value| *value = !*value)
>
@@ -62,9 +62,9 @@ Another approach would be to pass a callback to the child: say, `on_click`.
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
view! { cx,
<p>"Toggled? " {toggled}</p>
<ButtonB on_click=move |_| set_toggled.update(|value| *value = !*value)/>
}
@@ -72,9 +72,14 @@ pub fn App() -> impl IntoView {
#[component]
pub fn ButtonB(#[prop(into)] on_click: Callback<MouseEvent>) -> impl IntoView
pub fn ButtonB<F>(
cx: Scope,
on_click: F,
) -> impl IntoView
where
F: Fn(MouseEvent) + 'static,
{
view! {
view! { cx,
<button on:click=on_click>
"Toggle"
</button>
@@ -88,50 +93,10 @@ of keeping local state local, preventing the problem of spaghetti mutation. But
the logic to mutate that signal needs to exist up in `<App/>`, not down in `<ButtonB/>`. These
are real trade-offs, not a simple right-or-wrong choice.
> Note the way we use the `Callback<In, Out>` type. This is basically a
> wrapper around a closure `Fn(In) -> Out` that is also `Copy` and makes it
> easy to pass around.
>
> We also used the `#[prop(into)]` attribute so we can pass a normal closure into
> `on_click`. Please see the [chapter "`into` Props"](./03_components.md#into-props) for more details.
### 2.1 Use Closure instead of `Callback`
You can use a Rust closure `Fn(MouseEvent)` directly instead of `Callback`:
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
<p>"Toggled? " {toggled}</p>
<ButtonB on_click=move |_| set_toggled.update(|value| *value = !*value)/>
}
}
#[component]
pub fn ButtonB<F>(on_click: F) -> impl IntoView
where
F: Fn(MouseEvent) + 'static,
pub fn ButtonB(#[prop(into)] on_click: Callback<MouseEvent>) -> impl IntoView
{
view! {
<button on:click=on_click>
"Toggle"
</button>
}
}
```
The code is very similar in this case. On more advanced use-cases using a
closure might require some cloning compared to using a `Callback`.
> Note the way we declare the generic type `F` here for the callback. If youre
> confused, look back at the [generic props](./03_components.html#generic-props) section
> of the chapter on components.
## 3. Use an Event Listener
You can actually write Option 2 in a slightly different way. If the callback maps directly onto
@@ -140,9 +105,9 @@ in your `view` macro in `<App/>`.
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
view! { cx,
<p>"Toggled? " {toggled}</p>
// note the on:click instead of on_click
// this is the same syntax as an HTML element event listener
@@ -152,8 +117,8 @@ pub fn App() -> impl IntoView {
#[component]
pub fn ButtonC<F>() -> impl IntoView {
view! {
pub fn ButtonC<F>(cx: Scope) -> impl IntoView {
view! { cx,
<button>"Toggle"</button>
}
}
@@ -176,17 +141,17 @@ tree:
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
view! { cx,
<p>"Toggled? " {toggled}</p>
<Layout/>
}
}
#[component]
pub fn Layout() -> impl IntoView {
view! {
pub fn Layout(cx: Scope) -> impl IntoView {
view! { cx,
<header>
<h1>"My Page"</h1>
</header>
@@ -197,8 +162,8 @@ pub fn Layout() -> impl IntoView {
}
#[component]
pub fn Content() -> impl IntoView {
view! {
pub fn Content(cx: Scope) -> impl IntoView {
view! { cx,
<div class="content">
<ButtonD/>
</div>
@@ -206,7 +171,7 @@ pub fn Content() -> impl IntoView {
}
#[component]
pub fn ButtonD<F>() -> impl IntoView {
pub fn ButtonD<F>(cx: Scope) -> impl IntoView {
todo!()
}
```
@@ -217,17 +182,17 @@ pass your `WriteSignal` to its props. You could do whats sometimes called
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
view! {
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
view! { cx,
<p>"Toggled? " {toggled}</p>
<Layout set_toggled/>
}
}
#[component]
pub fn Layout(set_toggled: WriteSignal<bool>) -> impl IntoView {
view! {
pub fn Layout(cx: Scope, set_toggled: WriteSignal<bool>) -> impl IntoView {
view! { cx,
<header>
<h1>"My Page"</h1>
</header>
@@ -238,8 +203,8 @@ pub fn Layout(set_toggled: WriteSignal<bool>) -> impl IntoView {
}
#[component]
pub fn Content(set_toggled: WriteSignal<bool>) -> impl IntoView {
view! {
pub fn Content(cx: Scope, set_toggled: WriteSignal<bool>) -> impl IntoView {
view! { cx,
<div class="content">
<ButtonD set_toggled/>
</div>
@@ -247,7 +212,7 @@ pub fn Content(set_toggled: WriteSignal<bool>) -> impl IntoView {
}
#[component]
pub fn ButtonD<F>(set_toggled: WriteSignal<bool>) -> impl IntoView {
pub fn ButtonD<F>(cx: Scope, set_toggled: WriteSignal<bool>) -> impl IntoView {
todo!()
}
```
@@ -272,13 +237,13 @@ unnecessary prop drilling.
```rust
#[component]
pub fn App() -> impl IntoView {
let (toggled, set_toggled) = create_signal(false);
pub fn App(cx: Scope) -> impl IntoView {
let (toggled, set_toggled) = create_signal(cx, false);
// share `set_toggled` with all children of this component
provide_context(set_toggled);
provide_context(cx, set_toggled);
view! {
view! { cx,
<p>"Toggled? " {toggled}</p>
<Layout/>
}
@@ -287,14 +252,14 @@ pub fn App() -> impl IntoView {
// <Layout/> and <Content/> omitted
#[component]
pub fn ButtonD() -> impl IntoView {
pub fn ButtonD(cx: Scope) -> impl IntoView {
// use_context searches up the context tree, hoping to
// find a `WriteSignal<bool>`
// in this case, I .expect() because I know I provided it
let setter = use_context::<WriteSignal<bool>>()
let setter = use_context::<WriteSignal<bool>>(cx)
.expect("to have found the setter provided");
view! {
view! { cx,
<button
on:click=move |_| setter.update(|value| *value = !*value)
>
@@ -320,145 +285,6 @@ in `<ButtonD/>` and a single text node in `<App/>`. Its as if the components
themselves dont exist at all. And, well... at runtime, they dont. Its just
signals and effects, all the way down.
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/8-parent-child-0-5-7rz7qd?file=%2Fsrc%2Fmain.rs%3A1%2C2)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/8-parent-child-communication-84we8m?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/8-parent-child-0-5-7rz7qd?file=%2Fsrc%2Fmain.rs%3A1%2C2" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::{ev::MouseEvent, *};
// This highlights four different ways that child components can communicate
// with their parent:
// 1) <ButtonA/>: passing a WriteSignal as one of the child component props,
// for the child component to write into and the parent to read
// 2) <ButtonB/>: passing a closure as one of the child component props, for
// the child component to call
// 3) <ButtonC/>: adding an `on:` event listener to a component
// 4) <ButtonD/>: providing a context that is used in the component (rather than prop drilling)
#[derive(Copy, Clone)]
struct SmallcapsContext(WriteSignal<bool>);
#[component]
pub fn App() -> impl IntoView {
// just some signals to toggle three classes on our <p>
let (red, set_red) = create_signal(false);
let (right, set_right) = create_signal(false);
let (italics, set_italics) = create_signal(false);
let (smallcaps, set_smallcaps) = create_signal(false);
// the newtype pattern isn't *necessary* here but is a good practice
// it avoids confusion with other possible future `WriteSignal<bool>` contexts
// and makes it easier to refer to it in ButtonC
provide_context(SmallcapsContext(set_smallcaps));
view! {
<main>
<p
// class: attributes take F: Fn() => bool, and these signals all implement Fn()
class:red=red
class:right=right
class:italics=italics
class:smallcaps=smallcaps
>
"Lorem ipsum sit dolor amet."
</p>
// Button A: pass the signal setter
<ButtonA setter=set_red/>
// Button B: pass a closure
<ButtonB on_click=move |_| set_right.update(|value| *value = !*value)/>
// Button B: use a regular event listener
// setting an event listener on a component like this applies it
// to each of the top-level elements the component returns
<ButtonC on:click=move |_| set_italics.update(|value| *value = !*value)/>
// Button D gets its setter from context rather than props
<ButtonD/>
</main>
}
}
/// Button A receives a signal setter and updates the signal itself
#[component]
pub fn ButtonA(
/// Signal that will be toggled when the button is clicked.
setter: WriteSignal<bool>,
) -> impl IntoView {
view! {
<button
on:click=move |_| setter.update(|value| *value = !*value)
>
"Toggle Red"
</button>
}
}
/// Button B receives a closure
#[component]
pub fn ButtonB<F>(
/// Callback that will be invoked when the button is clicked.
on_click: F,
) -> impl IntoView
where
F: Fn(MouseEvent) + 'static,
{
view! {
<button
on:click=on_click
>
"Toggle Right"
</button>
}
// just a note: in an ordinary function ButtonB could take on_click: impl Fn(MouseEvent) + 'static
// and save you from typing out the generic
// the component macro actually expands to define a
//
// struct ButtonBProps<F> where F: Fn(MouseEvent) + 'static {
// on_click: F
// }
//
// this is what allows us to have named props in our component invocation,
// instead of an ordered list of function arguments
// if Rust ever had named function arguments we could drop this requirement
}
/// Button C is a dummy: it renders a button but doesn't handle
/// its click. Instead, the parent component adds an event listener.
#[component]
pub fn ButtonC() -> impl IntoView {
view! {
<button>
"Toggle Italics"
</button>
}
}
/// Button D is very similar to Button A, but instead of passing the setter as a prop
/// we get it from the context
#[component]
pub fn ButtonD() -> impl IntoView {
let setter = use_context::<SmallcapsContext>().unwrap().0;
view! {
<button
on:click=move |_| setter.update(|value| *value = !*value)
>
"Toggle Small Caps"
</button>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/8-parent-child-communication-84we8m?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A1%2C%22endLineNumber%22%3A3%2C%22startColumn%22%3A1%2C%22startLineNumber%22%3A3%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -5,7 +5,7 @@ children into an HTML element. For example, imagine I have a `<FancyForm/>` comp
that enhances an HTML `<form>`. I need some way to pass all its inputs.
```rust
view! {
view! { cx,
<Form>
<fieldset>
<label>
@@ -28,12 +28,12 @@ other components:
In fact, youve already seen these both in action in the [`<Show/>`](/view/06_control_flow.html#show) component:
```rust
view! {
view! { cx,
<Show
// `when` is a normal prop
when=move || value() > 5
// `fallback` is a "render prop": a function that returns a view
fallback=|| view! { <Small/> }
fallback=|cx| view! { cx, <Small/> }
>
// `<Big/>` (and anything else here)
// will be given to the `children` prop
@@ -47,6 +47,7 @@ Lets define a component that takes some children and a render prop.
```rust
#[component]
pub fn TakesChildren<F, IV>(
cx: Scope,
/// Takes a function (type F) that returns anything that can be
/// converted into a View (type IV)
render_prop: F,
@@ -57,19 +58,19 @@ where
F: Fn() -> IV,
IV: IntoView,
{
view! {
view! { cx,
<h2>"Render Prop"</h2>
{render_prop()}
<h2>"Children"</h2>
{children()}
{children(cx)}
}
}
```
`render_prop` and `children` are both functions, so we can call them to generate
the appropriate views. `children`, in particular, is an alias for
`Box<dyn FnOnce() -> Fragment>`. (Aren't you glad we named it `Children` instead?)
`Box<dyn FnOnce(Scope) -> Fragment>`. (Aren't you glad we named it `Children` instead?)
> If you need a `Fn` or `FnMut` here because you need to call `children` more than once,
> we also provide `ChildrenFn` and `ChildrenMut` aliases.
@@ -77,8 +78,8 @@ the appropriate views. `children`, in particular, is an alias for
We can use the component like this:
```rust
view! {
<TakesChildren render_prop=|| view! { <p>"Hi, there!"</p> }>
view! { cx,
<TakesChildren render_prop=|| view! { cx, <p>"Hi, there!"</p> }>
// these get passed to `children`
"Some text"
<span>"A span"</span>
@@ -96,15 +97,15 @@ a component that takes its children and turns them into an unordered list.
```rust
#[component]
pub fn WrapsChildren(children: Children) -> impl IntoView {
pub fn WrapsChildren(cx: Scope, children: Children) -> impl IntoView {
// Fragment has `nodes` field that contains a Vec<View>
let children = children()
let children = children(cx)
.nodes
.into_iter()
.map(|child| view! { <li>{child}</li> })
.collect_view();
.map(|child| view! { cx, <li>{child}</li> })
.collect_view(cx);
view! {
view! { cx,
<ul>{children}</ul>
}
}
@@ -113,117 +114,15 @@ pub fn WrapsChildren(children: Children) -> impl IntoView {
Calling it like this will create a list:
```rust
view! {
<WrapsChildren>
view! { cx,
<WrappedChildren>
"A"
"B"
"C"
</WrapsChildren>
</WrappedChildren>
}
```
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/9-component-children-0-5-m4jwhp?file=%2Fsrc%2Fmain.rs%3A1%2C1)
[Click to open CodeSandbox.](https://codesandbox.io/p/sandbox/9-component-children-2wrdfd?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A12%2C%22endLineNumber%22%3A19%2C%22startColumn%22%3A12%2C%22startLineNumber%22%3A19%7D%5D)
<iframe src="https://codesandbox.io/p/sandbox/9-component-children-0-5-m4jwhp?file=%2Fsrc%2Fmain.rs%3A1%2C1" width="100%" height="1000px" style="max-height: 100vh"></iframe>
<details>
<summary>CodeSandbox Source</summary>
```rust
use leptos::*;
// Often, you want to pass some kind of child view to another
// component. There are two basic patterns for doing this:
// - "render props": creating a component prop that takes a function
// that creates a view
// - the `children` prop: a special property that contains content
// passed as the children of a component in your view, not as a
// property
#[component]
pub fn App() -> impl IntoView {
let (items, set_items) = create_signal(vec![0, 1, 2]);
let render_prop = move || {
// items.with(...) reacts to the value without cloning
// by applying a function. Here, we pass the `len` method
// on a `Vec<_>` directly
let len = move || items.with(Vec::len);
view! {
<p>"Length: " {len}</p>
}
};
view! {
// This component just displays the two kinds of children,
// embedding them in some other markup
<TakesChildren
// for component props, you can shorthand
// `render_prop=render_prop` => `render_prop`
// (this doesn't work for HTML element attributes)
render_prop
>
// these look just like the children of an HTML element
<p>"Here's a child."</p>
<p>"Here's another child."</p>
</TakesChildren>
<hr/>
// This component actually iterates over and wraps the children
<WrapsChildren>
<p>"Here's a child."</p>
<p>"Here's another child."</p>
</WrapsChildren>
}
}
/// Displays a `render_prop` and some children within markup.
#[component]
pub fn TakesChildren<F, IV>(
/// Takes a function (type F) that returns anything that can be
/// converted into a View (type IV)
render_prop: F,
/// `children` takes the `Children` type
/// this is an alias for `Box<dyn FnOnce() -> Fragment>`
/// ... aren't you glad we named it `Children` instead?
children: Children,
) -> impl IntoView
where
F: Fn() -> IV,
IV: IntoView,
{
view! {
<h1><code>"<TakesChildren/>"</code></h1>
<h2>"Render Prop"</h2>
{render_prop()}
<hr/>
<h2>"Children"</h2>
{children()}
}
}
/// Wraps each child in an `<li>` and embeds them in a `<ul>`.
#[component]
pub fn WrapsChildren(children: Children) -> impl IntoView {
// children() returns a `Fragment`, which has a
// `nodes` field that contains a Vec<View>
// this means we can iterate over the children
// to create something new!
let children = children()
.nodes
.into_iter()
.map(|child| view! { <li>{child}</li> })
.collect::<Vec<_>>();
view! {
<h1><code>"<WrapsChildren/>"</code></h1>
// wrap our wrapped children in a UL
<ul>{children}</ul>
}
}
fn main() {
leptos::mount_to_body(App)
}
```
</details>
</preview>
<iframe src="https://codesandbox.io/p/sandbox/9-component-children-2wrdfd?file=%2Fsrc%2Fmain.rs&selection=%5B%7B%22endColumn%22%3A12%2C%22endLineNumber%22%3A19%2C%22startColumn%22%3A12%2C%22startLineNumber%22%3A19%7D%5D" width="100%" height="1000px" style="max-height: 100vh"></iframe>

View File

@@ -1,98 +0,0 @@
# No Macros: The View Builder Syntax
> If youre perfectly happy with the `view!` macro syntax described so far, youre welcome to skip this chapter. The builder syntax described in this section is always available, but never required.
For one reason or another, many developers would prefer to avoid macros. Perhaps you dont like the limited `rustfmt` support. (Although, you should check out [`leptosfmt`](https://github.com/bram209/leptosfmt), which is an excellent tool!) Perhaps you worry about the effect of macros on compile time. Perhaps you prefer the aesthetics of pure Rust syntax, or you have trouble context-switching between an HTML-like syntax and your Rust code. Or perhaps you want more flexibility in how you create and manipulate HTML elements than the `view` macro provides.
If you fall into any of those camps, the builder syntax may be for you.
The `view` macro expands an HTML-like syntax to a series of Rust functions and method calls. If youd rather not use the `view` macro, you can simply use that expanded syntax yourself. And its actually pretty nice!
First off, if you want you can even drop the `#[component]` macro: a component is just a setup function that creates your view, so you can define a component as a simple function call:
```rust
pub fn counter(initial_value: i32, step: u32) -> impl IntoView { }
```
Elements are created by calling a function with the same name as the HTML element:
```rust
p()
```
You can add children to the element with [`.child()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.child), which takes a single child or a tuple or array of types that implement [`IntoView`](https://docs.rs/leptos/latest/leptos/trait.IntoView.html).
```rust
p().child((em().child("Big, "), strong().child("bold "), "text"))
```
Attributes are added with [`.attr()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.attr). This can take any of the same types that you could pass as an attribute into the view macro (types that implement [`IntoAttribute`](https://docs.rs/leptos/latest/leptos/trait.IntoAttribute.html)).
```rust
p().attr("id", "foo").attr("data-count", move || count().to_string())
```
Similarly, the `class:`, `prop:`, and `style:` syntaxes map directly onto [`.class()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.class), [`.prop()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.prop), and [`.style()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.style) methods.
Event listeners can be added with [`.on()`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.on). Typed events found in [`leptos::ev`](https://docs.rs/leptos/latest/leptos/ev/index.html) prevent typos in event names and allow for correct type inference in the callback function.
```rust
button()
.on(ev::click, move |_| set_count.update(|count| count.clear()))
.child("Clear")
```
> Many additional methods can be found in the [`HtmlElement`](https://docs.rs/leptos/latest/leptos/struct.HtmlElement.html#method.child) docs, including some methods that are not directly available in the `view` macro.
All of this adds up to a very Rusty syntax to build full-featured views, if you prefer this style.
```rust
/// A simple counter view.
// A component is really just a function call: it runs once to create the DOM and reactive system
pub fn counter(initial_value: i32, step: u32) -> impl IntoView {
let (count, set_count) = create_signal(0);
div()
.child((
button()
// typed events found in leptos::ev
// 1) prevent typos in event names
// 2) allow for correct type inference in callbacks
.on(ev::click, move |_| set_count.update(|count| count.clear()))
.child("Clear"),
button()
.on(ev::click, move |_| {
set_count.update(|count| count.decrease())
})
.child("-1"),
span().child(("Value: ", move || count.get().value(), "!")),
button()
.on(ev::click, move |_| {
set_count.update(|count| count.increase())
})
.child("+1"),
))
}
```
This also has the benefit of being more flexible: because these are all plain Rust functions and methods, its easier to use them in things like iterator adapters without any additional “magic”:
```rust
// take some set of attribute names and values
let attrs: Vec<(&str, AttributeValue)> = todo!();
// you can use the builder syntax to “spread” these onto the
// element in a way thats not possible with the view macro
let p = attrs
.into_iter()
.fold(p(), |el, (name, value)| el.attr(name, value));
```
> ## Performance Note
>
> One caveat: the `view` macro applies significant optimizations in server-side-rendering (SSR) mode to improve HTML rendering performance significantly (think 2-4x faster, depending on the characteristics of any given app). It does this by analyzing your `view` at compile time and converting the static parts into simple HTML strings, rather than expanding them into the builder syntax.
>
> This means two things:
>
> 1. The builder syntax and `view` macro should not be mixed, or should only be mixed very carefully: at least in SSR mode, the output of the `view` should be treated as a “black box” that cant have additional builder methods applied to it without causing inconsistencies.
> 2. Using the builder syntax will result in less-than-optimal SSR performance. It wont be slow, by any means (and its worth running your own benchmarks in any case), just slower than the `view`-optimized version.

View File

@@ -1,153 +1,57 @@
extend = [{ path = "./cargo-make/main.toml" }]
extend = [{ path = "./cargo-make/common.toml" }]
[env]
CARGO_MAKE_EXTEND_WORKSPACE_MAKEFILE = true
CARGO_MAKE_CARGO_BUILD_TEST_FLAGS = ""
CARGO_MAKE_WORKSPACE_EMULATION = true
CARGO_MAKE_CRATE_WORKSPACE_MEMBERS = [
"animated_show",
"counter",
"counter_isomorphic",
"counters",
"counters_stable",
"counter_url_query",
"counter_without_macros",
"error_boundary",
"errors_axum",
"fetch",
"hackernews",
"hackernews_axum",
"js-framework-benchmark",
"login_with_token_csr_only",
"parent_child",
"router",
"session_auth_axum",
"slots",
"ssr_modes",
"ssr_modes_axum",
"suspense_tests",
"tailwind_actix",
"tailwind_csr",
"tailwind_axum",
"timer",
"todo_app_sqlite",
"todo_app_sqlite_axum",
"todo_app_sqlite_viz",
"todomvc",
"counter",
"counter_isomorphic",
"counters",
"counters_stable",
"counter_without_macros",
"error_boundary",
"errors_axum",
"fetch",
"hackernews",
"hackernews_axum",
"login_with_token_csr_only",
"parent_child",
"router",
"session_auth_axum",
"ssr_modes",
"ssr_modes_axum",
"tailwind",
"tailwind_csr_trunk",
"todo_app_sqlite",
"todo_app_sqlite_axum",
"todo_app_sqlite_viz",
"todomvc",
]
[tasks.gen-members]
workspace = false
description = "Generate the list of workspace members"
script = '''
examples=$(ls |
grep -v .md |
grep -v Makefile.toml |
grep -v cargo-make |
grep -v gtk |
jq -R -s -c 'split("\n")[:-1]')
echo "CARGO_MAKE_CRATE_WORKSPACE_MEMBERS = $examples"
'''
[tasks.verify-flow]
description = "Provides pre and post hooks for verify"
dependencies = ["pre-verify", "verify", "post-verify"]
[tasks.test-report]
workspace = false
description = "report web testing technology used by examples - OPTION: [all]"
script = '''
set -emu
[tasks.verify]
description = "Run all quality checks and tests"
dependencies = ["check-style", "test-unit-and-web"]
BOLD="\e[1m"
GREEN="\e[0;32m"
ITALIC="\e[3m"
YELLOW="\e[0;33m"
RESET="\e[0m"
[tasks.test-unit-and-web]
description = "Run all unit and web tests"
dependencies = ["test-flow", "web-test-flow"]
echo
echo "${YELLOW}Web Test Technology${RESET}"
echo
[tasks.pre-verify]
makefile_paths=$(find . -name Makefile.toml -not -path '*/target/*' -not -path '*/node_modules/*' |
sed 's%./%%' |
sed 's%/Makefile.toml%%' |
grep -v Makefile.toml |
sort -u)
[tasks.post-verify]
dependencies = ["clean-all"]
start_path=$(pwd)
[tasks.web-test-flow]
description = "Provides pre and post hooks for web-test"
dependencies = ["pre-web-test", "web-test", "post-web-test"]
for path in $makefile_paths; do
cd $path
[tasks.pre-web-test]
crate_symbols=
[tasks.web-test]
pw_count=$(find . -name playwright.config.ts | wc -l)
while read -r line; do
case $line in
*"cucumber"*)
crate_symbols=$crate_symbols"C"
;;
*"fantoccini"*)
crate_symbols=$crate_symbols"D"
;;
esac
done <"./Cargo.toml"
while read -r line; do
case $line in
*"cargo-make/wasm-test.toml"*)
crate_symbols=$crate_symbols"W"
;;
*"cargo-make/playwright-test.toml"*)
crate_symbols=$crate_symbols"P"
crate_symbols=$crate_symbols"N"
;;
*"cargo-make/playwright-trunk-test.toml"*)
crate_symbols=$crate_symbols"P"
crate_symbols=$crate_symbols"T"
;;
*"cargo-make/trunk_server.toml"*)
crate_symbols=$crate_symbols"T"
;;
*"cargo-make/cargo-leptos-webdriver-test.toml"*)
crate_symbols=$crate_symbols"L"
;;
*"cargo-make/cargo-leptos-test.toml"*)
crate_symbols=$crate_symbols"L"
if [ $pw_count -gt 0 ]; then
crate_symbols=$crate_symbols"P"
fi
;;
esac
done <"./Makefile.toml"
# Sort list of tools
sorted_crate_symbols=$(echo ${crate_symbols} | grep -o . | sort | tr -d "\n")
formatted_crate_symbols="${BOLD}${YELLOW}${sorted_crate_symbols}${RESET}"
crate_line=$path
if [ ! -z ${1+x} ]; then
# Show all examples
if [ ! -z $crate_symbols ]; then
crate_line=$crate_line$formatted_crate_symbols
fi
echo $crate_line
elif [ ! -z $crate_symbols ]; then
# Filter out examples that do not run tests in `ci`
crate_line=$crate_line$formatted_crate_symbols
echo $crate_line
fi
cd ${start_path}
done
c="${BOLD}${YELLOW}C${RESET} = Cucumber"
d="${BOLD}${YELLOW}D${RESET} = WebDriver"
l="${BOLD}${YELLOW}L${RESET} = Cargo Leptos"
n="${BOLD}${YELLOW}N${RESET} = Node"
p="${BOLD}${YELLOW}P${RESET} = Playwright"
t="${BOLD}${YELLOW}T${RESET} = Trunk"
w="${BOLD}${YELLOW}W${RESET} = WASM"
echo
echo "${ITALIC}Keys:${RESET} $c, $d, $l, $n, $p, $t, $w"
echo
'''
[tasks.post-web-test]

View File

@@ -1,45 +0,0 @@
# Examples README
## Main Branch
The examples in this directory are all built and tested against the current `main` branch.
To the extent that new features have been released or breaking changes have been made since the previous release, the examples are compatible with the `main` branch but not the current release.
To see the examples as they were at the time of the `0.5.0` release, [click here](https://github.com/leptos-rs/leptos/tree/v0.5.0/examples).
## Cargo Make
[Cargo Make](https://sagiegurari.github.io/cargo-make/) is used to build, test, and run examples.
Here are the highlights.
- Extendable custom task files are located in the [cargo-make](./cargo-make/) directory
- Running a task will automatically install `cargo` dependencies
- Each `Makefile.toml` file must extend the [cargo-make/main.toml](./cargo-make/main.toml) file
- [cargo-make](./cargo-make/) files that end in `*-test.toml` configure web testing strategies
- Run `cargo make test-report` to learn which examples have web tests
## Getting Started
Follow these steps to get any example up and running.
1. `cd` to the example root directory
2. Run `cargo make ci` to setup and test the example
3. Run `cargo make start` to run the example
4. Open the client URL in the console output (<http://127.0.0.1:8080> or <http://127.0.0.1:3000> by default)
## Prerequisites
Example projects depend on the following tools. Please install them as needed.
- [Rust](https://www.rust-lang.org/)
- Nightly Rust
- Run `rustup toolchain install nightly`
- Run `rustup target add wasm32-unknown-unknown`
- [Cargo Make](https://sagiegurari.github.io/cargo-make/)
- Run `cargo install --force cargo-make`
- Setup a command alias like `alias cm='cargo make'` to reduce typing (**_Optional_**)
- [Node Version Manager](https://github.com/nvm-sh/nvm/) (**_Optional_**)
- [Node.js](https://nodejs.org/)
- [pnpm](https://pnpm.io/) (**_Optional_**)

View File

@@ -1,68 +0,0 @@
# Server Side Rendering
## Cargo Leptos
cargo-leptos is now the easiest and most featureful way to build server side rendered apps with hydration. It provides automatic recompilation of client and server code, wasm optimisation, CSS minification, and more! Check out more about it [here](https://github.com/akesson/cargo-leptos)
1. Install cargo-leptos
```bash
cargo install --locked cargo-leptos
```
2. Build the site in watch mode, recompiling on file changes
```bash
cargo leptos watch
```
Open browser on [http://localhost:3000/](http://localhost:3000/)
3. When ready to deploy, run
```bash
cargo leptos build --release
```
## WASM Pack
To run it as a server side app with hydration, you'll need to have wasm-pack installed.
0. Edit the `[package.metadata.leptos]` section and set `site-root` to `"."`. For examples with CSS you also want to change the path of the `<StyleSheet / >` component in the root component to point towards the CSS file in the root. This tells leptos that the WASM/JS files generated by wasm-pack are available at `./pkg` and that the CSS files are no longer processed by cargo-leptos. Building to alternative folders is not supported at this time. You'll also want to edit the call to `get_configuration()` to pass in `Some(Cargo.toml)`, so that Leptos will read the settings instead of cargo-leptos. If you do so, your file/folder names cannot include dashes.
1. Install wasm-pack
```bash
cargo install wasm-pack
```
2. Build the Webassembly used to hydrate the HTML from the server
```bash
wasm-pack build --target=web --debug --no-default-features --features=hydrate
```
3. Run the server to serve the Webassembly, JS, and HTML
```bash
cargo run --no-default-features --features=ssr
```
### Server Side Rendering With Hydration
To run it as a server side app with hydration, first you should run
```bash
wasm-pack build --target=web --debug --no-default-features --features=hydrate
```
to generate the WebAssembly to hydrate the HTML delivered from the server.
Then run the server with `cargo run` to serve the server side rendered HTML and the WASM bundle for hydration.
```bash
cargo run --no-default-features --features=ssr
```
> Note that if your hydration code changes, you will have to rerun the wasm-pack command above before running
> `cargo run`

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@@ -1,14 +0,0 @@
[package]
name = "animated-show"
version = "0.1.0"
edition = "2021"
[profile.release]
codegen-units = 1
lto = true
[dependencies]
leptos = { path = "../../leptos", features = ["csr"] }
console_log = "1"
log = "0.4"
console_error_panic_hook = "0.1.7"

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@@ -1,4 +0,0 @@
extend = [
{ path = "../cargo-make/main.toml" },
{ path = "../cargo-make/trunk_server.toml" },
]

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@@ -1,10 +0,0 @@
# Animated Show Example
This is a very simple example of the `<AnimatedShow>` component.
The `<AnimatedShow>` component is an extension for the `<Show>` component and it will not take in a fallback, but it will unmount the component from the DOM after a given duration. This makes it possible to have really easy unmount animations with just
CSS.
## Getting Started
See the [Examples README](../README.md) for setup and run instructions.

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@@ -1,42 +0,0 @@
<!DOCTYPE html>
<html>
<head>
<link data-trunk rel="rust" data-wasm-opt="z"/>
<link data-trunk rel="icon" type="image/ico" href="/public/favicon.ico"/>
<style>
.hover-me {
width: 100px;
margin: 1rem;
padding: 1rem;
text-align: center;
cursor: pointer;
border: 1px solid grey;
}
.here-i-am {
width: 100px;
margin: 1rem;
padding: 1rem;
text-align: center;
color: white;
font-weight: bold;
background: black;
}
@keyframes fade-in {
from { opacity: 0; }
to { opacity: 1; }
}
@keyframes fade-out {
from { opacity: 1; }
to { opacity: 0; }
}
.fade-in-1000 {
animation: 1000ms fade-in forwards;
}
.fade-out-1000 {
animation: 1000ms fade-out forwards;
}
</style>
</head>
<body></body>
</html>

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@@ -1,34 +0,0 @@
use core::time::Duration;
use leptos::*;
#[component]
pub fn App() -> impl IntoView {
let show = create_rw_signal(false);
// the CSS classes in this example are just written directly inside the `index.html`
view! {
<div
class="hover-me"
on:mouseenter=move |_| show.set(true)
on:mouseleave=move |_| show.set(false)
>
"Hover Me"
</div>
<AnimatedShow
when=show
// optional CSS class which will be applied if `when == true`
show_class="fade-in-1000"
// optional CSS class which will be applied if `when == false` and before the
// `hide_delay` starts -> makes CSS unmount animations really easy
hide_class="fade-out-1000"
// the given unmount delay which should match your unmount animation duration
hide_delay=Duration::from_millis(1000)
>
// provide any `Children` inside here
<div class="here-i-am">
"Here I Am!"
</div>
</AnimatedShow>
}
}

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@@ -1,8 +0,0 @@
use animated_show::App;
use leptos::*;
pub fn main() {
_ = console_log::init_with_level(log::Level::Debug);
console_error_panic_hook::set_once();
mount_to_body(App);
}

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@@ -1,4 +0,0 @@
extend = { path = "./cargo-leptos.toml" }
[tasks.integration-test]
dependencies = ["install-cargo-leptos", "cargo-leptos-e2e"]

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@@ -1,7 +0,0 @@
extend = [
{ path = "./cargo-leptos.toml" },
{ path = "../cargo-make/webdriver.toml" },
]
[tasks.integration-test]
dependencies = ["install-cargo-leptos", "start-webdriver", "cargo-leptos-e2e"]

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@@ -1,32 +0,0 @@
[tasks.install-cargo-leptos]
install_crate = { crate_name = "cargo-leptos", binary = "cargo-leptos", test_arg = "--help" }
[tasks.cargo-leptos-e2e]
command = "cargo"
args = ["leptos", "end-to-end"]
[tasks.build]
clear = true
command = "cargo"
args = ["leptos", "build"]
[tasks.check]
clear = true
dependencies = ["check-debug", "check-release"]
[tasks.check-debug]
toolchain = "nightly"
command = "cargo"
args = ["check-all-features"]
install_crate = "cargo-all-features"
[tasks.check-release]
toolchain = "nightly"
command = "cargo"
args = ["check-all-features", "--release"]
install_crate = "cargo-all-features"
[tasks.start-client]
dependencies = ["install-cargo-leptos"]
command = "cargo"
args = ["leptos", "watch"]

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@@ -1,29 +0,0 @@
[tasks.clean]
dependencies = [
"clean-cargo",
"clean-trunk",
"clean-node_modules",
"clean-playwright",
]
[tasks.clean-cargo]
command = "rm"
args = ["-rf", "target"]
[tasks.clean-trunk]
script = '''
find . -type d -name dist | xargs rm -rf
'''
[tasks.clean-node_modules]
script = '''
project_dir=${PWD##*/}
if [ "$project_dir" != "todomvc" ]; then
find . -type d -name node_modules | xargs rm -rf
fi
'''
[tasks.clean-playwright]
script = '''
find . -name playwright-report -name playwright -name test-results | xargs rm -rf
'''

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@@ -1,34 +0,0 @@
[tasks.start-client]
[tasks.stop-client]
condition = { env_set = ["CLIENT_PROCESS_NAME"] }
script = '''
if [ ! -z $(pidof ${CLIENT_PROCESS_NAME}) ]; then
pkill -ef ${CLIENT_PROCESS_NAME}
fi
'''
[tasks.client-status]
condition = { env_set = ["CLIENT_PROCESS_NAME"] }
script = '''
if [ -z $(pidof ${CLIENT_PROCESS_NAME}) ]; then
echo " ${CLIENT_PROCESS_NAME} is not running"
else
echo " ${CLIENT_PROCESS_NAME} is up"
fi
'''
[tasks.maybe-start-client]
condition = { env_set = ["CLIENT_PROCESS_NAME"] }
script = '''
if [ -z $(pidof ${CLIENT_PROCESS_NAME}) ]; then
echo " Starting ${CLIENT_PROCESS_NAME}"
if [ -z ${SPAWN_CLIENT_PROCESS} ];then
cargo make start-client ${@} &
else
cargo make start-client ${@}
fi
else
echo " ${CLIENT_PROCESS_NAME} is already started"
fi
'''

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