chore: clear clippy warnings

The modulo operator is less of a head-scratcher for folks coming through here. The bitwise & is equally correct (clearly) but is likely to cause confusion if folks don't immediately see what's going on.

.github/workflows/check-examples.yml

@@ -0,0 +1,45 @@
+name: Test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  test:
+    name: Check examples ${{ 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 examples
+        run: cargo make check-examples

.github/workflows/check-stable.yml

@@ -0,0 +1,45 @@
+name: Test
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  test:
+    name: Check examples ${{ matrix.os }} (using rustc ${{ matrix.rust }})
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        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 check-stable

.github/workflows/check.yml

@@ -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 check

.github/workflows/fmt.yml

@@ -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

.github/workflows/test.yml

@@ -11,7 +11,7 @@ env:
 
 jobs:
   test:
-    name: Test on ${{ matrix.os }} (using rustc ${{ matrix.rust }})
+    name: Run tests ${{ matrix.os }} (using rustc ${{ matrix.rust }})
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -30,17 +30,16 @@ jobs:
           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
 
-      - name: Run Rustfmt
-        run: cargo fmt -- --check
-
       - uses: Swatinem/rust-cache@v2
 
       - name: Run tests with all features
-        run: cargo make ci
-
+        run: cargo make test

Cargo.toml

@@ -4,13 +4,19 @@ members = [
   "leptos",
   "leptos_dom",
   "leptos_config",
+  "leptos_hot_reload",
   "leptos_macro",
   "leptos_reactive",
   "leptos_server",
+  "server_fn",
+  "server_fn_macro",
+  "server_fn/server_fn_macro_default",
 
   # integrations
   "integrations/actix",
   "integrations/axum",
+  "integrations/viz",
+  "integrations/utils",
 
   # libraries
   "meta",
@@ -19,17 +25,22 @@ members = [
 exclude = ["benchmarks", "examples"]
 
 [workspace.package]
-version = "0.1.3"
+version = "0.2.4"
 
 [workspace.dependencies]
-leptos = { path = "./leptos", default-features = false, version = "0.1.3" }
-leptos_dom = { path = "./leptos_dom", default-features = false, version = "0.1.3" }
-leptos_macro = { path = "./leptos_macro", default-features = false, version = "0.1.3" }
-leptos_reactive = { path = "./leptos_reactive", default-features = false, version = "0.1.3" }
-leptos_server = { path = "./leptos_server", default-features = false, version = "0.1.3" }
-leptos_config = { path = "./leptos_config", default-features = false, version = "0.1.3" }
-leptos_router = { path = "./router", version = "0.1.3" }
-leptos_meta = { path = "./meta", default-feature = false, version = "0.1.3" }
+leptos = { path = "./leptos", default-features = false, version = "0.2.4" }
+leptos_dom = { path = "./leptos_dom", default-features = false, version = "0.2.4" }
+leptos_hot_reload = { path = "./leptos_hot_reload", version = "0.2.4" }
+leptos_macro = { path = "./leptos_macro", default-features = false, version = "0.2.4" }
+leptos_reactive = { path = "./leptos_reactive", default-features = false, version = "0.2.4" }
+leptos_server = { path = "./leptos_server", default-features = false, version = "0.2.4" }
+server_fn = { path = "./server_fn", default-features = false, version = "0.2.4" }
+server_fn_macro = { path = "./server_fn_macro", default-features = false, version = "0.2.4" }
+server_fn_macro_default = { path = "./server_fn/server_fn_macro_default", default-features = false, version = "0.2.4" }
+leptos_config = { path = "./leptos_config", default-features = false, version = "0.2.4" }
+leptos_router = { path = "./router", version = "0.2.4" }
+leptos_meta = { path = "./meta", default-feature = false, version = "0.2.4" }
+leptos_integration_utils = { path = "./integrations/utils", version = "0.2.4" }
 
 [profile.release]
 codegen-units = 1

Makefile.toml

@@ -7,38 +7,65 @@
 # make tasks run at the workspace root
 default_to_workspace = false
 
-[tasks.ci]
-dependencies = ["build", "check-examples", "test"]
-
-[tasks.build]
+[tasks.check]
 clear = true
-dependencies = ["build-all"]
+dependencies = [
+	"check-all",
+	"check-wasm",
+	"check-all-release",
+	"check-wasm-release",
+]
 
-[tasks.build-all]
+[tasks.check-all]
 command = "cargo"
-args = ["+nightly", "build-all-features"]
+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/counter_without_macros" },
 	{ name = "check", path = "examples/counters" },
-	{ name = "check", path = "examples/counters_stable" },
+	{ 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/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]
+clear = true
+dependencies = [
+	{ name = "check", path = "examples/counter_without_macros" },
+	{ name = "check", path = "examples/counters_stable" },
+]
+
 [tasks.test]
 clear = true
 dependencies = ["test-all"]

README.md

@@ -78,7 +78,7 @@ rustup target add wasm32-unknown-unknown
 
 If you’re on `stable`, note the following:
 
-1. You need to enable the `"stable"` flag in `Cargo.toml`: `leptos = { version = "0.1.0-alpha", features = ["stable"] }`
+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 you’re using `stable`,
    you’ll 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)
@@ -99,6 +99,10 @@ Open browser on [http://localhost:3000/](http://localhost:3000/)
 
 ## FAQs
 
+### What’s up with the name?
+
+*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?
 
 People usually mean one of three things by this question.

benchmarks/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+l021 = { package = "leptos", version = "0.2.1" }
 leptos = { path = "../leptos", default-features = false, features = ["ssr"] }
 sycamore = { version = "0.8", features = ["ssr"] }
 yew = { git = "https://github.com/yewstack/yew", features = ["ssr"] }
@@ -27,4 +28,4 @@ features = [
 	"Document",
 	"HtmlElement",
 	"HtmlInputElement"
-]
+]

benchmarks/src/lib.rs

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

benchmarks/src/reactive.rs

@@ -1,35 +1,114 @@
+use std::{cell::Cell, rc::Rc};
 use test::Bencher;
 
-use std::{cell::Cell, rc::Rc};
-
 #[bench]
-fn leptos_create_1000_signals(b: &mut Bencher) {
-    use leptos::{create_isomorphic_effect, create_memo, create_scope, create_signal};
+fn leptos_deep_creation(b: &mut Bencher) {
+    use leptos::*;
+    let runtime = create_runtime();
 
     b.iter(|| {
-        create_scope(|cx| {
-            let acc = Rc::new(Cell::new(0));
-            let sigs = (0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>();
+        create_scope(runtime, |cx| {
+            let signal = create_rw_signal(cx, 0);
+            let mut memos = Vec::<Memo<usize>>::new();
+            for i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+        })
+        .dispose()
+    });
+
+    runtime.dispose();
+}
+
+#[bench]
+fn leptos_deep_update(b: &mut Bencher) {
+    use leptos::*;
+    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 i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+            signal.set(1);
+            assert_eq!(memos[999].get(), 1001);
+        })
+        .dispose()
+    });
+
+    runtime.dispose();
+}
+
+#[bench]
+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>());
+            let memo = create_memo(cx, move |_| {
+                reads.iter().map(|r| r.get()).sum::<i32>()
+            });
             assert_eq!(memo(), 499500);
         })
         .dispose()
     });
+
+    runtime.dispose();
 }
 
 #[bench]
-fn leptos_create_and_update_1000_signals(b: &mut Bencher) {
-    use leptos::{create_isomorphic_effect, create_memo, create_scope, create_signal};
+fn leptos_fanning_out(b: &mut Bencher) {
+    use leptos::*;
+    let runtime = create_runtime();
 
     b.iter(|| {
-        create_scope(|cx| {
+        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 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>());
+            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);
@@ -48,17 +127,20 @@ fn leptos_create_and_update_1000_signals(b: &mut Bencher) {
         })
         .dispose()
     });
+
+    runtime.dispose();
 }
 
 #[bench]
-fn leptos_create_and_dispose_1000_scopes(b: &mut Bencher) {
-    use leptos::{create_isomorphic_effect, create_scope, create_signal};
+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({
+                create_scope(runtime, {
                     let acc = Rc::clone(&acc);
                     move |cx| {
                         let (r, w) = create_signal(cx, 0);
@@ -76,16 +158,183 @@ fn leptos_create_and_dispose_1000_scopes(b: &mut Bencher) {
             disposer.dispose();
         }
     });
+
+    runtime.dispose();
 }
 
 #[bench]
-fn sycamore_create_1000_signals(b: &mut Bencher) {
-    use sycamore::reactive::{create_effect, create_memo, create_scope, create_signal};
+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 i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+        })
+        .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 i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+            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(|| {
+        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);
+        })
+        .dispose()
+    });
+
+    runtime.dispose();
+}
+
+#[bench]
+fn l021_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 l021_narrowing_update(b: &mut Bencher) {
+    use l021::*;
+    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 l021_scope_creation_and_disposal(b: &mut Bencher) {
+    use l021::*;
+    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 sycamore_narrowing_down(b: &mut Bencher) {
+    use sycamore::reactive::{
+        create_effect, create_memo, create_scope, create_signal,
+    };
 
     b.iter(|| {
         let d = create_scope(|cx| {
             let acc = Rc::new(Cell::new(0));
-            let sigs = Rc::new((0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>());
+            let sigs = Rc::new(
+                (0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>(),
+            );
             let memo = create_memo(cx, {
                 let sigs = Rc::clone(&sigs);
                 move || sigs.iter().map(|r| *r.get()).sum::<i32>()
@@ -97,13 +346,80 @@ fn sycamore_create_1000_signals(b: &mut Bencher) {
 }
 
 #[bench]
-fn sycamore_create_and_update_1000_signals(b: &mut Bencher) {
-    use sycamore::reactive::{create_effect, create_memo, create_scope, create_signal};
+fn sycamore_fanning_out(b: &mut Bencher) {
+    use sycamore::reactive::{
+        create_effect, create_memo, create_scope, create_signal,
+    };
+
+    b.iter(|| {
+        let d = create_scope(|cx| {
+            let sig = create_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);
+        });
+        unsafe { d.dispose() };
+    });
+}
+
+#[bench]
+fn sycamore_deep_creation(b: &mut Bencher) {
+    use sycamore::reactive::*;
+
+    b.iter(|| {
+        let d = create_scope(|cx| {
+            let signal = create_signal(cx, 0);
+            let mut memos = Vec::<&ReadSignal<usize>>::new();
+            for i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+        });
+        unsafe { d.dispose() };
+    });
+}
+
+#[bench]
+fn sycamore_deep_update(b: &mut Bencher) {
+    use sycamore::reactive::*;
+
+    b.iter(|| {
+        let d = create_scope(|cx| {
+            let signal = create_signal(cx, 0);
+            let mut memos = Vec::<&ReadSignal<usize>>::new();
+            for i in 0..1000usize {
+                let prev = memos.get(i.saturating_sub(1)).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));
+                }
+            }
+            signal.set(1);
+            assert_eq!(*memos[999].get(), 1001);
+        });
+        unsafe { d.dispose() };
+    });
+}
+#[bench]
+fn sycamore_narrowing_update(b: &mut Bencher) {
+    use sycamore::reactive::{
+        create_effect, create_memo, create_scope, create_signal,
+    };
 
     b.iter(|| {
         let d = create_scope(|cx| {
             let acc = Rc::new(Cell::new(0));
-            let sigs = Rc::new((0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>());
+            let sigs = Rc::new(
+                (0..1000).map(|n| create_signal(cx, n)).collect::<Vec<_>>(),
+            );
             let memo = create_memo(cx, {
                 let sigs = Rc::clone(&sigs);
                 move || sigs.iter().map(|r| *r.get()).sum::<i32>()
@@ -129,7 +445,7 @@ fn sycamore_create_and_update_1000_signals(b: &mut Bencher) {
 }
 
 #[bench]
-fn sycamore_create_and_dispose_1000_scopes(b: &mut Bencher) {
+fn sycamore_scope_creation_and_disposal(b: &mut Bencher) {
     use sycamore::reactive::{create_effect, create_scope, create_signal};
 
     b.iter(|| {

docs/book/.gitignore

@@ -0,0 +1 @@
+book

docs/book/src/02_getting_started.md

@@ -1,13 +1,13 @@
 # Getting Started
 
 There are two basic paths to getting started with Leptos:
+
 1. Client-side rendering with [Trunk](https://trunkrs.dev/)
 2. Full-stack rendering with [`cargo-leptos`](https://github.com/leptos-rs/cargo-leptos)
 
 For the early examples, it will be easiest to begin with Trunk. We’ll introduce
 `cargo-leptos` a little later in this series.
 
-
 If you don’t already have it installed, you can install Trunk by running
 
 ```bash
@@ -20,12 +20,22 @@ Create a basic Rust binary project
 cargo init leptos-tutorial
 ```
 
-`cd` into your new `leptos-tutorial` project and add `leptos` as a dependency 
+> 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
+> ```
+
+`cd` into your new `leptos-tutorial` project and add `leptos` as a dependency
+
 ```bash
 cargo add leptos
 ```
 
 Create a simple `index.html` in the root of the `leptos-tutorial` directory
+
 ```html
 <!DOCTYPE html>
 <html>
@@ -35,14 +45,26 @@ Create a simple `index.html` in the root of the `leptos-tutorial` directory
 ```
 
 And add a simple “Hello, world!” to your `main.rs`
-```rust 
+
+```rust
 use leptos::*;
 
 fn main() {
-    mount_to_body(|_cx| view! { cx,  <p>"Hello, world!"</p> })
+    mount_to_body(|cx| view! { cx,  <p>"Hello, world!"</p> })
 }
 ```
 
-Now run `trunk serve --open`. Trunk should automatically compile your app and 
-open it in your default browser. If you make edits to `main.rs`, Trunk will 
-recompile your source code and live-reload the page.
+Your directory structure should now look something like this
+
+```
+leptos_tutorial
+├── src
+│   └── main.rs
+├── Cargo.toml
+├── index.html
+```
+
+Now run `trunk serve --open` from the root of the `leptos-tutorial` directory.
+Trunk should automatically compile your app and open it in your default browser.
+If you make edits to `main.rs`, Trunk will recompile your source code and
+live-reload the page.

docs/book/src/14_create_effect.md

@@ -0,0 +1,110 @@
+# Responding to Changes with `create_effect`
+
+Believe it or not, we’ve 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 there’s 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 you’re 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 don’t 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 don’t need to maintain a dependency list, or worry about what should or shouldn’t 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 they’re 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 you’re doing within them, effects are a zero-cost abstraction. They rerun the absolute minimum number of times necessary, given how you’ve described them.
+
+Imagine that I’m 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: don’t 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 you’re curious for more information about when you should and shouldn’t use `create_effect`, [check out this video](https://www.youtube.com/watch?v=aQOFJQ2JkvQ) for a more in-depth consideration!
+
+## Effects and Rendering
+
+We’ve managed to get this far without mentioning effects because they’re built into the Leptos DOM renderer. We’ve 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 signal’s 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.
+
+<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"></iframe>

docs/book/src/15_global_state.md

@@ -0,0 +1,171 @@
+# 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
+
+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: Passing 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.
+
+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(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(cx, 0);
+    // we'll pass the setter to specific components,
+    // but provide the count itself to the whole app via context
+    provide_context(cx, count);
+
+    view! { cx,
+        // 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
+        <FancyMath/>
+        <ListItems/>
+    }
+}
+```
+
+`<SetterButton/>` is the kind of counter we’ve written several times now.
+(See the sandbox below if you don’t understand what I mean.)
+
+`<FancyMath/>` and `<ListItems/>` both consume the signal we’re providing via
+`use_context` and do something with it.
+
+```rust
+/// A component that does some "fancy" math with the global count
+#[component]
+fn FancyMath(cx: Scope) -> impl IntoView {
+    // here we consume the global count signal with `use_context`
+    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! { cx,
+        <div class="consumer blue">
+            "The number "
+            <strong>{count}</strong>
+            {move || if is_even() {
+                " is"
+            } else {
+                " is not"
+            }}
+            " even."
+        </div>
+    }
+}
+```
+
+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 descendents: 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(Default, Clone, Debug)]
+struct GlobalState {
+    count: u32,
+    name: String,
+}
+```
+
+Provide it in the root of your app so it’s available everywhere.
+
+```rust
+#[component]
+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);
+
+    // ...
+```
+
+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(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
+        |state| state.count,
+        // our setter describes how to mutate that slice, given a new value
+        |state, n| state.count = n,
+    );
+
+    view! { cx,
+        <div class="consumer blue">
+            <button
+                on:click=move |_| {
+                    set_count(count() + 1);
+                }
+            >
+                "Increment Global Count"
+            </button>
+            <br/>
+            <span>"Count is: " {count}</span>
+        </div>
+    }
+}
+```
+
+Clicking this button only updates `state.count`, so if we create another slice
+somewhere else that only takes `state.name`, clicking the button won’t 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.
+
+<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">

docs/book/src/SUMMARY.md

@@ -11,27 +11,32 @@
   - [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]()
-- [Interlude: Reactivity and Functions]()
-- [Testing]()
-- [Interlude: Styling — CSS, Tailwind, Style.rs, and more]()
-- [Async]()
-  - [Resource]()
-  - [Suspense]()
-  - [Transition]()
-- [State Management]()
-- [Interlude: Advanced Reactivity]()
-- [Router]()
-  - [Fundamentals]()
-  - [defining `<Routes/>`]()
-  - [`<A/>`]()
+  - [Passing Children to Components](./view/09_component_children.md)
+- [Interlude: Reactivity and Functions](./interlude_functions.md)
+- [Testing](./testing.md)
+- [Async](./async/README.md)
+  - [Loading Data with Resources](./async/10_resources.md)
+  - [Suspense](./async/11_suspense.md)
+  - [Transition](./async/12_transition.md)
+  - [Actions](./async/13_actions.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)
+  - [Nested Routing](./router/17_nested_routing.md)
+  - [Params and Queries](./router/18_params_and_queries.md)
+  - [`<A/>`](./router/19_a.md)
   - [`<Form/>`]()
+- [Interlude: Styling — CSS, Tailwind, Style.rs, and more]()
 - [Metadata]()
 - [SSR]()
   - [Models of SSR]()
   - [`cargo-leptos`]()
   - [Hydration Footguns]()
 - [Request/Response]()
+  - [Extractors]()
+    - [Axum]()
+    - [Actix]()
   - [Headers]()
   - [Cookies]()
 - [Server Functions]()
@@ -39,3 +44,5 @@
   - [Forms]()
   - [`<ActionForm/>`s]()
   - [Turning off WebAssembly]()
+- [Advanced Reactivity]()
+- [Appendix: Optimizing WASM Binary Size]()

docs/book/src/async/10_resources.md

@@ -0,0 +1,53 @@
+# Loading Data with Resources
+
+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 it’s 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 (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`
+
+Here’s an example
+
+```rust
+// our source signal: some synchronous, local state
+let (count, set_count) = create_signal(cx, 0);
+
+// our resource
+let async_data = create_resource(cx,
+    count,
+    // every time `count` changes, this will run
+    |value| async move {
+        log!("loading data from API");
+        load_data(value).await
+    },
+);
+```
+
+To create a resource that simply runs once, you can pass a non-reactive, empty source signal:
+
+```rust
+let once = create_resource(cx, || (), |_| async move { load_data().await });
+```
+
+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 it’s always possible that your resource is still loading.
+2. They take a `Scope` argument. You’ll 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(cx, || (), |_| async move { load_data().await });
+view! { cx,
+    <h1>"My Data"</h1>
+    {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.
+
+<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"></iframe>

docs/book/src/async/11_suspense.md

@@ -0,0 +1,72 @@
+# `<Suspense/>`
+
+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(cx, 0);
+let a = create_resource(cx, count, |count| async move { load_a(count).await });
+
+view! { cx,
+    <h1>"My Data"</h1>
+    {move || match once.read(cx) {
+        None => view! { cx, <p>"Loading..."</p> }.into_view(cx),
+        Some(data) => view! { cx, <ShowData data/> }.into_view(cx)
+    }}
+}
+```
+
+But what if we have two resources, and want to wait for both of them?
+
+```rust
+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! { cx,
+    <h1>"My Data"</h1>
+    {move || match (a.read(cx), b.read(cx)) {
+        _ => view! { cx, <p>"Loading..."</p> }.into_view(cx),
+        (Some(a), Some(b)) => view! { cx,
+            <ShowA a/>
+            <ShowA b/>
+        }.into_view(cx)
+    }}
+}
+```
+
+That’s not _so_ bad, but it’s kind of annoying. What if we could invert the flow of control?
+
+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 it’s still waiting for resources to load, it shows the `fallback`. When they’ve all loaded, it shows the children.
+
+```rust
+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! { cx,
+    <h1>"My Data"</h1>
+    <Suspense
+        fallback=move || view! { cx, <p>"Loading..."</p> }
+    >
+        <h2>"My Data"</h2>
+        <h3>"A"</h3>
+        {move || {
+            a.read(cx)
+                .map(|a| view! { cx, <ShowA a/> })
+        }}
+        <h3>"B"</h3>
+        {move || {
+            b.read(cx)
+                .map(|b| view! { cx, <ShowB b/> })
+        }}
+    </Suspense>
+}
+```
+
+Every time one of the resources is reloading, the `"Loading..."` fallback will show again.
+
+This inversion of the flow of control makes it easier to add or remove individual resources, as you don’t need to handle the matching yourself. It also unlocks some massive performance improvements during server-side rendering, which we’ll talk about during a later chapter.
+
+<iframe src="https://codesandbox.io/p/sandbox/11-suspense-907niv?file=%2Fsrc%2Fmain.rs" width="100%" height="1000px"></iframe>

docs/book/src/async/12_transition.md

@@ -0,0 +1,9 @@
+# `<Transition/>`
+
+You’ll notice in the `<Suspense/>` example that if you keep reloading the data, it keeps flickering back to `"Loading..."`. Sometimes this is fine. For other times, there’s [`<Transition/>`](https://docs.rs/leptos/latest/leptos/fn.Suspense.html).
+
+`<Transition/>` behaves exactly the same as `<Suspense/>`, but instead of falling back every time, it only shows the fallback the first time. On all subsequent loads, it continues showing the old data until the new data are ready. This can be really handy to prevent the flickering effect, and to allow users to continue interacting with your application.
+
+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 laods. This can be a much better user experience than constantly falling back to a loading message.
+
+<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"></iframe>

docs/book/src/async/13_actions.md

@@ -0,0 +1,94 @@
+# Mutating Data with Actions
+
+We’ve talked about how to load `async` data with resources. Resources immediately load data and work closely with `<Suspense/>` and `<Transition/>` components to show whether data is loading in your app. But what if you just want to call some arbitrary `async` function and keep track of what it’s doing?
+
+Well, you could always use [`spawn_local`](https://docs.rs/leptos/latest/leptos/fn.spawn_local.html). This allows you to just spawn an `async` task in a synchronous environment by handing the `Future` off to the browser (or, on the server, Tokio or whatever other runtime you’re using). But how do you know if it’s still pending? Well, you could just set a signal to show whether it’s loading, and another one to show the result...
+
+All of this is true. Or you could use the final `async` primitive: [`create_action`](https://docs.rs/leptos/latest/leptos/fn.create_action.html).
+
+Actions and resources seem similar, but they represent fundamentally different things. If you’re trying to load data by running an `async` function, either once or when some other value changes, you probably want to use `create_resource`. If you’re trying to occasionally run an `async` function in response to something like a user clicking a button, you probably want to use `create_action`.
+
+Say we have some `async` function we want to run.
+
+```rust
+async fn add_todo(new_title: &str) -> Uuid {
+    /* do some stuff on the server to add a new todo */
+}
+```
+
+`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(cx, |input: &String| {
+>    let input = input.clone();
+>    async move { todo!() }
+> });
+>
+> // if there are no arguments, use the unit type `()`
+> let action2 = create_action(cx, |input: &()| async { todo!() });
+>
+> // if there are multiple arguments, use a tuple
+> let action3 = create_action(cx,
+>   |input: &(usize, String)| async { todo!() }
+> );
+> ```
+>
+> Because the action function takes a reference but the `Future` needs to have a `'static` lifetime, you’ll usually need to clone the value to pass it into the `Future`. This is admittedly awkward but it unlocks some powerful features like optimistic UI. We’ll see a little more about that in future chapters.
+
+So in this case, all we need to do to create an action is
+
+```rust
+let add_todo = create_action(cx, |input: &String| {
+    let input = input.to_owned();
+    async move { add_todo(&input).await }
+});
+```
+
+Rather than calling `add_todo` directly, we’ll call it with `.dispatch()`, as in
+
+```rust
+add_todo.dispatch("Some value".to_string());
+```
+
+You can do this from an event listener, a timeout, or anywhere; because `.dispatch()` isn’t an `async` function, it can be called from a synchronous context.
+
+Actions provide access to a few signals that synchronize between the asynchronous action you’re calling and the synchronous reactive system:
+
+```rust
+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>(cx);
+
+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.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>
+    // use our loading state
+    <p>{move || pending().then("Loading...")}</p>
+}
+```
+
+Now, there’s 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, you’ll 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... Don’t 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.)
+
+<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"></iframe>

docs/book/src/async/README.md

@@ -0,0 +1,9 @@
+# Working with `async`
+
+So far we’ve only been working with synchronous users interfaces: You provide some input,
+the app immediately process it and updates the interface. This is great, but is a tiny
+subset of what web applications do. In particular, most web apps have to deal with some kind
+of asynchronous data loading, usually loading something from an API.
+
+Asynchronous data is notoriously hard to integrate with the synchronous parts of your code.
+In this chapter, we’ll see how Leptos helps smooth out that process for you.

docs/book/src/interlude_functions.md

@@ -0,0 +1,76 @@
+# Interlude: Reactivity and Functions
+
+One of our core contributors said to me recently: “I never used closures this often
+until I started using Leptos.” And it’s true. Closures are at the heart of any Leptos
+application. It sometimes looks a little silly:
+
+```rust
+// a signal holds a value, and can be updated
+let (count, set_count) = create_signal(cx, 0);
+
+// a derived signal is a function that accesses other signals
+let double_count = move || count() * 2;
+let count_is_odd = move || count() & 1 == 1;
+let text = move || if count_is_odd() {
+    "odd"
+} else {
+    "even"
+};
+
+// an effect automatically tracks the signals it depends on
+// and reruns when they change
+create_effect(cx, move |_| {
+    log!("text = {}", text());
+});
+
+view! { cx,
+    <p>{move || text().to_uppercase()}</p>
+}
+```
+
+Closures, closures everywhere!
+
+But why?
+
+## Functions and UI Frameworks
+
+Functions are at the heart of every UI framework. And this makes perfect sense. Creating a user interface is basically divided into two phases:
+
+1. initial rendering
+2. updates
+
+In a web framework, the framework does some kind of initial rendering. Then it hands control back over to the browser. When certain events fire (like a mouse click) or asynchronous tasks finish (like an HTTP request finishing), the browser wakes the framework back up to update something. The framework runs some kind of code to update your user interface, and goes back asleep until the browser wakes it up again.
+
+The key phrase here is “runs some kind of code.” The natural way to “run some kind of code” at an arbitrary point in time—in Rust or in any other programming language—is to call a function. And in fact every UI framework is based on rerunning some kind of function over and over:
+
+1. virtual DOM (VDOM) frameworks like React, Yew, or Dioxus rerun a component or render function over and over, to generate a virtual DOM tree that can be reconciled with the previous result to patch the DOM
+2. compiled frameworks like Angular and Svelte divide your component templates into “create” and “update” functions, rerunning the update function when they detect a change to the component’s state
+3. in fine-grained reactive frameworks like SolidJS, Sycamore, or Leptos, _you_ define the functions that rerun
+
+That’s what all our components are doing.
+
+Take our typical `<SimpleCounter/>` example in its simplest form:
+
+```rust
+#[component]
+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! { cx,
+        <button on:click=increment>
+            {value}
+        </button>
+    }
+}
+```
+
+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 responsive to a change.
+
+So remember two things:
+
+1. Your component function is a setup function, not a render function: it only runs once.
+2. For values in your view template to be reactive, they must be functions: either signals (which implement the `Fn` traits) or closures.

docs/book/src/router/16_routes.md

@@ -0,0 +1,101 @@
+# Defining Routes
+
+## Getting Started
+
+It’s easy to get started with the router.
+
+First things first, make sure you’ve added the `leptos_router` package to your dependencies.
+
+> It’s important that the router is a separate package from `leptos` itself. This means that everything in the router can be defined in user-land code. If you want to create your own router, or use no router, you’re completely free to do that!
+
+And import the relevant types from the router, either with something like
+
+```rust
+use leptos_router::{Route, RouteProps, Router, RouterProps, Routes, RoutesProps};
+```
+
+or simply
+
+```rust
+use leptos_router::*;
+```
+
+## Providing the `<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 shouldn’t 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?
+
+Let’s start with a simple `<App/>` component using the router:
+
+```rust
+use leptos::*;
+use leptos_router::*;
+
+#[component]
+pub fn App(cx: Scope) -> impl IntoView {
+  view! {
+    <Router>
+      <nav>
+        /* ... */
+      </nav>
+      <main>
+        /* ... */
+      </main>
+    </Router>
+  }
+}
+```
+
+## Defining `<Routes/>`
+
+The [`<Routes/>`](https://docs.rs/leptos_router/latest/leptos_router/fn.Routes.html) component is where you define all the routes to which a user can navigate in your application. Each possible route is defined by a [`<Route/>`](https://docs.rs/leptos_router/latest/leptos_router/fn.Route.html) component.
+
+You should place the `<Routes/>` component at the location within your app where you want routes to be rendered. Everything outside `<Routes/>` will be present on every page, so you can leave things like a navigation bar or menu outside the `<Routes/>`.
+
+```rust
+use leptos::*;
+use leptos_router::*;
+
+#[component]
+pub fn App(cx: Scope) -> impl IntoView {
+  view! {
+    <Router>
+      <nav>
+        /* ... */
+      </nav>
+      <main>
+        // all our routes will appear inside <main>
+        <Routes>
+          /* ... */
+        </Routes>
+      </main>
+    </Router>
+  }
+}
+```
+
+Individual routes are defined by providing children to `<Routes/>` with the `<Route/>` component. `<Route/>` takes a `path` and a `view`. When the current location matches `path`, the `view` will be created and displayed.
+
+The `path` can include
+
+- a static path (`/users`),
+- dynamic, named parameters beginning with a colon (`/:id`),
+- and/or a wildcard beginning with an asterisk (`/user/*any`)
+
+The `view` is a function that takes a `Scope` and returns a view.
+
+```rust
+<Routes>
+  <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>
+```
+
+> 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` you’ll get the home page or the `<Users/>`. If you go to `/users/3` or `/blahblah` you’ll 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.
+
+Simple enough?

docs/book/src/router/17_nested_routing.md

@@ -0,0 +1,170 @@
+# Nested Routing
+
+We just defined the following set of routes:
+
+```rust
+<Routes>
+  <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>
+```
+
+There’s a certain amount of duplication here: `/users` and `/users/:id`. This is fine for a small app, but you can probably already tell it won’t scale well. Wouldn’t it be nice if we could nest these routes?
+
+Well... you can!
+
+```rust
+<Routes>
+  <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=|cx| view! { cx, <NotFound /> }/>
+</Routes>
+```
+
+But wait. We’ve just subtly changed what our application does.
+
+The next section is one of the most important in this entire routing section of the guide. Read it carefully, and feel free to ask questions if there’s anything you don’t understand.
+
+# Nested Routes as Layout
+
+Nested routes are a form of layout, not a method of route definition.
+
+Let me put that another way: The goal of defining nested routes is not primarily to avoid repeating yourself when typing out the paths in your route definitions. It is actually to tell the router to display multiple `<Route/>`s on the page at the same time, side by side.
+
+Let’s look back at our practical example.
+
+```rust
+<Routes>
+  <Route path="/users" view=|cx| view! { cx, <Users /> }/>
+  <Route path="/users/:id" view=|cx| view! { cx, <UserProfile /> }/>
+</Routes>
+```
+
+This means:
+
+- If I go to `/users`, I get the `<Users/>` component.
+- If I go to `/users/3`, I get the `<UserProfile/>` component (with the parameter `id` set to `3`; more on that later)
+
+Let’s say I use nested routes instead:
+
+```rust
+<Routes>
+  <Route path="/users" view=|cx| view! { cx, <Users /> }>
+    <Route path=":id" view=|cx| view! { cx, <UserProfile /> }/>
+  </Route>
+</Routes>
+```
+
+This means:
+
+- If I go to `/users/3`, the path matches two `<Route/>`s: `<Users/>` and `<UserProfile/>`.
+- If I go to `/users`, the path is not matched.
+
+I actually need to add a fallback route
+
+```rust
+<Routes>
+  <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>
+```
+
+Now:
+
+- If I go to `/users/3`, the path matches `<Users/>` and `<UserProfile/>`.
+- If I go to `/users`, the path matches `<Users/>` and `<NoUser/>`.
+
+When I use nested routes, in other words, each **path** can match multiple **routes**: each URL can render the views provided by multiple `<Route/>` components, at the same time, on the same page.
+
+This may be counter-intuitive, but it’s very powerful, for reasons you’ll hopefully see in a few minutes.
+
+## Why Nested Routing?
+
+Why bother with this?
+
+Most web applications contain levels of navigation that correspond to different parts of the layout. For example, in an email app you might have a URL like `/contacts/greg`, which shows a list of contacts on the left of the screen, and contact details for Greg on the right of the screen. The contact list and the contact details should always appear on the screen at the same time. If there’s no contact selected, maybe you want to show a little instructional text.
+
+You can easily define this with nested routes
+
+```rust
+<Routes>
+  <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>
+</Routes>
+```
+
+You can go even deeper. Say you want to have tabs for each contact’s address, email/phone, and your conversations with them. You can add _another_ set of nested routes inside `:id`:
+
+```rust
+<Routes>
+  <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=|cx| view! { cx,
+      <p>"Select a contact to view more info."</p>
+    }/>
+  </Route>
+</Routes>
+```
+
+> The main page of the [Remix website](https://remix.run/), a React framework from the creators of React Router, has a great visual example if you scroll down, with three levels of nested routing: Sales > Invoices > an invoice.
+
+## `<Outlet/>`
+
+Parent routes do not automatically render their nested routes. After all, they are just components; they don’t 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:
+
+- if there is no nested route that has been matched, it shows nothing
+- if there is a nested route that has been matched, it shows its `view`
+
+That’s all! But it’s important to know and to remember, because it’s a common source of “Why isn’t this working?” frustration. If you don’t provide an `<Outlet/>`, the nested route won’t be displayed.
+
+```rust
+#[component]
+pub fn ContactList(cx: Scope) -> impl IntoView {
+  let contacts = todo!();
+
+  view! { cx,
+    <div style="display: flex">
+      // the contact list
+      <For each=contacts
+        key=|contact| contact.id
+        view=|cx, contact| todo!()
+      >
+      // the nested child, if any
+      // don’t forget this!
+      <Outlet/>
+    </div>
+  }
+}
+```
+
+## Nested Routing and Performance
+
+All of this is nice, conceptually, but again—what’s the big deal?
+
+Performance.
+
+In a fine-grained reactive library like Leptos, it’s always important to do the least amount of rendering work you can. Because we’re working with real DOM nodes and not diffing a virtual DOM, we want to “rerender” components as infrequently as possible. Nested routing makes this extremely easy.
+
+Imagine my contact list example. If I navigate from Greg to Alice to Bob and back to Greg, the contact information needs to change on each navigation. But the `<ContactList/>` should never be rerendered. Not only does this save on rendering performance, it also maintains state in the UI. For example, if I have a search bar at the top of `<ContactList/>`, navigating from Greg to Alice to Bob won’t clear the search.
+
+In fact, in this case, we don’t even need to rerender the `<Contact/>` component when moving between contacts. The router will just reactively update the `:id` parameter as we navigate, allowing us to make fine-grained updates. As we navigate between contacts, we’ll update single text nodes to change the contact’s name, address, and so on, without doing _any_ additional rerendering.
+
+> This sandbox includes a couple features (like nested routing) discussed in this section and the previous one, and a couple we’ll cover in the rest of this chapter. The router is such an integrated system that it makes sense to provide a single example, so don’t be surprised if there’s anything you don’t understand.
+
+<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"></iframe>

docs/book/src/router/18_params_and_queries.md

@@ -0,0 +1,77 @@
+# Params and Queries
+
+Static paths are useful for distinguishing between different pages, but almost every application wants to pass data through the URL at some point.
+
+There are two ways you can do this:
+
+1. named route **params** like `id` in `/users/:id`
+2. named route **queries** like `q` in `/search?q=Foo`
+
+Because of the way URLs are built, you can access the query from _any_ `<Route/>` view. You can access route params from the `<Route/>` that defines them or any of its nested children.
+
+Accessing params and queries is pretty simple with a couple of hooks:
+
+- [`use_query`](https://docs.rs/leptos_router/latest/leptos_router/fn.use_query.html) or [`use_query_map`](https://docs.rs/leptos_router/latest/leptos_router/fn.use_query_map.html)
+- [`use_params`](https://docs.rs/leptos_router/latest/leptos_router/fn.use_params.html) or [`use_params_map`](https://docs.rs/leptos_router/latest/leptos_router/fn.use_query_map.html)
+
+Each of these comes with a typed option (`use_query` and `use_params`) and an untyped option (`use_query_map` and `use_params_map`).
+
+The untyped versions hold a simple key-value map. To use the typed versions, derive the [`Params`](https://docs.rs/leptos_router/0.2.3/leptos_router/trait.Params.html) trait on a struct.
+
+> `Params` is a very lightweight trait to convert a flat key-value map of strings into a struct by applying `FromStr` to each field. Because of the flat structure of route params and URL queries, it’s significantly less flexible than something like `serde`; it also adds much less weight to your binary.
+
+```rust
+use leptos::*;
+use leptos_router::*;
+
+#[derive(Params)]
+struct ContactParams {
+	id: usize
+}
+
+#[derive(Params)]
+struct ContactSearch {
+	q: String
+}
+```
+
+> 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 you’re importing the right one for the derive macro.
+
+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>, _>`. It’s a Memo so it reacts to changes in the URL. It’s 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>(cx);
+let query = use_query::<ContactSearch>(cx);
+
+// id: || -> usize
+let id = move || {
+	params.with(|params| {
+		params
+			.map(|params| params.id)
+			.unwrap_or_default()
+	})
+};
+```
+
+The untyped versions return `Memo<ParamsMap>`. Again, it’s 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::<ContactParams>(cx);
+let query = use_query::<ContactSearch>(cx);
+
+// id: || -> Option<String>
+let id = move || {
+	params.with(|params| params.get("id").cloned())
+};
+```
+
+This can get a little messy: deriving a signal that wraps an `Option<_>` or `Result<_>` can involve a couple steps. But it’s worth doing this for two reasons:
+
+1. It’s correct, i.e., it forces you to consider the cases, “What if the user doesn’t pass a value for this query field? What if they pass an invalid value?”
+2. It’s 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 haven’t explain them all yet.
+
+<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"></iframe>

docs/book/src/router/19_a.md

@@ -0,0 +1,21 @@
+# The `<A/>` Component
+
+Client-side navigation works perfectly fine with ordinary HTML `<a>` elements. The router adds a listener that handles every click on a `<a>` element and tries to handle it on the client side, i.e., without doing another round trip to the server to request HTML. This is what enables the snappy “single-page app” navigations you’re probably familiar with from most modern web apps.
+
+The router will bail out of handling an `<a>` click under a number of situations
+
+- the click event has had `prevent_default()` called on it
+- the <kbd>Meta</kbd>, <kbd>Alt</kbd>, <kbd>Ctrl</kbd>, or <kbd>Shift</kbd> keys were held during click
+- the `<a>` has a `target` or `download` attribute, or `rel="external"`
+- the link has a different origin from the current location
+
+In other words, the router will only try to do a client-side navigation when it’s pretty sure it can handle it, and it will upgrade every `<a>` element to get this special behavior.
+
+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., it’s a link to the page you’re on). This is helpful for accessibility and for styling. For example, if you want to set the link a different color if it’s a link to the page you’re currently on, you can match this attribute with a CSS selector.
+
+> 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.
+
+<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"></iframe>

docs/book/src/router/README.md

@@ -0,0 +1,23 @@
+# Routing
+
+## The Basics
+
+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://leptos.dev/blog/search?q=Search#results` consists of
+
+- a _scheme_: `https`
+- a _domain_: `leptos.dev`
+- a **path**: `/blog/search`
+- a **query** (or **search**): `?q=Search`
+- a _hash_: `#results`
+
+The Leptos Router works with the path and query (`/blog/search?q=Search`). Given this piece of the URL, what should the app render on the page?
+
+## The Philosophy
+
+In most cases, the path should drive what is displayed on the page. From the user’s perspective, for most appliations, most major changes in the state of the app should be reflected in the URL. If you copy and paste the URL and open it in another tab, you should find yourself more or less in the same place.
+
+In this sense, the router is really at the heart of the global state management for your application. More than anything else, it drives what is displayed on the page.
+
+The router handles most of this work for you by mapping the current location to particular components.

docs/book/src/testing.md

@@ -0,0 +1,180 @@
+# Testing Your Components
+
+Testing user interfaces can be relatively tricky, but really important. This article
+will discuss a couple principles and approaches for testing a Leptos app.
+
+## 1. Test business logic with ordinary Rust tests
+
+In many cases, it makes sense to pull the logic out of your components and test
+it separately. For some simple components, there’s no particular logic to test, but
+for many it’s worth using a testable wrapping type and implementing the logic in
+ordinary Rust `impl` blocks.
+
+For example, instead of embedding logic in a component directly like this:
+
+```rust
+#[component]
+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()
+    });
+}
+```
+
+You could pull that logic out into a separate data structure and test it:
+
+```rust
+pub struct Todos(Vec<Todo>);
+
+impl Todos {
+    pub fn num_remaining(&self) -> usize {
+        todos.iter().filter(|todo| !todo.completed).sum()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_remaining {
+        // ...
+    }
+}
+
+#[component]
+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);
+}
+```
+
+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 `wasm-bindgen-test`
+
+[`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.
+
+To use this testing utility, you need to add `wasm-bindgen-test` to your `Cargo.toml`:
+
+```toml
+[dev-dependencies]
+wasm-bindgen-test = "0.3.0"
+```
+
+You should create tests in a separate `tests` directory. You can then run your tests in the browser of your choice:
+
+```bash
+wasm-pack test --firefox
+```
+
+> 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, here’s 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);
+```
+
+I’m 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();
+    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(),
+        |cx| view! { cx, <SimpleCounter initial_value=10 step=1/> },
+    );
+```
+
+We’ll use some manual DOM operations to grab the `<div>` that wraps
+the whole component, as well as the `clear` button.
+
+```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 element’s
+`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(), |cx| {
+            // it's as if we're creating it with a value of 0, right?
+            let (value, set_value) = create_signal(cx, 0);
+
+            // we can remove the event listeners because they're not rendered to HTML
+            view! { cx,
+                <div>
+                    <button>"Clear"</button>
+                    <button>"-1"</button>
+                    <span>"Value: " {value} "!"</span>
+                    <button>"+1"</button>
+                </div>
+            }
+            // the view returned an HtmlElement<Div>, which is a smart pointer for
+            // a DOM element. So we can still just call .outer_html()
+            .outer_html()
+        })
+    );
+```
+
+That test involved us manually replicating the `view` that’s 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: I’ll just test
+the wrapper’s `innerHTML` against another comparison case.
+
+```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()
+    });
+}
+```
+
+This is only a very limited introduction to testing. But I hope it’s useful as you begin to build applications.
+
+> 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).

docs/book/src/view/01_basic_component.md

@@ -31,7 +31,7 @@ fn App(cx: Scope) -> impl IntoView {
                 set_count.update(|n| *n += 1);
             }
         >
-            "Click me"
+            "Click me: "
             {move || count.get()}
         </button>
     }
@@ -61,7 +61,7 @@ Every component is a function with the following characteristics
 
 ## The Component Body
 The body of the component function is a set-up function that runs once, not a 
-render function that re-runs multiple times. You’ll typically use it to create a
+render function that reruns multiple times. You’ll typically use it to create a
 few reactive variables, define any side effects that run in response to those values
 changing, and describe the user interface.
 
@@ -110,7 +110,7 @@ than they’ve ever used in their lives. And fair enough. Basically, passing a f
 into the view tells the framework: “Hey, this is something that might change.”
 
 When we click the button and call `set_count`, the `count` signal is updated. This 
-`move || count.get()` closure, whose value depends on the value of `count`, re-runs, 
+`move || count.get()` closure, whose value depends on the value of `count`, reruns, 
 and the framework makes a targeted update to that one specific text node, touching 
 nothing else in your application. This is what allows for extremely efficient updates
 to the DOM.

docs/book/src/view/02_dynamic_attributes.md

@@ -30,7 +30,7 @@ Now let’s say I’d like to update the list of CSS classes on this element dyn
 For example, let’s say I want to add the class `red` when the count is odd. I can
 do this using the `class:` syntax. 
 ```rust
-class:red=move || count() & 1 == 1
+class:red=move || count() % 2 == 1
 ```
 `class:` attributes take
 1. the class name, following the colon (`red`)

docs/book/src/view/03_components.md

@@ -18,7 +18,7 @@ let double_count = move || count() * 2;
 view! { 
     <progress
         max="50"
-        value=progress
+        value=count
     />
     <progress
         max="50"
@@ -212,7 +212,7 @@ fn ProgressBar<F>(
     progress: F
 ) -> impl IntoView 
 where 
-    F: Fn() -> i32
+    F: Fn() -> i32 + 'static,
 {
     view! { cx,
         <progress
@@ -227,18 +227,18 @@ This is a perfectly reasonable way to write this component: `progress` now takes
 any value that implements this `Fn()` trait.
 
 > Note that generic component props _cannot_ be specified inline (as `<F: Fn() -> i32>`)
-or as `progress: impl Fn() -> i32`, in part because they’re actually used to generate 
+or as `progress: impl Fn() -> i32 + 'static,`, in part because they’re actually used to generate 
 a `struct ProgressBarProps`, and struct fields cannot be `impl` types.
 
 ### `into` Props 
 
 There’s one more way we could implement this, and it would be to use `#[prop(into)]`. 
-This attribute automatically calls `.into()` on the values you pass as proprs,
-which allows you to pass props of different values easily.
+This attribute automatically calls `.into()` on the values you pass as props,
+which allows you to easily pass props with different values.
 
 In this case, it’s helpful to know about the 
 [`Signal`](https://docs.rs/leptos/latest/leptos/struct.Signal.html) type. `Signal`
-is a enumerated type that represents any kind of readable reactive signal. It can 
+is an enumerated type that represents any kind of readable reactive signal. It can 
 be useful when defining APIs for components you’ll want to reuse while passing 
 different sorts of signals. The [`MaybeSignal`](https://docs.rs/leptos/latest/leptos/enum.MaybeSignal.html) type is useful when you want to be able to take either a static or 
 reactive value.

docs/book/src/view/04_iteration.md

@@ -13,7 +13,7 @@ Leptos supports to two different patterns for iterating over items:
 
 Sometimes you need to show an item repeatedly, but the list you’re drawing from 
 does not often change. In this case, it’s important to know that you can insert 
-any `Vec<IV> where IV: IntoView` into your view. In other views, if you can render
+any `Vec<IV> where IV: IntoView` into your view. In other words, if you can render
 `T`, you can render `Vec<T>`.
 
 ```rust
@@ -85,4 +85,4 @@ it is generated, and using that as an ID for the key function.
 
 Check out the `<DynamicList/>` component below for an example.
 
-<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="100px"></iframe>
+<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"></iframe>

docs/book/src/view/05_forms.md

@@ -54,7 +54,7 @@ event.
 ```rust
 let (name, set_name) = create_signal(cx, "Uncontrolled".to_string());
 
-let input_element: NodeRef<HtmlElement<Input>> = NodeRef::new(cx);
+let input_element: NodeRef<Input> = create_node_ref(cx);
 ```
 `NodeRef` is a kind of reactive smart pointer: we can use it to access the 
 underlying DOM node. Its value will be set when the element is rendered.

docs/book/src/view/06_control_flow.md

@@ -26,7 +26,7 @@ things:
    all of which can be rendered. Spending time in the `Option` and `Result` docs in particular
    is one of the best ways to level up your Rust game.
 4. And always remember: to be reactive, values must be functions. You’ll see me constantly
-   wrap things in a `move ||` closure, below. This is to ensure that they actually re-run
+   wrap things in a `move ||` closure, below. This is to ensure that they actually rerun
    when the signal they depend on changes, keeping the UI reactive.
 
 ## So What?
@@ -55,13 +55,13 @@ if it’s even. Well, how about this?
 
 ```rust
 view! { cx,
-	<p>
-	{move || if is_odd() {
-		"Odd"
-	} else {
-		"Even"
-	}}
-	</p>
+    <p>
+    {move || if is_odd() {
+        "Odd"
+    } else {
+        "Even"
+    }}
+    </p>
 }
 ```
 
@@ -74,15 +74,15 @@ Let’s say we want to render some text if it’s odd, and nothing if it’s eve
 
 ```rust
 let message = move || {
-	if is_odd() {
-		Some("Ding ding ding!")
-	} else {
-		None
-	}
+    if is_odd() {
+        Some("Ding ding ding!")
+    } else {
+        None
+    }
 };
 
 view! { cx,
-	<p>{message}</p>
+    <p>{message}</p>
 }
 ```
 
@@ -91,7 +91,7 @@ This works fine. We can make it a little shorter if we’d like, using `bool::th
 ```rust
 let message = move || is_odd().then(|| "Ding ding ding!");
 view! { cx,
-	<p>{message}</p>
+    <p>{message}</p>
 }
 ```
 
@@ -105,15 +105,15 @@ pattern matching at your disposal.
 
 ```rust
 let message = move || {
-	match value() {
-		0 => "Zero",
-		1 => "One",
-		n if is_odd() => "Odd",
-		_ => "Even"
-	}
+    match value() {
+        0 => "Zero",
+        1 => "One",
+        n if is_odd() => "Odd",
+        _ => "Even"
+    }
 };
 view! { cx,
-	<p>{message}</p>
+    <p>{message}</p>
 }
 ```
 
@@ -134,13 +134,13 @@ But consider the following example:
 let (value, set_value) = create_signal(cx, 0);
 
 let message = move || if value() > 5 {
-	"Big"
+    "Big"
 } else {
-	"Small"
+    "Small"
 };
 
 view! { cx,
-	<p>{message}</p>
+    <p>{message}</p>
 }
 ```
 
@@ -148,11 +148,11 @@ This _works_, for sure. But if you added a log, you might be surprised
 
 ```rust
 let message = move || if value() > 5 {
-	log!("{}: rendering Big", value());
-	"Big"
+    log!("{}: rendering Big", value());
+    "Big"
 } else {
-	log!("{}: rendering Small", value());
-	"Small"
+    log!("{}: rendering Small", value());
+    "Small"
 };
 ```
 
@@ -177,9 +177,9 @@ like this:
 
 ```rust
 let message = move || if value() > 5 {
-	<Big/>
+    <Big/>
 } else {
-	<Small/>
+    <Small/>
 };
 ```
 
@@ -187,6 +187,8 @@ This rerenders `<Small/>` five times, then `<Big/>` infinitely. If they’re
 loading resources, creating signals, or even just creating DOM nodes, this is
 unnecessary work.
 
+### `<Show/>`
+
 The [`<Show/>`](https://docs.rs/leptos/latest/leptos/fn.Show.html) component is
 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`.
@@ -226,20 +228,20 @@ different branches of a conditional:
 
 ```rust,compile_error
 view! { cx,
-	<main>
-		{move || match is_odd() {
-			true if value() == 1 => {
-				// returns HtmlElement<Pre>
-				view! { cx, <pre>"One"</pre> }
-			},
-			false if value() == 2 => {
-				// returns HtmlElement<P>
-				view! { cx, <p>"Two"</p> }
-			}
-			// returns HtmlElement<Textarea>
-			_ => view! { cx, <textarea>{value()}</textarea> }
-		}}
-	</main>
+    <main>
+        {move || match is_odd() {
+            true if value() == 1 => {
+                // returns HtmlElement<Pre>
+                view! { cx, <pre>"One"</pre> }
+            },
+            false if value() == 2 => {
+                // returns HtmlElement<P>
+                view! { cx, <p>"Two"</p> }
+            }
+            // returns HtmlElement<Textarea>
+            _ => view! { cx, <textarea>{value()}</textarea> }
+        }}
+    </main>
 }
 ```
 
@@ -263,20 +265,20 @@ Here’s the same example, with the conversion added:
 
 ```rust,compile_error
 view! { cx,
-	<main>
-		{move || match is_odd() {
-			true if value() == 1 => {
-				// returns HtmlElement<Pre>
-				view! { cx, <pre>"One"</pre> }.into_any()
-			},
-			false if value() == 2 => {
-				// returns HtmlElement<P>
-				view! { cx, <p>"Two"</p> }.into_any()
-			}
-			// returns HtmlElement<Textarea>
-			_ => view! { cx, <textarea>{value()}</textarea> }.into_any()
-		}}
-	</main>
+    <main>
+        {move || match is_odd() {
+            true if value() == 1 => {
+                // returns HtmlElement<Pre>
+                view! { cx, <pre>"One"</pre> }.into_any()
+            },
+            false if value() == 2 => {
+                // returns HtmlElement<P>
+                view! { cx, <p>"Two"</p> }.into_any()
+            }
+            // returns HtmlElement<Textarea>
+            _ => view! { cx, <textarea>{value()}</textarea> }.into_any()
+        }}
+    </main>
 }
 ```
 

docs/book/src/view/07_errors.md

@@ -63,7 +63,7 @@ Let’s add an `<ErrorBoundary/>` to this example.
 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>());
+    let on_input = move |ev| set_value(event_target_value(&ev).parse::<i32>());
 
     view! { cx,
         <h1>"Error Handling"</h1>
@@ -77,9 +77,7 @@ let on_input = move |ev| set_value(event_target_value(&ev).parse::<i32>());
                         <p>"Not a number! Errors: "</p>
                         // we can render a list of errors as strings, if we'd like
                         <ul>
-                            {move || errors.unwrap()
-                                .get()
-                                .0
+                            {move || errors.get()
                                 .into_iter()
                                 .map(|(_, e)| view! { cx, <li>{e.to_string()}</li>})
                                 .collect::<Vec<_>>()

docs/book/src/view/08_parent_child.md

@@ -30,11 +30,11 @@ it in the child. This lets you manipulate the state of the parent from the child
 ```rust
 #[component]
 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/>
-	}
+    let (toggled, set_toggled) = create_signal(cx, false);
+    view! { cx,
+        <p>"Toggled? " {toggled}</p>
+        <ButtonA setter=set_toggled/>
+    }
 }
 
 #[component]
@@ -63,11 +63,11 @@ Another approach would be to pass a callback to the child: say, `on_click`.
 ```rust
 #[component]
 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)/>
-	}
+    let (toggled, set_toggled) = create_signal(cx, false);
+    view! { cx,
+        <p>"Toggled? " {toggled}</p>
+        <ButtonB on_click=move |_| set_toggled.update(|value| *value = !*value)/>
+    }
 }
 
 
@@ -106,13 +106,13 @@ in your `view` macro in `<App/>`.
 ```rust
 #[component]
 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
-		<ButtonC on:click=move |_| set_toggled.update(|value| *value = !*value)/>
-	}
+    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
+        <ButtonC on:click=move |_| set_toggled.update(|value| *value = !*value)/>
+    }
 }
 
 
@@ -142,31 +142,32 @@ tree:
 ```rust
 #[component]
 pub fn App(cx: Scope) -> impl IntoView {
-	let (toggled, set_toggled) = create_signal(cx, false);
-	view! { cx,
-		<p>"Toggled? " {toggled}</p>
-		<Layout/>
-	}
+    let (toggled, set_toggled) = create_signal(cx, false);
+    view! { cx,
+        <p>"Toggled? " {toggled}</p>
+        <Layout/>
+    }
 }
 
 #[component]
 pub fn Layout(cx: Scope) -> impl IntoView {
-	view! { cx,
-		<header>
-			<h1>"My Page"</h1>
-		<main>
-			<Content/>
-		</main>
-	}
+    view! { cx,
+        <header>
+            <h1>"My Page"</h1>
+        </header>
+        <main>
+            <Content/>
+        </main>
+    }
 }
 
 #[component]
 pub fn Content(cx: Scope) -> impl IntoView {
-	view! { cx,
-		<div class="content">
-			<ButtonD/>
-		</div>
-	}
+    view! { cx,
+        <div class="content">
+            <ButtonD/>
+        </div>
+    }
 }
 
 #[component]
@@ -182,31 +183,32 @@ pass your `WriteSignal` to its props. You could do what’s sometimes called
 ```rust
 #[component]
 pub fn App(cx: Scope) -> impl IntoView {
-	let (toggled, set_toggled) = create_signal(cx, false);
-	view! { cx,
-		<p>"Toggled? " {toggled}</p>
-		<Layout set_toggled/>
-	}
+    let (toggled, set_toggled) = create_signal(cx, false);
+    view! { cx,
+        <p>"Toggled? " {toggled}</p>
+        <Layout set_toggled/>
+    }
 }
 
 #[component]
 pub fn Layout(cx: Scope, set_toggled: WriteSignal<bool>) -> impl IntoView {
-	view! { cx,
-		<header>
-			<h1>"My Page"</h1>
-		<main>
-			<Content set_toggled/>
-		</main>
-	}
+    view! { cx,
+        <header>
+            <h1>"My Page"</h1>
+        </header>
+        <main>
+            <Content set_toggled/>
+        </main>
+    }
 }
 
 #[component]
 pub fn Content(cx: Scope, set_toggled: WriteSignal<bool>) -> impl IntoView {
-	view! { cx,
-		<div class="content">
-			<ButtonD set_toggled/>
-		</div>
-	}
+    view! { cx,
+        <div class="content">
+            <ButtonD set_toggled/>
+        </div>
+    }
 }
 
 #[component]
@@ -236,26 +238,26 @@ unnecessary prop drilling.
 ```rust
 #[component]
 pub fn App(cx: Scope) -> impl IntoView {
-	let (toggled, set_toggled) = create_signal(cx, false);
+    let (toggled, set_toggled) = create_signal(cx, false);
 
-	// share `set_toggled` with all children of this component
-	provide_context(cx, set_toggled);
+    // share `set_toggled` with all children of this component
+    provide_context(cx, set_toggled);
 
-	view! { cx,
-		<p>"Toggled? " {toggled}</p>
-		<Layout/>
-	}
+    view! { cx,
+        <p>"Toggled? " {toggled}</p>
+        <Layout/>
+    }
 }
 
 // <Layout/> and <Content/> omitted
 
 #[component]
 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>>(cx)
-		.expect("to have found the setter provided");
+    // 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>>(cx)
+        .expect("to have found the setter provided");
 
     view! { cx,
         <button

docs/book/src/view/09_component_children.md

@@ -0,0 +1,126 @@
+# Component Children
+
+It’s pretty common to want to pass children into a component, just as you can pass
+children into an HTML element. For example, imagine I have a `<FancyForm/>` component
+that enhances an HTML `<form>`. I need some way to pass all its inputs.
+
+```rust
+view! { cx,
+    <Form>
+        <fieldset>
+            <label>
+                "Some Input"
+                <input type="text" name="something"/>
+            </label>
+        </fieldset>
+        <button>"Submit"</button>
+    </Form>
+}
+```
+
+How can you do this in Leptos? There are basically two ways to pass components to
+other components:
+
+1. **render props**: properties that are functions that return a view
+2. the **`children`** prop: a special component property that includes anything
+   you pass as a child to the component.
+
+In fact, you’ve already seen these both in action in the [`<Show/>`](/view/06_control_flow.html#show) component:
+
+```rust
+view! { cx,
+  <Show
+    // `when` is a normal prop
+    when=move || value() > 5
+    // `fallback` is a "render prop": a function that returns a view
+    fallback=|cx| view! { cx, <Small/> }
+  >
+    // `<Big/>` (and anything else here)
+    // will be given to the `children` prop
+    <Big/>
+  </Show>
+}
+```
+
+Let’s 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,
+    /// `children` takes the `Children` type
+    children: Children,
+) -> impl IntoView
+where
+    F: Fn() -> IV,
+    IV: IntoView,
+{
+    view! { cx,
+        <h2>"Render Prop"</h2>
+        {render_prop()}
+
+        <h2>"Children"</h2>
+        {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(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.
+
+We can use the component like this:
+
+```rust
+view! { cx,
+    <TakesChildren render_prop=|| view! { cx, <p>"Hi, there!"</p> }>
+        // these get passed to `children`
+        "Some text"
+        <span>"A span"</span>
+    </TakesChildren>
+}
+```
+
+## Manipulating Children
+
+The [`Fragment`](https://docs.rs/leptos/latest/leptos/struct.Fragment.html) type is
+basically a way of wrapping a `Vec<View>`. You can insert it anywhere into your view.
+
+But you can also access those inner views directly to manipulate them. For example, here’s
+a component that takes its children and turns them into an unordered list.
+
+```rust
+#[component]
+pub fn WrapsChildren(cx: Scope, children: Children) -> impl IntoView {
+    // Fragment has `nodes` field that contains a Vec<View>
+    let children = children(cx)
+        .nodes
+        .into_iter()
+        .map(|child| view! { cx, <li>{child}</li> })
+        .collect::<Vec<_>>();
+
+    view! { cx,
+        <ul>{children}</ul>
+    }
+}
+```
+
+Calling it like this will create a list:
+
+```rust
+view! { cx,
+    <WrappedChildren>
+        "A"
+        "B"
+        "C"
+    </WrappedChildren>
+}
+```
+
+<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"></iframe>

examples/counter/Cargo.toml

@@ -10,5 +10,7 @@ log = "0.4"
 console_error_panic_hook = "0.1.7"
 
 [dev-dependencies]
+wasm-bindgen = "0.2"
 wasm-bindgen-test = "0.3.0"
+web-sys ="0.3"
 

examples/counter/tests/mod.rs

@@ -1,35 +1,105 @@
+use counter::*;
+use leptos::*;
+use wasm_bindgen::JsCast;
 use wasm_bindgen_test::*;
 
 wasm_bindgen_test_configure!(run_in_browser);
-use leptos::*;
-use web_sys::HtmlElement;
-use counter::*;
+
+#[wasm_bindgen_test]
+fn clear() {
+    let document = leptos::document();
+    let test_wrapper = document.create_element("section").unwrap();
+    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(),
+        |cx| view! { cx, <SimpleCounter initial_value=10 step=1/> },
+    );
+
+    // 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 let's click the `clear` button
+    clear.click();
+
+    // now let's test the <div> against the expected value
+    // we can do this by testing its `outerHTML`
+    assert_eq!(
+        div.outer_html(),
+        // here we spawn a mini reactive system, just to render the
+        // test case
+        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(cx, 0);
+
+            // we can remove the event listeners because they're not rendered to HTML
+            view! { cx,
+                <div>
+                    <button>"Clear"</button>
+                    <button>"-1"</button>
+                    <span>"Value: " {value} "!"</span>
+                    <button>"+1"</button>
+                </div>
+            }
+            // the view returned an HtmlElement<Div>, which is a smart pointer for
+            // a DOM element. So we can still just call .outer_html()
+            .outer_html()
+        })
+    );
+
+    // There's actually an easier way to do this...
+    // We can just test against a <SimpleCounter/> with the initial value 0
+    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()
+    });
+}
 
 #[wasm_bindgen_test]
 fn inc() {
-    mount_to_body(|cx| view! { cx, <SimpleCounter initial_value=0 step=1/> });
-
     let document = leptos::document();
-    let div = document.query_selector("div").unwrap().unwrap();
+    let test_wrapper = document.create_element("section").unwrap();
+    document.body().unwrap().append_child(&test_wrapper);
+
+    mount_to(
+        test_wrapper.clone().unchecked_into(),
+        |cx| view! { cx, <SimpleCounter initial_value=0 step=1/> },
+    );
+
+    // You can do testing with vanilla DOM operations
+    let document = leptos::document();
+    let div = test_wrapper.query_selector("div").unwrap().unwrap();
     let clear = div
         .first_child()
         .unwrap()
-        .dyn_into::<HtmlElement>()
+        .dyn_into::<web_sys::HtmlElement>()
         .unwrap();
     let dec = clear
         .next_sibling()
         .unwrap()
-        .dyn_into::<HtmlElement>()
+        .dyn_into::<web_sys::HtmlElement>()
         .unwrap();
     let text = dec
         .next_sibling()
         .unwrap()
-        .dyn_into::<HtmlElement>()
+        .dyn_into::<web_sys::HtmlElement>()
         .unwrap();
     let inc = text
         .next_sibling()
         .unwrap()
-        .dyn_into::<HtmlElement>()
+        .dyn_into::<web_sys::HtmlElement>()
         .unwrap();
 
     inc.click();
@@ -47,4 +117,40 @@ fn inc() {
     clear.click();
 
     assert_eq!(text.text_content(), Some("Value: 0!".to_string()));
+
+    // Or you can test against a sample view!
+    assert_eq!(
+        div.outer_html(),
+        run_scope(create_runtime(), |cx| {
+            let (value, _) = create_signal(cx, 0);
+            view! { cx,
+                <div>
+                    <button>"Clear"</button>
+                    <button>"-1"</button>
+                    <span>"Value: " {value} "!"</span>
+                    <button>"+1"</button>
+                </div>
+            }
+        }
+        .outer_html())
+    );
+
+    inc.click();
+
+    assert_eq!(
+        div.outer_html(),
+        run_scope(create_runtime(), |cx| {
+            // because we've clicked, it's as if the signal is starting at 1
+            let (value, _) = create_signal(cx, 1);
+            view! { cx,
+                <div>
+                    <button>"Clear"</button>
+                    <button>"-1"</button>
+                    <span>"Value: " {value} "!"</span>
+                    <button>"+1"</button>
+                </div>
+            }
+        }
+        .outer_html())
+    );
 }

examples/counter_isomorphic/Cargo.toml

@@ -12,7 +12,6 @@ actix-web = { version = "4", optional = true, features = ["macros"] }
 broadcaster = "1"
 console_log = "0.2"
 console_error_panic_hook = "0.1"
-serde = { version = "1", features = ["derive"] }
 futures = "0.3"
 cfg-if = "1"
 lazy_static = "1"
@@ -23,8 +22,9 @@ leptos_actix = { path = "../../integrations/actix", optional = true }
 leptos_meta = { path = "../../meta", default-features = false }
 leptos_router = { path = "../../router", default-features = false }
 log = "0.4"
-simple_logger = "4.0.0"
 gloo-net = { git = "https://github.com/rustwasm/gloo" }
+wasm-bindgen = "0.2"
+serde = { version = "1", features = ["derive"] }
 
 [features]
 default = []

examples/counter_isomorphic/src/counters.rs

@@ -97,10 +97,10 @@ pub fn Counter(cx: Scope) -> impl IntoView {
         |_| get_server_count(),
     );
 
-    let value = move || counter.read().map(|count| count.unwrap_or(0)).unwrap_or(0);
+    let value = move || counter.read(cx).map(|count| count.unwrap_or(0)).unwrap_or(0);
     let error_msg = move || {
         counter
-            .read()
+            .read(cx)
             .map(|res| match res {
                 Ok(_) => None,
                 Err(e) => Some(e),
@@ -143,7 +143,7 @@ pub fn FormCounter(cx: Scope) -> impl IntoView {
     let value = move || {
         log::debug!("FormCounter looking for value");
         counter
-            .read()
+            .read(cx)
             .map(|n| n.ok())
             .flatten()
             .map(|n| n)
@@ -194,16 +194,16 @@ pub fn MultiuserCounter(cx: Scope) -> impl IntoView {
         use futures::StreamExt;
 
         let mut source = gloo_net::eventsource::futures::EventSource::new("/api/events")
-            .expect_throw("couldn't connect to SSE stream");
+            .expect("couldn't connect to SSE stream");
         let s = create_signal_from_stream(
             cx,
             source.subscribe("message").unwrap().map(|value| {
                 value
-                    .expect_throw("no message event")
+                    .expect("no message event")
                     .1
                     .data()
                     .as_string()
-                    .expect_throw("expected string value")
+                    .expect("expected string value")
             }),
         );
 

examples/counter_isomorphic/src/lib.rs

@@ -10,7 +10,6 @@ cfg_if! {
 
         #[wasm_bindgen]
         pub fn hydrate() {
-            console_error_panic_hook::set_once();
             _ = console_log::init_with_level(log::Level::Debug);
             console_error_panic_hook::set_once();
 

examples/counter_without_macros/Makefile.toml

@@ -1,9 +1,9 @@
 [tasks.build]
 command = "cargo"
-args = ["+nightly", "build-all-features"]
+args = ["+stable", "build-all-features"]
 install_crate = "cargo-all-features"
 
 [tasks.check]
 command = "cargo"
-args = ["+nightly", "check-all-features"]
+args = ["+stable", "check-all-features"]
 install_crate = "cargo-all-features"

examples/counter_without_macros/src/lib.rs

@@ -1,4 +1,4 @@
-use leptos::{ev, *};
+use leptos::{ev, html::*, *};
 
 pub struct Props {
     /// The starting value for the counter
@@ -25,7 +25,9 @@ pub fn view(cx: Scope, props: Props) -> impl IntoView {
         .child((
             cx,
             button(cx)
-                .on(ev::click, move |_| set_value.update(|value| *value -= step))
+                .on(ev::click, move |_| {
+                    set_value.update(|value| *value -= step)
+                })
                 .child((cx, "-1")),
         ))
         .child((
@@ -38,7 +40,9 @@ pub fn view(cx: Scope, props: Props) -> impl IntoView {
         .child((
             cx,
             button(cx)
-                .on(ev::click, move |_| set_value.update(|value| *value += step))
+                .on(ev::click, move |_| {
+                    set_value.update(|value| *value += step)
+                })
                 .child((cx, "+1")),
         ))
 }

examples/counters/src/lib.rs

@@ -1,5 +1,4 @@
-use leptos::*;
-use leptos::{For, ForProps};
+use leptos::{For, ForProps, *};
 
 const MANY_COUNTERS: usize = 1000;
 
@@ -66,9 +65,8 @@ pub fn Counters(cx: Scope) -> impl IntoView {
                 <For
                     each=counters
                     key=|counter| counter.0
-                    view=move |(id, (value, set_value)): (usize, (ReadSignal<i32>, WriteSignal<i32>))| {
-                        view! {
-                            cx,
+                    view=move |cx, (id, (value, set_value)): (usize, (ReadSignal<i32>, WriteSignal<i32>))| {
+                        view! { cx,
                             <Counter id value set_value/>
                         }
                     }
@@ -85,9 +83,11 @@ fn Counter(
     value: ReadSignal<i32>,
     set_value: WriteSignal<i32>,
 ) -> impl IntoView {
-    let CounterUpdater { set_counters } = use_context(cx).unwrap_throw();
+    let CounterUpdater { set_counters } = use_context(cx).unwrap();
 
-    let input = move |ev| set_value(event_target_value(&ev).parse::<i32>().unwrap_or_default());
+    let input = move |ev| {
+        set_value(event_target_value(&ev).parse::<i32>().unwrap_or_default())
+    };
 
     // just an example of how a cleanup function works
     // this will run when the scope is disposed, i.e., when this row is deleted

examples/counters/src/main.rs

@@ -2,7 +2,6 @@ use counters::{Counters, CountersProps};
 use leptos::*;
 
 fn main() {
-    console_error_panic_hook::set_once();
     _ = console_log::init_with_level(log::Level::Debug);
     console_error_panic_hook::set_once();
     mount_to_body(|cx| view! { cx,  <Counters/> })

examples/counters_stable/src/main.rs

@@ -1,7 +1,6 @@
 use leptos::*;
 
 fn main() {
-    console_error_panic_hook::set_once();
     _ = console_log::init_with_level(log::Level::Debug);
     console_error_panic_hook::set_once();
     mount_to_body(|cx| view! { cx,  <Counters/> })
@@ -72,7 +71,7 @@ pub fn Counters(cx: Scope) -> impl IntoView {
                 <For
                     each={move || counters.get()}
                     key={|counter| counter.0}
-                    view=move |(id, (value, set_value))| {
+                    view=move |cx, (id, (value, set_value))| {
                         view! {
                             cx,
                             <Counter id value set_value/>
@@ -91,9 +90,12 @@ fn Counter(
     value: ReadSignal<i32>,
     set_value: WriteSignal<i32>,
 ) -> impl IntoView {
-    let CounterUpdater { set_counters } = use_context(cx).unwrap_throw();
+    let CounterUpdater { set_counters } = use_context(cx).unwrap();
 
-    let input = move |ev| set_value.set(event_target_value(&ev).parse::<i32>().unwrap_or_default());
+    let input = move |ev| {
+        set_value
+            .set(event_target_value(&ev).parse::<i32>().unwrap_or_default())
+    };
 
     view! { cx,
         <li>

examples/error_boundary/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "error_boundary"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+leptos = { path = "../../leptos" }
+console_log = "0.2"
+log = "0.4"
+console_error_panic_hook = "0.1.7"

examples/error_boundary/Makefile.toml

@@ -0,0 +1,9 @@
+[tasks.build]
+command = "cargo"
+args = ["+nightly", "build-all-features"]
+install_crate = "cargo-all-features"
+
+[tasks.check]
+command = "cargo"
+args = ["+nightly", "check-all-features"]
+install_crate = "cargo-all-features"

examples/error_boundary/README.md

@@ -0,0 +1,7 @@
+# Leptos `<ErrorBoundary/>` Example
+
+This example shows how to handle basic errors using Leptos.
+
+To run it, just issue the `trunk serve --open` command in the example root. This will build the app, run it, and open a new browser to serve it.
+
+> If you don't have `trunk` installed, [click here for install instructions.](https://trunkrs.dev/)

examples/error_boundary/index.html

@@ -0,0 +1,8 @@
+<!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"/>
+	</head>
+	<body></body>
+</html>

examples/error_boundary/src/lib.rs

@@ -0,0 +1,47 @@
+use leptos::*;
+
+#[component]
+pub fn App(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! { cx,
+        <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=|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! { cx, <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>
+    }
+}

examples/error_boundary/src/main.rs

@@ -0,0 +1,12 @@
+use error_boundary::*;
+use leptos::*;
+
+pub fn main() {
+    _ = console_log::init_with_level(log::Level::Debug);
+    console_error_panic_hook::set_once();
+    mount_to_body(|cx| {
+        view! { cx,
+            <App/>
+        }
+    })
+}

examples/errors_axum/Cargo.toml

@@ -7,70 +7,67 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-anyhow = "1.0.66"
 console_log = "0.2.0"
 console_error_panic_hook = "0.1.7"
-futures = "0.3.25"
 cfg-if = "1.0.0"
 leptos = { path = "../../../leptos/leptos", default-features = false, features = [
-	"serde",
+  "serde",
 ] }
 leptos_axum = { path = "../../../leptos/integrations/axum", default-features = false, optional = true }
 leptos_meta = { path = "../../../leptos/meta", default-features = false }
 leptos_router = { path = "../../../leptos/router", default-features = false }
-leptos_reactive = { path = "../../../leptos/leptos_reactive", default-features = false }
 log = "0.4.17"
+serde = { version = "1", features = ["derive"] }
 simple_logger = "4.0.0"
-serde = { version = "1.0.148", features = ["derive"] }
-serde_json = "1.0.89"
-gloo-net = { version = "0.2.5", features = ["http"] }
-reqwest = { version = "0.11.13", features = ["json"] }
 axum = { version = "0.6.1", optional = true }
 tower = { version = "0.4.13", optional = true }
-tower-http = { version = "0.3.4", features = ["fs"], optional = true }
+tower-http = { version = "0.4", features = ["fs"], optional = true }
 tokio = { version = "1.22.0", features = ["full"], optional = true }
 http = { version = "0.2.8" }
 thiserror = "1.0.38"
-tracing = "0.1.37"
+wasm-bindgen = "0.2"
 
 [features]
 default = ["csr"]
 csr = ["leptos/csr", "leptos_meta/csr", "leptos_router/csr"]
 hydrate = ["leptos/hydrate", "leptos_meta/hydrate", "leptos_router/hydrate"]
-ssr = ["dep:axum", "dep:tower", "dep:tower-http", "dep:tokio", "leptos/ssr", "leptos_meta/ssr", "leptos_router/ssr", "dep:leptos_axum"]
+ssr = [
+  "dep:axum",
+  "dep:tower",
+  "dep:tower-http",
+  "dep:tokio",
+  "leptos/ssr",
+  "leptos_meta/ssr",
+  "leptos_router/ssr",
+  "dep:leptos_axum",
+]
 
 [package.metadata.cargo-all-features]
-denylist = [
-	"axum",
-	"tower",
-	"tower-http",
-	"tokio",
-	"leptos_axum",
-]
+denylist = ["axum", "tower", "tower-http", "tokio", "leptos_axum"]
 skip_feature_sets = [["csr", "ssr"], ["csr", "hydrate"], ["ssr", "hydrate"]]
 
 [package.metadata.leptos]
-# The name used by wasm-bindgen/cargo-leptos for the JS/WASM bundle. Defaults to the crate name   
-output-name = "errors_axum"	
+# The name used by wasm-bindgen/cargo-leptos for the JS/WASM bundle. Defaults to the crate name
+output-name = "errors_axum"
 # The site root folder is where cargo-leptos generate all output. WARNING: all content of this folder will be erased on a rebuild. Use it in your server setup.
 site-root = "target/site"
 # The site-root relative folder where all compiled output (JS, WASM and CSS) is written
-# Defaults to pkg	
-site-pkg-dir = "pkg" 	
+# Defaults to pkg
+site-pkg-dir = "pkg"
 # [Optional] The source CSS file. If it ends with .sass or .scss then it will be compiled by dart-sass into CSS. The CSS is optimized by Lightning CSS before being written to <site-root>/<site-pkg>/app.css
 style-file = "./style.css"
 # [Optional] Files in the asset-dir will be copied to the site-root directory
 assets-dir = "public"
 # The IP and port (ex: 127.0.0.1:3000) where the server serves the content. Use it in your server setup.
-site-addr = "127.0.0.1:3000"	
+site-addr = "127.0.0.1:3000"
 # The port to use for automatic reload monitoring
-reload-port = 3001	
+reload-port = 3001
 # [Optional] Command to use when running end2end tests. It will run in the end2end dir.
 end2end-cmd = "npx playwright test"
 #  The browserlist query used for optimizing the CSS.
-browserquery = "defaults" 	
+browserquery = "defaults"
 # Set by cargo-leptos watch when building with tha tool. Controls whether autoreload JS will be included in the head
-watch = false 	
+watch = false
 # The environment Leptos will run in, usually either "DEV" or "PROD"
 env = "DEV"
 # The features to use when compiling the bin target

examples/errors_axum/src/error_template.rs

@@ -1,8 +1,6 @@
 use crate::errors::AppError;
 use cfg_if::cfg_if;
-use leptos::Errors;
-use leptos::*;
-
+use leptos::{Errors, *};
 #[cfg(feature = "ssr")]
 use leptos_axum::ResponseOptions;
 
@@ -23,12 +21,11 @@ pub fn ErrorTemplate(
     };
 
     // Get Errors from Signal
-    let errors = errors.get().0;
-
     // Downcast lets us take a type that implements `std::error::Error`
     let errors: Vec<AppError> = errors
+        .get()
         .into_iter()
-        .filter_map(|(_k, v)| v.downcast_ref::<AppError>().cloned())
+        .filter_map(|(_, v)| v.downcast_ref::<AppError>().cloned())
         .collect();
     log!("Errors: {errors:#?}");
 
@@ -47,9 +44,9 @@ pub fn ErrorTemplate(
             // a function that returns the items we're iterating over; a signal is fine
             each= move || {errors.clone().into_iter().enumerate()}
             // a unique key for each item as a reference
-            key=|(index, _error)| *index
+            key=|(index, _)| *index
             // renders each item to a view
-            view= move |error| {
+            view=move |cx, error| {
                 let error_string = error.1.to_string();
                 let error_code= error.1.status_code();
                 view! { cx,

examples/errors_axum/src/lib.rs

@@ -13,7 +13,6 @@ cfg_if! {
 
         #[wasm_bindgen]
         pub fn hydrate() {
-            console_error_panic_hook::set_once();
             _ = console_log::init_with_level(log::Level::Debug);
             console_error_panic_hook::set_once();
 

examples/fetch/index.html

@@ -9,6 +9,12 @@
 			max-width: 250px;
 			height: auto;
 		}
+
+		.error {
+			border: 1px solid red;
+			color: red;
+			background-color: lightpink;
+		}
 	</style>
 	<body></body>
 </html>

examples/fetch/src/lib.rs

@@ -1,3 +1,4 @@
+use anyhow::Result;
 use leptos::*;
 use serde::{Deserialize, Serialize};
 
@@ -6,18 +7,18 @@ pub struct Cat {
     url: String,
 }
 
-async fn fetch_cats(count: u32) -> Result<Vec<String>, ()> {
+async fn fetch_cats(count: u32) -> Result<Vec<String>> {
     if count > 0 {
+        // make the request
         let res = reqwasm::http::Request::get(&format!(
-            "https://api.thecatapi.com/v1/images/search?limit={}",
-            count
+            "https://api.thecatapi.com/v1/images/search?limit={count}",
         ))
         .send()
-        .await
-        .map_err(|_| ())?
+        .await?
+        // convert it to JSON
         .json::<Vec<Cat>>()
-        .await
-        .map_err(|_| ())?
+        .await?
+        // extract the URL field for each cat
         .into_iter()
         .map(|cat| cat.url)
         .collect::<Vec<_>>();
@@ -29,9 +30,45 @@ async fn fetch_cats(count: u32) -> Result<Vec<String>, ()> {
 
 pub fn fetch_example(cx: Scope) -> impl IntoView {
     let (cat_count, set_cat_count) = create_signal::<u32>(cx, 1);
-    let cats = create_resource(cx, cat_count, |count| fetch_cats(count));
 
-    view! { cx, 
+    // we use local_resource here because
+    // 1) anyhow::Result isn't serializable/deserializable
+    // 2) we're not doing server-side rendering in this example anyway
+    //    (during SSR, create_resource will begin loading on the server and resolve on the client)
+    let cats = create_local_resource(cx, cat_count, fetch_cats);
+
+    let fallback = move |cx, errors: RwSignal<Errors>| {
+        let error_list = move || {
+            errors.with(|errors| {
+                errors
+                    .iter()
+                    .map(|(_, e)| view! { cx, <li>{e.to_string()}</li>})
+                    .collect::<Vec<_>>()
+            })
+        };
+
+        view! { cx,
+            <div class="error">
+                <h2>"Error"</h2>
+                <ul>{error_list}</ul>
+            </div>
+        }
+    };
+
+    // the renderer can handle Option<_> and Result<_> states
+    // by displaying nothing for None if the resource is still loading
+    // and by using the ErrorBoundary fallback to catch Err(_)
+    // so we'll just implement our happy path and let the framework handle the rest
+    let cats_view = move || {
+        cats.with(cx, |data| {
+            data.iter()
+                .flatten()
+                .map(|cat| view! { cx, <img src={cat}/> })
+                .collect::<Vec<_>>()
+        })
+    };
+
+    view! { cx,
         <div>
             <label>
                 "How many cats would you like?"
@@ -43,25 +80,11 @@ pub fn fetch_example(cx: Scope) -> impl IntoView {
                     }
                 />
             </label>
-            <Transition fallback=move || view! { cx, <div>"Loading (Suspense Fallback)..."</div>}>
-                {move || {
-                        cats.read().map(|data| match data {
-                            Err(_) => view! { cx, <pre>"Error"</pre> }.into_view(cx),
-                            Ok(cats) => view! { cx, 
-                                <div>{
-                                    cats.iter()
-                                        .map(|src| {
-                                            view! { cx, 
-                                                <img src={src}/>
-                                            }
-                                        })
-                                        .collect::<Vec<_>>()
-                                }</div>
-                            }.into_view(cx),
-                        })
-                    }
-                }
-            </Transition>
+            <ErrorBoundary fallback>
+                <Transition fallback=move || view! { cx, <div>"Loading (Suspense Fallback)..."</div>}>
+                    {cats_view}
+                </Transition>
+            </ErrorBoundary>
         </div>
     }
 }

examples/fetch/src/main.rs

@@ -2,7 +2,6 @@ use fetch::fetch_example;
 use leptos::*;
 
 pub fn main() {
-    console_error_panic_hook::set_once();
     _ = console_log::init_with_level(log::Level::Debug);
     console_error_panic_hook::set_once();
     mount_to_body(fetch_example)

examples/hackernews/Cargo.toml

@@ -7,12 +7,10 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-anyhow = "1"
 actix-files = { version = "0.6", optional = true }
 actix-web = { version = "4", optional = true, features = ["macros"] }
 console_log = "0.2"
 console_error_panic_hook = "0.1"
-futures = "0.3"
 cfg-if = "1"
 leptos = { path = "../../leptos", default-features = false, features = [
 	"serde",
@@ -21,15 +19,13 @@ leptos_meta = { path = "../../meta", default-features = false }
 leptos_actix = { path = "../../integrations/actix", default-features = false, optional = true }
 leptos_router = { path = "../../router", default-features = false }
 log = "0.4"
-simple_logger = "4.0.0"
 serde = { version = "1", features = ["derive"] }
-serde_json = "1"
 gloo-net = { version = "0.2", features = ["http"] }
 reqwest = { version = "0.11", features = ["json"] }
+tracing = "0.1"
 # openssl = { version = "0.10", features = ["v110"] }
 wasm-bindgen = "0.2"
 web-sys = { version = "0.3", features = ["AbortController", "AbortSignal"] }
-tracing = "0.1"
 
 [features]
 csr = ["leptos/csr", "leptos_meta/csr", "leptos_router/csr"]

examples/hackernews/src/api.rs

@@ -34,7 +34,7 @@ where
             abort_controller.abort()
         }
     });
-    T::from_json(&json).ok()
+    T::de(&json).ok()
 }
 
 #[cfg(feature = "ssr")]
@@ -49,7 +49,7 @@ where
         .text()
         .await
         .ok()?;
-    T::from_json(&json).map_err(|e| log::error!("{e}")).ok()
+    T::de(&json).map_err(|e| log::error!("{e}")).ok()
 }
 
 #[derive(Debug, Deserialize, Serialize, PartialEq, Eq, Clone)]

examples/hackernews/src/routes/stories.rs

@@ -38,7 +38,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
     let (pending, set_pending) = create_signal(cx, false);
 
     let hide_more_link =
-        move || pending() || stories.read().unwrap_or(None).unwrap_or_default().len() < 28;
+        move || pending() || stories.read(cx).unwrap_or(None).unwrap_or_default().len() < 28;
 
     view! {
         cx,
@@ -82,7 +82,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
                         fallback=move || view! { cx,  <p>"Loading..."</p> }
                         set_pending=set_pending.into()
                     >
-                        {move || match stories.read() {
+                        {move || match stories.read(cx) {
                             None => None,
                             Some(None) => Some(view! { cx,  <p>"Error loading stories."</p> }.into_any()),
                             Some(Some(stories)) => {
@@ -91,7 +91,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
                                         <For
                                             each=move || stories.clone()
                                             key=|story| story.id
-                                            view=move |story: api::Story| {
+                                            view=move |cx, story: api::Story| {
                                                 view! { cx,
                                                     <Story story/>
                                                 }

examples/hackernews/src/routes/story.rs

@@ -17,13 +17,13 @@ pub fn Story(cx: Scope) -> impl IntoView {
             }
         },
     );
-    let meta_description = move || story.read().and_then(|story| story.map(|story| story.title)).unwrap_or_else(|| "Loading story...".to_string());
+    let meta_description = move || story.read(cx).and_then(|story| story.map(|story| story.title)).unwrap_or_else(|| "Loading story...".to_string());
 
     view! { cx,
         <>
             <Meta name="description" content=meta_description/>
                 <Suspense fallback=|| view! { cx, "Loading..." }>
-                    {move || story.read().map(|story| match story {
+                    {move || story.read(cx).map(|story| match story {
                         None => view! { cx,  <div class="item-view">"Error loading this story."</div> },
                         Some(story) => view! { cx,
                             <div class="item-view">
@@ -53,7 +53,7 @@ pub fn Story(cx: Scope) -> impl IntoView {
                                     <For
                                         each=move || story.comments.clone().unwrap_or_default()
                                         key=|comment| comment.id
-                                        view=move |comment| view! { cx,  <Comment comment /> }
+                                        view=move |cx, comment| view! { cx,  <Comment comment /> }
                                     />
                                 </ul>
                             </div>
@@ -98,7 +98,7 @@ pub fn Comment(cx: Scope, comment: api::Comment) -> impl IntoView {
                                 <For
                                     each=move || comments.clone()
                                     key=|comment| comment.id
-                                    view=move |comment: api::Comment| view! { cx, <Comment comment /> }
+                                    view=move |cx, comment: api::Comment| view! { cx, <Comment comment /> }
                                 />
                             </ul>
                         }

examples/hackernews/src/routes/users.rs

@@ -19,7 +19,7 @@ pub fn User(cx: Scope) -> impl IntoView {
     view! { cx,
         <div class="user-view">
             <Suspense fallback=|| view! { cx, "Loading..." }>
-                {move || user.read().map(|user| match user {
+                {move || user.read(cx).map(|user| match user {
                     None => view! { cx,  <h1>"User not found."</h1> }.into_any(),
                     Some(user) => view! { cx,
                         <div>

examples/hackernews_axum/Cargo.toml

@@ -7,13 +7,11 @@ edition = "2021"
 crate-type = ["cdylib", "rlib"]
 
 [dependencies]
-anyhow = "1.0.66"
 console_log = "0.2.0"
 console_error_panic_hook = "0.1.7"
-futures = "0.3.25"
 cfg-if = "1.0.0"
 leptos = { path = "../../leptos", default-features = false, features = [
-	"serde",
+  "serde",
 ] }
 leptos_axum = { path = "../../integrations/axum", optional = true }
 leptos_meta = { path = "../../meta", default-features = false }
@@ -21,32 +19,31 @@ leptos_router = { path = "../../router", default-features = false }
 log = "0.4.17"
 simple_logger = "4.0.0"
 serde = { version = "1.0.148", features = ["derive"] }
-serde_json = "1.0.89"
+tracing = "0.1"
 gloo-net = { version = "0.2.5", features = ["http"] }
 reqwest = { version = "0.11.13", features = ["json"] }
 axum = { version = "0.6.1", optional = true }
 tower = { version = "0.4.13", optional = true }
-tower-http = { version = "0.3.4", features = ["fs"], optional = true }
+tower-http = { version = "0.4", features = ["fs"], optional = true }
 tokio = { version = "1.22.0", features = ["full"], optional = true }
 http = { version = "0.2.8", optional = true }
 web-sys = { version = "0.3", features = ["AbortController", "AbortSignal"] }
 wasm-bindgen = "0.2"
-tracing = "0.1"
 
 [features]
 default = ["csr"]
 csr = ["leptos/csr", "leptos_meta/csr", "leptos_router/csr"]
 hydrate = ["leptos/hydrate", "leptos_meta/hydrate", "leptos_router/hydrate"]
 ssr = [
-	"dep:axum",
-	"dep:tower",
-	"dep:tower-http",
-	"dep:tokio",
-	"dep:http",
-	"leptos/ssr",
-	"leptos_axum",
-	"leptos_meta/ssr",
-	"leptos_router/ssr",
+  "dep:axum",
+  "dep:tower",
+  "dep:tower-http",
+  "dep:tokio",
+  "dep:http",
+  "leptos/ssr",
+  "leptos_axum",
+  "leptos_meta/ssr",
+  "leptos_router/ssr",
 ]
 
 [package.metadata.cargo-all-features]
@@ -54,27 +51,27 @@ denylist = ["axum", "tower", "tower-http", "tokio", "http", "leptos_axum"]
 skip_feature_sets = [["csr", "ssr"], ["csr", "hydrate"], ["ssr", "hydrate"]]
 
 [package.metadata.leptos]
-# The name used by wasm-bindgen/cargo-leptos for the JS/WASM bundle. Defaults to the crate name   
-output-name = "hackernews_axum"	
+# The name used by wasm-bindgen/cargo-leptos for the JS/WASM bundle. Defaults to the crate name
+output-name = "hackernews_axum"
 # The site root folder is where cargo-leptos generate all output. WARNING: all content of this folder will be erased on a rebuild. Use it in your server setup.
 site-root = "target/site"
 # The site-root relative folder where all compiled output (JS, WASM and CSS) is written
-# Defaults to pkg	
-site-pkg-dir = "pkg" 	
+# Defaults to pkg
+site-pkg-dir = "pkg"
 # [Optional] The source CSS file. If it ends with .sass or .scss then it will be compiled by dart-sass into CSS. The CSS is optimized by Lightning CSS before being written to <site-root>/<site-pkg>/app.css
 style-file = "./style.css"
 # [Optional] Files in the asset-dir will be copied to the site-root directory
 assets-dir = "public"
 # The IP and port (ex: 127.0.0.1:3000) where the server serves the content. Use it in your server setup.
-site-addr = "127.0.0.1:3000"	
+site-addr = "127.0.0.1:3000"
 # The port to use for automatic reload monitoring
-reload-port = 3001	
+reload-port = 3001
 # [Optional] Command to use when running end2end tests. It will run in the end2end dir.
 end2end-cmd = "npx playwright test"
 #  The browserlist query used for optimizing the CSS.
-browserquery = "defaults" 	
+browserquery = "defaults"
 # Set by cargo-leptos watch when building with tha tool. Controls whether autoreload JS will be included in the head
-watch = false 	
+watch = false
 # The environment Leptos will run in, usually either "DEV" or "PROD"
 env = "DEV"
 # The features to use when compiling the bin target
@@ -95,4 +92,4 @@ lib-features = ["hydrate"]
 # If the --no-default-features flag should be used when compiling the lib target
 #
 # Optional. Defaults to false.
-lib-default-features = false
+lib-default-features = false

examples/hackernews_axum/index.html

@@ -2,7 +2,7 @@
 <html>
 	<head>
 		<link data-trunk rel="rust" data-wasm-opt="z"/>
-		<link data-trunk rel="css" href="./static/style.css"/>
+		<link data-trunk rel="css" href="/style.css"/>
 	</head>
 	<body></body>
 </html>

examples/hackernews_axum/src/api.rs

@@ -34,7 +34,7 @@ where
             abort_controller.abort()
         }
     });
-    T::from_json(&json).ok()
+    T::de(&json).ok()
 }
 
 #[cfg(feature = "ssr")]
@@ -49,7 +49,7 @@ where
         .text()
         .await
         .ok()?;
-    T::from_json(&json).map_err(|e| log::error!("{e}")).ok()
+    T::de(&json).map_err(|e| log::error!("{e}")).ok()
 }
 
 #[derive(Debug, Deserialize, Serialize, PartialEq, Eq, Clone)]

examples/hackernews_axum/src/error_template.rs

@@ -1,5 +1,7 @@
-use leptos::Errors;
-use leptos::{view, For, ForProps, IntoView, RwSignal, Scope, View};
+use leptos::{
+    signal_prelude::*, view, Errors, For, ForProps, IntoView, RwSignal, Scope,
+    View,
+};
 
 // A basic function to display errors served by the error boundaries. Feel free to do more complicated things
 // here than just displaying them
@@ -7,21 +9,22 @@ pub fn error_template(cx: Scope, errors: Option<RwSignal<Errors>>) -> View {
     let Some(errors) = errors else {
         panic!("No Errors found and we expected errors!");
     };
+
     view! {cx,
-    <h1>"Errors"</h1>
-    <For
-        // a function that returns the items we're iterating over; a signal is fine
-        each= move || {errors.get().0.into_iter()}
-        // a unique key for each item as a reference
-        key=|error| error.0.clone()
-        // renders each item to a view
-        view= move |error| {
-        let error_string = error.1.to_string();
-          view! {
-            cx,
-            <p>"Error: " {error_string}</p>
+      <h1>"Errors"</h1>
+      <For
+          // a function that returns the items we're iterating over; a signal is fine
+          each=errors
+          // a unique key for each item as a reference
+          key=|(key, _)| key.clone()
+          // renders each item to a view
+          view= move |cx, (_, error)| {
+          let error_string = error.to_string();
+            view! {
+              cx,
+              <p>"Error: " {error_string}</p>
+            }
           }
-        }
       />
     }
     .into_view(cx)

examples/hackernews_axum/src/main.rs

@@ -46,7 +46,6 @@ if #[cfg(feature = "ssr")] {
         use hackernews_axum::*;
 
         pub fn main() {
-            console_error_panic_hook::set_once();
             _ = console_log::init_with_level(log::Level::Debug);
             console_error_panic_hook::set_once();
             mount_to_body(|cx| {

examples/hackernews_axum/src/routes/stories.rs

@@ -38,7 +38,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
     let (pending, set_pending) = create_signal(cx, false);
 
     let hide_more_link =
-        move || pending() || stories.read().unwrap_or(None).unwrap_or_default().len() < 28;
+        move || pending() || stories.read(cx).unwrap_or(None).unwrap_or_default().len() < 28;
 
     view! {
         cx,
@@ -82,7 +82,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
                         fallback=move || view! { cx,  <p>"Loading..."</p> }
                         set_pending=set_pending.into()
                     >
-                        {move || match stories.read() {
+                        {move || match stories.read(cx) {
                             None => None,
                             Some(None) => Some(view! { cx,  <p>"Error loading stories."</p> }.into_any()),
                             Some(Some(stories)) => {
@@ -91,7 +91,7 @@ pub fn Stories(cx: Scope) -> impl IntoView {
                                         <For
                                             each=move || stories.clone()
                                             key=|story| story.id
-                                            view=move |story: api::Story| {
+                                            view=move |cx, story: api::Story| {
                                                 view! { cx,
                                                     <Story story/>
                                                 }

examples/hackernews_axum/src/routes/story.rs

@@ -17,13 +17,13 @@ pub fn Story(cx: Scope) -> impl IntoView {
             }
         },
     );
-    let meta_description = move || story.read().and_then(|story| story.map(|story| story.title)).unwrap_or_else(|| "Loading story...".to_string());
+    let meta_description = move || story.read(cx).and_then(|story| story.map(|story| story.title)).unwrap_or_else(|| "Loading story...".to_string());
 
     view! { cx,
         <>
             <Meta name="description" content=meta_description/>
                 <Suspense fallback=|| view! { cx, "Loading..." }>
-                    {move || story.read().map(|story| match story {
+                    {move || story.read(cx).map(|story| match story {
                         None => view! { cx,  <div class="item-view">"Error loading this story."</div> },
                         Some(story) => view! { cx,
                             <div class="item-view">
@@ -53,7 +53,7 @@ pub fn Story(cx: Scope) -> impl IntoView {
                                     <For
                                         each=move || story.comments.clone().unwrap_or_default()
                                         key=|comment| comment.id
-                                        view=move |comment| view! { cx,  <Comment comment /> }
+                                        view=move |cx, comment| view! { cx,  <Comment comment /> }
                                     />
                                 </ul>
                             </div>
@@ -98,7 +98,7 @@ pub fn Comment(cx: Scope, comment: api::Comment) -> impl IntoView {
                                 <For
                                     each=move || comments.clone()
                                     key=|comment| comment.id
-                                    view=move |comment: api::Comment| view! { cx, <Comment comment /> }
+                                    view=move |cx, comment: api::Comment| view! { cx, <Comment comment /> }
                                 />
                             </ul>
                         }

examples/hackernews_axum/src/routes/users.rs

@@ -19,7 +19,7 @@ pub fn User(cx: Scope) -> impl IntoView {
     view! { cx,
         <div class="user-view">
             <Suspense fallback=|| view! { cx, "Loading..." }>
-                {move || user.read().map(|user| match user {
+                {move || user.read(cx).map(|user| match user {
                     None => view! { cx,  <h1>"User not found."</h1> }.into_any(),
                     Some(user) => view! { cx,
                         <div>

examples/login_with_token_csr_only/Cargo.toml

@@ -0,0 +1,7 @@
+[workspace]
+members = ["client", "api-boundary", "server"]
+
+[patch.crates-io]
+leptos = { path = "../../leptos" }
+leptos_router = { path = "../../router" }
+api-boundary = { path = "api-boundary" }

examples/login_with_token_csr_only/Makefile.toml

@@ -0,0 +1,9 @@
+[tasks.build]
+command = "cargo"
+args = ["+nightly", "build-all-features"]
+install_crate = "cargo-all-features"
+
+[tasks.check]
+command = "cargo"
+args = ["+nightly", "check-all-features"]
+install_crate = "cargo-all-features"

examples/login_with_token_csr_only/README.md

@@ -0,0 +1,23 @@
+# Leptos Login Example
+
+This example demonstrates a scenario of a client-side rendered application
+that uses an existing API that you cannot or do not want to change.
+The authentications of this example are done using an API token.
+
+## Run
+
+First start the example server:
+
+```
+cd server/ && cargo run
+```
+
+then use [`trunk`](https://trunkrs.dev) to serve the SPA:
+
+```
+cd client/ && trunk serve
+```
+
+finally you can visit the web application at `http://localhost:8080`
+
+The `api-boundary` crate contains data structures that are used by the server and the client.

examples/login_with_token_csr_only/api-boundary/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "api-boundary"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+serde = { version = "1.0", features = ["derive"] }

examples/login_with_token_csr_only/api-boundary/src/lib.rs

@@ -0,0 +1,22 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize)]
+pub struct Credentials {
+    pub email: String,
+    pub password: String,
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct UserInfo {
+    pub email: String,
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct ApiToken {
+    pub token: String,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Error {
+    pub message: String,
+}

examples/login_with_token_csr_only/client/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "client"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+api-boundary = "*"
+
+leptos = { version = "0.2.0-alpha2", features = ["stable"] }
+leptos_router = { version = "0.2.0-alpha2", features = ["stable", "csr"] }
+
+log = "0.4"
+console_error_panic_hook = "0.1"
+console_log = "0.2"
+gloo-net = "0.2"
+gloo-storage = "0.2"
+serde = "1.0"
+thiserror = "1.0"

examples/login_with_token_csr_only/client/Trunk.toml

@@ -0,0 +1,3 @@
+[[proxy]]
+rewrite = "/api/"
+backend = "http://0.0.0.0:3000/"

examples/login_with_token_csr_only/client/index.html

@@ -0,0 +1,7 @@
+<!DOCTYPE html>
+<html>
+	<head>
+		<link data-trunk rel="rust" data-wasm-opt="z" data-weak-refs/>
+	</head>
+	<body></body>
+</html>

examples/login_with_token_csr_only/client/src/api.rs

@@ -0,0 +1,94 @@
+use gloo_net::http::{Request, Response};
+use serde::de::DeserializeOwned;
+use thiserror::Error;
+
+use api_boundary::*;
+
+#[derive(Clone, Copy)]
+pub struct UnauthorizedApi {
+    url: &'static str,
+}
+
+#[derive(Clone)]
+pub struct AuthorizedApi {
+    url: &'static str,
+    token: ApiToken,
+}
+
+impl UnauthorizedApi {
+    pub const fn new(url: &'static str) -> Self {
+        Self { url }
+    }
+    pub async fn register(&self, credentials: &Credentials) -> Result<()> {
+        let url = format!("{}/users", self.url);
+        let response = Request::post(&url).json(credentials)?.send().await?;
+        into_json(response).await
+    }
+    pub async fn login(
+        &self,
+        credentials: &Credentials,
+    ) -> Result<AuthorizedApi> {
+        let url = format!("{}/login", self.url);
+        let response = Request::post(&url).json(credentials)?.send().await?;
+        let token = into_json(response).await?;
+        Ok(AuthorizedApi::new(self.url, token))
+    }
+}
+
+impl AuthorizedApi {
+    pub const fn new(url: &'static str, token: ApiToken) -> Self {
+        Self { url, token }
+    }
+    fn auth_header_value(&self) -> String {
+        format!("Bearer {}", self.token.token)
+    }
+    async fn send<T>(&self, req: Request) -> Result<T>
+    where
+        T: DeserializeOwned,
+    {
+        let response = req
+            .header("Authorization", &self.auth_header_value())
+            .send()
+            .await?;
+        into_json(response).await
+    }
+    pub async fn logout(&self) -> Result<()> {
+        let url = format!("{}/logout", self.url);
+        self.send(Request::post(&url)).await
+    }
+    pub async fn user_info(&self) -> Result<UserInfo> {
+        let url = format!("{}/users", self.url);
+        self.send(Request::get(&url)).await
+    }
+    pub fn token(&self) -> &ApiToken {
+        &self.token
+    }
+}
+
+type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error(transparent)]
+    Fetch(#[from] gloo_net::Error),
+    #[error("{0:?}")]
+    Api(api_boundary::Error),
+}
+
+impl From<api_boundary::Error> for Error {
+    fn from(e: api_boundary::Error) -> Self {
+        Self::Api(e)
+    }
+}
+
+async fn into_json<T>(response: Response) -> Result<T>
+where
+    T: DeserializeOwned,
+{
+    // ensure we've got 2xx status
+    if response.ok() {
+        Ok(response.json().await?)
+    } else {
+        Err(response.json::<api_boundary::Error>().await?.into())
+    }
+}

examples/login_with_token_csr_only/client/src/components/credentials.rs

@@ -0,0 +1,73 @@
+use leptos::{ev, *};
+
+#[component]
+pub fn CredentialsForm(
+    cx: Scope,
+    title: &'static str,
+    action_label: &'static str,
+    action: Action<(String, String), ()>,
+    error: Signal<Option<String>>,
+    disabled: Signal<bool>,
+) -> impl IntoView {
+    let (password, set_password) = create_signal(cx, String::new());
+    let (email, set_email) = create_signal(cx, String::new());
+
+    let dispatch_action =
+        move || action.dispatch((email.get(), password.get()));
+
+    let button_is_disabled = Signal::derive(cx, move || {
+        disabled.get() || password.get().is_empty() || email.get().is_empty()
+    });
+
+    view! { cx,
+      <form on:submit=|ev|ev.prevent_default()>
+        <p>{ title }</p>
+        {move || error.get().map(|err| view!{ cx,
+          <p style ="color:red;" >{ err }</p>
+        })}
+        <input
+          type = "email"
+          required
+          placeholder = "Email address"
+          prop:disabled = move || disabled.get()
+          on:keyup = move |ev: ev::KeyboardEvent| {
+            let val = event_target_value(&ev);
+            set_email.update(|v|*v = val);
+          }
+          // The `change` event fires when the browser fills the form automatically,
+          on:change = move |ev| {
+            let val = event_target_value(&ev);
+            set_email.update(|v|*v = val);
+          }
+        />
+        <input
+          type = "password"
+          required
+          placeholder = "Password"
+          prop:disabled = move || disabled.get()
+          on:keyup = move |ev: ev::KeyboardEvent| {
+            match &*ev.key() {
+                "Enter" => {
+                   dispatch_action();
+                }
+                _=> {
+                   let val = event_target_value(&ev);
+                   set_password.update(|p|*p = val);
+                }
+            }
+          }
+          // The `change` event fires when the browser fills the form automatically,
+          on:change = move |ev| {
+            let val = event_target_value(&ev);
+            set_password.update(|p|*p = val);
+          }
+        />
+        <button
+          prop:disabled = move || button_is_disabled.get()
+          on:click = move |_| dispatch_action()
+        >
+        { action_label }
+        </button>
+      </form>
+    }
+}

examples/login_with_token_csr_only/client/src/components/mod.rs

@@ -0,0 +1,4 @@
+pub mod credentials;
+pub mod navbar;
+
+pub use self::{credentials::*, navbar::*};

examples/login_with_token_csr_only/client/src/components/navbar.rs

@@ -0,0 +1,32 @@
+use leptos::*;
+use leptos_router::*;
+
+use crate::Page;
+
+#[component]
+pub fn NavBar<F>(
+    cx: Scope,
+    logged_in: Signal<bool>,
+    on_logout: F,
+) -> impl IntoView
+where
+    F: Fn() + 'static + Clone,
+{
+    view! { cx,
+      <nav>
+        <Show
+          when = move || logged_in.get()
+          fallback = |cx| view! { cx,
+            <A href=Page::Login.path() >"Login"</A>
+            " | "
+            <A href=Page::Register.path() >"Register"</A>
+          }
+        >
+          <a href="#" on:click={
+            let on_logout = on_logout.clone();
+            move |_| on_logout()
+          }>"Logout"</a>
+        </Show>
+      </nav>
+    }
+}

examples/login_with_token_csr_only/client/src/lib.rs

@@ -0,0 +1,130 @@
+use gloo_storage::{LocalStorage, Storage};
+use leptos::*;
+use leptos_router::*;
+
+use api_boundary::*;
+
+mod api;
+mod components;
+mod pages;
+
+use self::{components::*, pages::*};
+
+const DEFAULT_API_URL: &str = "/api";
+const API_TOKEN_STORAGE_KEY: &str = "api-token";
+
+#[component]
+pub fn App(cx: Scope) -> impl IntoView {
+    // -- signals -- //
+
+    let authorized_api = create_rw_signal(cx, None::<api::AuthorizedApi>);
+    let user_info = create_rw_signal(cx, None::<UserInfo>);
+    let logged_in = Signal::derive(cx, move || authorized_api.get().is_some());
+
+    // -- actions -- //
+
+    let fetch_user_info = create_action(cx, move |_| async move {
+        match authorized_api.get() {
+            Some(api) => match api.user_info().await {
+                Ok(info) => {
+                    user_info.update(|i| *i = Some(info));
+                }
+                Err(err) => {
+                    log::error!("Unable to fetch user info: {err}")
+                }
+            },
+            None => {
+                log::error!("Unable to fetch user info: not logged in")
+            }
+        }
+    });
+
+    let logout = create_action(cx, move |_| async move {
+        match authorized_api.get() {
+            Some(api) => match api.logout().await {
+                Ok(_) => {
+                    authorized_api.update(|a| *a = None);
+                    user_info.update(|i| *i = None);
+                }
+                Err(err) => {
+                    log::error!("Unable to logout: {err}")
+                }
+            },
+            None => {
+                log::error!("Unable to logout user: not logged in")
+            }
+        }
+    });
+
+    // -- callbacks -- //
+
+    let on_logout = move || {
+        logout.dispatch(());
+    };
+
+    // -- init API -- //
+
+    let unauthorized_api = api::UnauthorizedApi::new(DEFAULT_API_URL);
+    if let Ok(token) = LocalStorage::get(API_TOKEN_STORAGE_KEY) {
+        let api = api::AuthorizedApi::new(DEFAULT_API_URL, token);
+        authorized_api.update(|a| *a = Some(api));
+        fetch_user_info.dispatch(());
+    }
+
+    log::debug!("User is logged in: {}", logged_in.get());
+
+    // -- effects -- //
+
+    create_effect(cx, move |_| {
+        log::debug!("API authorization state changed");
+        match authorized_api.get() {
+            Some(api) => {
+                log::debug!(
+                    "API is now authorized: save token in LocalStorage"
+                );
+                LocalStorage::set(API_TOKEN_STORAGE_KEY, api.token())
+                    .expect("LocalStorage::set");
+            }
+            None => {
+                log::debug!("API is no longer authorized: delete token from LocalStorage");
+                LocalStorage::delete(API_TOKEN_STORAGE_KEY);
+            }
+        }
+    });
+
+    view! { cx,
+      <Router>
+        <NavBar logged_in on_logout />
+        <main>
+          <Routes>
+            <Route
+              path=Page::Home.path()
+              view=move |cx| view! { cx,
+                <Home user_info = user_info.into() />
+              }
+            />
+            <Route
+              path=Page::Login.path()
+              view=move |cx| view! { cx,
+                <Login
+                  api = unauthorized_api
+                  on_success = move |api| {
+                      log::info!("Successfully logged in");
+                      authorized_api.update(|v| *v = Some(api));
+                      let navigate = use_navigate(cx);
+                      navigate(Page::Home.path(), Default::default()).expect("Home route");
+                      fetch_user_info.dispatch(());
+                  } />
+              }
+            />
+            <Route
+              path=Page::Register.path()
+              view=move |cx| view! { cx,
+                <Register api = unauthorized_api />
+              }
+            />
+          </Routes>
+        </main>
+      </Router>
+    }
+}

examples/login_with_token_csr_only/client/src/main.rs

@@ -0,0 +1,9 @@
+use leptos::*;
+
+use client::*;
+
+pub fn main() {
+    _ = console_log::init_with_level(log::Level::Debug);
+    console_error_panic_hook::set_once();
+    mount_to_body(|cx| view! { cx, <App /> })
+}

examples/login_with_token_csr_only/client/src/pages/home.rs

@@ -0,0 +1,20 @@
+use crate::Page;
+use api_boundary::UserInfo;
+use leptos::*;
+use leptos_router::*;
+
+#[component]
+pub fn Home(cx: Scope, user_info: Signal<Option<UserInfo>>) -> impl IntoView {
+    view! { cx,
+      <h2>"Leptos Login example"</h2>
+      {move || match user_info.get() {
+        Some(info) => view!{ cx,
+          <p>"You are logged in with "{ info.email }"."</p>
+        }.into_view(cx),
+        None => view!{ cx,
+          <p>"You are not logged in."</p>
+          <A href=Page::Login.path() >"Login now."</A>
+        }.into_view(cx)
+      }}
+    }
+}

examples/login_with_token_csr_only/client/src/pages/login.rs

@@ -0,0 +1,66 @@
+use leptos::*;
+use leptos_router::*;
+
+use api_boundary::*;
+
+use crate::{
+    api::{self, AuthorizedApi, UnauthorizedApi},
+    components::credentials::*,
+    Page,
+};
+
+#[component]
+pub fn Login<F>(cx: Scope, api: UnauthorizedApi, on_success: F) -> impl IntoView
+where
+    F: Fn(AuthorizedApi) + 'static + Clone,
+{
+    let (login_error, set_login_error) = create_signal(cx, None::<String>);
+    let (wait_for_response, set_wait_for_response) = create_signal(cx, false);
+
+    let login_action =
+        create_action(cx, move |(email, password): &(String, String)| {
+            log::debug!("Try to login with {email}");
+            let email = email.to_string();
+            let password = password.to_string();
+            let credentials = Credentials { email, password };
+            let on_success = on_success.clone();
+            async move {
+                set_wait_for_response.update(|w| *w = true);
+                let result = api.login(&credentials).await;
+                set_wait_for_response.update(|w| *w = false);
+                match result {
+                    Ok(res) => {
+                        set_login_error.update(|e| *e = None);
+                        on_success(res);
+                    }
+                    Err(err) => {
+                        let msg = match err {
+                            api::Error::Fetch(js_err) => {
+                                format!("{js_err:?}")
+                            }
+                            api::Error::Api(err) => err.message,
+                        };
+                        error!(
+                            "Unable to login with {}: {msg}",
+                            credentials.email
+                        );
+                        set_login_error.update(|e| *e = Some(msg));
+                    }
+                }
+            }
+        });
+
+    let disabled = Signal::derive(cx, move || wait_for_response.get());
+
+    view! { cx,
+      <CredentialsForm
+        title = "Please login to your account"
+        action_label = "Login"
+        action = login_action
+        error = login_error.into()
+        disabled
+      />
+      <p>"Don't have an account?"</p>
+      <A href=Page::Register.path()>"Register"</A>
+    }
+}

examples/login_with_token_csr_only/client/src/pages/mod.rs

@@ -0,0 +1,23 @@
+pub mod home;
+pub mod login;
+pub mod register;
+
+pub use self::{home::*, login::*, register::*};
+
+#[derive(Debug, Clone, Copy, Default)]
+pub enum Page {
+    #[default]
+    Home,
+    Login,
+    Register,
+}
+
+impl Page {
+    pub fn path(&self) -> &'static str {
+        match self {
+            Self::Home => "/",
+            Self::Login => "/login",
+            Self::Register => "/register",
+        }
+    }
+}

examples/login_with_token_csr_only/client/src/pages/register.rs

@@ -0,0 +1,77 @@
+use leptos::*;
+use leptos_router::*;
+
+use api_boundary::*;
+
+use crate::{
+    api::{self, UnauthorizedApi},
+    components::credentials::*,
+    Page,
+};
+
+#[component]
+pub fn Register(cx: Scope, api: UnauthorizedApi) -> impl IntoView {
+    let (register_response, set_register_response) =
+        create_signal(cx, None::<()>);
+    let (register_error, set_register_error) =
+        create_signal(cx, None::<String>);
+    let (wait_for_response, set_wait_for_response) = create_signal(cx, false);
+
+    let register_action =
+        create_action(cx, move |(email, password): &(String, String)| {
+            let email = email.to_string();
+            let password = password.to_string();
+            let credentials = Credentials { email, password };
+            log!("Try to register new account for {}", credentials.email);
+            async move {
+                set_wait_for_response.update(|w| *w = true);
+                let result = api.register(&credentials).await;
+                set_wait_for_response.update(|w| *w = false);
+                match result {
+                    Ok(res) => {
+                        set_register_response.update(|v| *v = Some(res));
+                        set_register_error.update(|e| *e = None);
+                    }
+                    Err(err) => {
+                        let msg = match err {
+                            api::Error::Fetch(js_err) => {
+                                format!("{js_err:?}")
+                            }
+                            api::Error::Api(err) => err.message,
+                        };
+                        log::warn!(
+                            "Unable to register new account for {}: {msg}",
+                            credentials.email
+                        );
+                        set_register_error.update(|e| *e = Some(msg));
+                    }
+                }
+            }
+        });
+
+    let disabled = Signal::derive(cx, move || wait_for_response.get());
+
+    view! { cx,
+      <Show
+        when = move || register_response.get().is_some()
+        fallback = move |_| view!{ cx,
+          <CredentialsForm
+            title = "Please enter the desired credentials"
+            action_label = "Register"
+            action = register_action
+            error = register_error.into()
+            disabled
+          />
+          <p>"Your already have an account?"</p>
+          <A href=Page::Login.path()>"Login"</A>
+        }
+      >
+        <p>"You have successfully registered."</p>
+        <p>
+         "You can now "
+         <A href=Page::Login.path()>"login"</A>
+         " with your new account."
+        </p>
+      </Show>
+    }
+}

examples/login_with_token_csr_only/server/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "server"
+version = "0.0.0"
+edition = "2021"
+publish = false
+
+[dependencies]
+anyhow = "1.0"
+api-boundary = "*"
+axum = { version = "0.6", features = ["headers"] }
+env_logger = "0.10"
+log = "0.4"
+mailparse = "0.14"
+pwhash = "1.0"
+thiserror = "1.0"
+tokio = { version = "1.25", features = ["macros", "rt-multi-thread"] }
+tower-http = { version = "0.4", features = ["cors"] }
+uuid = { version = "1.3", features = ["v4"] }

examples/login_with_token_csr_only/server/src/adapters.rs

@@ -0,0 +1,114 @@
+use crate::{application::*, Error};
+use api_boundary as json;
+use axum::{
+    http::StatusCode,
+    response::Json,
+    response::{IntoResponse, Response},
+};
+use thiserror::Error;
+
+impl From<InvalidEmailAddress> for json::Error {
+    fn from(_: InvalidEmailAddress) -> Self {
+        Self {
+            message: "Invalid email address".to_string(),
+        }
+    }
+}
+
+impl From<InvalidPassword> for json::Error {
+    fn from(err: InvalidPassword) -> Self {
+        let InvalidPassword::TooShort(min_len) = err;
+        Self {
+            message: format!("Invalid password (min. length = {min_len})"),
+        }
+    }
+}
+
+impl From<CreateUserError> for json::Error {
+    fn from(err: CreateUserError) -> Self {
+        let message = match err {
+            CreateUserError::UserExists => "User already exits".to_string(),
+        };
+        Self { message }
+    }
+}
+
+impl From<LoginError> for json::Error {
+    fn from(err: LoginError) -> Self {
+        let message = match err {
+            LoginError::InvalidEmailOrPassword => {
+                "Invalid email or password".to_string()
+            }
+        };
+        Self { message }
+    }
+}
+
+impl From<LogoutError> for json::Error {
+    fn from(err: LogoutError) -> Self {
+        let message = match err {
+            LogoutError::NotLoggedIn => "No user is logged in".to_string(),
+        };
+        Self { message }
+    }
+}
+
+impl From<AuthError> for json::Error {
+    fn from(err: AuthError) -> Self {
+        let message = match err {
+            AuthError::NotAuthorized => "Not authorized".to_string(),
+        };
+        Self { message }
+    }
+}
+
+impl From<CredentialParsingError> for json::Error {
+    fn from(err: CredentialParsingError) -> Self {
+        match err {
+            CredentialParsingError::EmailAddress(err) => err.into(),
+            CredentialParsingError::Password(err) => err.into(),
+        }
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum CredentialParsingError {
+    #[error(transparent)]
+    EmailAddress(#[from] InvalidEmailAddress),
+    #[error(transparent)]
+    Password(#[from] InvalidPassword),
+}
+
+impl TryFrom<json::Credentials> for Credentials {
+    type Error = CredentialParsingError;
+    fn try_from(
+        json::Credentials { email, password }: json::Credentials,
+    ) -> Result<Self, Self::Error> {
+        let email: EmailAddress = email.parse()?;
+        let password = Password::try_from(password)?;
+        Ok(Self { email, password })
+    }
+}
+
+impl IntoResponse for Error {
+    fn into_response(self) -> Response {
+        let (code, value) = match self {
+            Self::Logout(err) => {
+                (StatusCode::BAD_REQUEST, json::Error::from(err))
+            }
+            Self::Login(err) => {
+                (StatusCode::BAD_REQUEST, json::Error::from(err))
+            }
+            Self::Credentials(err) => {
+                (StatusCode::BAD_REQUEST, json::Error::from(err))
+            }
+            Self::CreateUser(err) => {
+                (StatusCode::BAD_REQUEST, json::Error::from(err))
+            }
+            Self::Auth(err) => {
+                (StatusCode::UNAUTHORIZED, json::Error::from(err))
+            }
+        };
+        (code, Json(value)).into_response()
+    }
+}

examples/login_with_token_csr_only/server/src/application.rs

@@ -0,0 +1,159 @@
+use mailparse::addrparse;
+use pwhash::bcrypt;
+use std::{collections::HashMap, str::FromStr, sync::RwLock};
+use thiserror::Error;
+use uuid::Uuid;
+
+#[derive(Default)]
+pub struct AppState {
+    users: RwLock<HashMap<EmailAddress, Password>>,
+    tokens: RwLock<HashMap<Uuid, EmailAddress>>,
+}
+
+impl AppState {
+    pub fn create_user(
+        &self,
+        credentials: Credentials,
+    ) -> Result<(), CreateUserError> {
+        let Credentials { email, password } = credentials;
+        let user_exists = self.users.read().unwrap().get(&email).is_some();
+        if user_exists {
+            return Err(CreateUserError::UserExists);
+        }
+        self.users.write().unwrap().insert(email, password);
+        Ok(())
+    }
+
+    pub fn login(
+        &self,
+        email: EmailAddress,
+        password: &str,
+    ) -> Result<Uuid, LoginError> {
+        let valid_credentials = self
+            .users
+            .read()
+            .unwrap()
+            .get(&email)
+            .map(|hashed_password| hashed_password.verify(password))
+            .unwrap_or(false);
+        if !valid_credentials {
+            Err(LoginError::InvalidEmailOrPassword)
+        } else {
+            let token = Uuid::new_v4();
+            self.tokens.write().unwrap().insert(token, email);
+            Ok(token)
+        }
+    }
+
+    pub fn logout(&self, token: &str) -> Result<(), LogoutError> {
+        let token = token
+            .parse::<Uuid>()
+            .map_err(|_| LogoutError::NotLoggedIn)?;
+        self.tokens.write().unwrap().remove(&token);
+        Ok(())
+    }
+
+    pub fn authorize_user(
+        &self,
+        token: &str,
+    ) -> Result<CurrentUser, AuthError> {
+        token
+            .parse::<Uuid>()
+            .map_err(|_| AuthError::NotAuthorized)
+            .and_then(|token| {
+                self.tokens
+                    .read()
+                    .unwrap()
+                    .get(&token)
+                    .cloned()
+                    .map(|email| CurrentUser { email, token })
+                    .ok_or(AuthError::NotAuthorized)
+            })
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum CreateUserError {
+    #[error("The user already exists")]
+    UserExists,
+}
+
+#[derive(Debug, Error)]
+pub enum LoginError {
+    #[error("Invalid email or password")]
+    InvalidEmailOrPassword,
+}
+
+#[derive(Debug, Error)]
+pub enum LogoutError {
+    #[error("You are not logged in")]
+    NotLoggedIn,
+}
+
+#[derive(Debug, Error)]
+pub enum AuthError {
+    #[error("You are not authorized")]
+    NotAuthorized,
+}
+
+pub struct Credentials {
+    pub email: EmailAddress,
+    pub password: Password,
+}
+
+#[derive(Clone, Eq, PartialEq, Hash)]
+pub struct EmailAddress(String);
+
+#[derive(Debug, Error)]
+#[error("The given email address is invalid")]
+pub struct InvalidEmailAddress;
+
+impl FromStr for EmailAddress {
+    type Err = InvalidEmailAddress;
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        addrparse(s)
+            .ok()
+            .and_then(|parsed| parsed.extract_single_info())
+            .map(|single_info| Self(single_info.addr))
+            .ok_or(InvalidEmailAddress)
+    }
+}
+
+impl EmailAddress {
+    pub fn into_string(self) -> String {
+        self.0
+    }
+}
+
+#[derive(Clone)]
+pub struct CurrentUser {
+    pub email: EmailAddress,
+    pub token: Uuid,
+}
+
+const MIN_PASSWORD_LEN: usize = 3;
+
+pub struct Password(String);
+
+impl Password {
+    pub fn verify(&self, password: &str) -> bool {
+        bcrypt::verify(password, &self.0)
+    }
+}
+
+#[derive(Debug, Error)]
+pub enum InvalidPassword {
+    #[error("Password is too short (min. length is {0})")]
+    TooShort(usize),
+}
+
+impl TryFrom<String> for Password {
+    type Error = InvalidPassword;
+    fn try_from(p: String) -> Result<Self, Self::Error> {
+        if p.len() < MIN_PASSWORD_LEN {
+            return Err(InvalidPassword::TooShort(MIN_PASSWORD_LEN));
+        }
+        let hashed = bcrypt::hash(&p).unwrap();
+        Ok(Self(hashed))
+    }
+}

examples/login_with_token_csr_only/server/src/main.rs

@@ -0,0 +1,113 @@
+use std::{env, sync::Arc};
+
+use axum::{
+    extract::{State, TypedHeader},
+    headers::{authorization::Bearer, Authorization},
+    http::Method,
+    response::Json,
+    routing::{get, post},
+    Router,
+};
+use tower_http::cors::{Any, CorsLayer};
+
+use api_boundary as json;
+
+mod adapters;
+mod application;
+
+use self::application::*;
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    if let Err(err) = env::var("RUST_LOG") {
+        match err {
+            env::VarError::NotPresent => {
+                env::set_var("RUST_LOG", "debug");
+            }
+            env::VarError::NotUnicode(_) => {
+                return Err(anyhow::anyhow!("The value of 'RUST_LOG' does not contain valid unicode data."));
+            }
+        }
+    }
+    env_logger::init();
+
+    let shared_state = Arc::new(AppState::default());
+
+    let cors_layer = CorsLayer::new()
+        .allow_methods([Method::GET, Method::POST])
+        .allow_origin(Any);
+
+    let app = Router::new()
+        .route("/login", post(login))
+        .route("/logout", post(logout))
+        .route("/users", post(create_user))
+        .route("/users", get(get_user_info))
+        .route_layer(cors_layer)
+        .with_state(shared_state);
+
+    let addr = "0.0.0.0:3000".parse().unwrap();
+    log::info!("Listen on {addr}");
+    axum::Server::bind(&addr)
+        .serve(app.into_make_service())
+        .await?;
+    Ok(())
+}
+
+type Result<T> = std::result::Result<Json<T>, Error>;
+
+/// API error
+#[derive(thiserror::Error, Debug)]
+#[non_exhaustive]
+enum Error {
+    #[error(transparent)]
+    CreateUser(#[from] CreateUserError),
+    #[error(transparent)]
+    Login(#[from] LoginError),
+    #[error(transparent)]
+    Logout(#[from] LogoutError),
+    #[error(transparent)]
+    Auth(#[from] AuthError),
+    #[error(transparent)]
+    Credentials(#[from] adapters::CredentialParsingError),
+}
+
+async fn create_user(
+    State(state): State<Arc<AppState>>,
+    Json(credentials): Json<json::Credentials>,
+) -> Result<()> {
+    let credentials = Credentials::try_from(credentials)?;
+    state.create_user(credentials)?;
+    Ok(Json(()))
+}
+
+async fn login(
+    State(state): State<Arc<AppState>>,
+    Json(credentials): Json<json::Credentials>,
+) -> Result<json::ApiToken> {
+    let json::Credentials { email, password } = credentials;
+    log::debug!("{email} tries to login");
+    let email = email.parse().map_err(|_|
+          // Here we don't want to leak detailed info.
+          LoginError::InvalidEmailOrPassword)?;
+    let token = state.login(email, &password).map(|s| s.to_string())?;
+    Ok(Json(json::ApiToken { token }))
+}
+
+async fn logout(
+    State(state): State<Arc<AppState>>,
+    TypedHeader(auth): TypedHeader<Authorization<Bearer>>,
+) -> Result<()> {
+    state.logout(auth.token())?;
+    Ok(Json(()))
+}
+
+async fn get_user_info(
+    State(state): State<Arc<AppState>>,
+    TypedHeader(auth): TypedHeader<Authorization<Bearer>>,
+) -> Result<json::UserInfo> {
+    let user = state.authorize_user(auth.token())?;
+    let CurrentUser { email, .. } = user;
+    Ok(Json(json::UserInfo {
+        email: email.into_string(),
+    }))
+}

examples/parent_child/Cargo.toml

@@ -8,4 +8,4 @@ leptos = { path = "../../leptos" }
 console_log = "0.2"
 log = "0.4"
 console_error_panic_hook = "0.1.7"
-
+web-sys = "0.3"

examples/parent_child/src/lib.rs

@@ -7,7 +7,8 @@ use web_sys::MouseEvent;
 //    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
-// 4) <ButtonC/>: providing a context that is used in the component (rather than prop drilling)
+// 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>);
@@ -17,6 +18,7 @@ pub fn App(cx: Scope) -> impl IntoView {
     // just some signals to toggle three classes on our <p>
     let (red, set_red) = create_signal(cx, false);
     let (right, set_right) = create_signal(cx, false);
+    let (italics, set_italics) = create_signal(cx, false);
     let (smallcaps, set_smallcaps) = create_signal(cx, false);
 
     // the newtype pattern isn't *necessary* here but is a good practice
@@ -31,6 +33,7 @@ pub fn App(cx: Scope) -> impl IntoView {
                 // 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."
@@ -42,8 +45,13 @@ pub fn App(cx: Scope) -> impl IntoView {
             // 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
-            <ButtonC/>
+            <ButtonD/>
         </main>
     }
 }
@@ -53,7 +61,7 @@ pub fn App(cx: Scope) -> impl IntoView {
 pub fn ButtonA(
     cx: Scope,
     /// Signal that will be toggled when the button is clicked.
-    setter: WriteSignal<bool>
+    setter: WriteSignal<bool>,
 ) -> impl IntoView {
     view! {
         cx,
@@ -70,7 +78,7 @@ pub fn ButtonA(
 pub fn ButtonB<F>(
     cx: Scope,
     /// Callback that will be invoked when the button is clicked.
-    on_click: F
+    on_click: F,
 ) -> impl IntoView
 where
     F: Fn(MouseEvent) + 'static,
@@ -97,10 +105,22 @@ where
     // 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(cx: Scope) -> impl IntoView {
+    view! {
+        cx,
+        <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 ButtonC(cx: Scope) -> impl IntoView {
+pub fn ButtonD(cx: Scope) -> impl IntoView {
     let setter = use_context::<SmallcapsContext>(cx).unwrap().0;
 
     view! {

examples/router/src/lib.rs

@@ -1,14 +1,18 @@
 mod api;
-
+use crate::api::*;
 use leptos::*;
 use leptos_router::*;
 
-use crate::api::{get_contact, get_contacts};
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+struct ExampleContext(i32);
 
 #[component]
 pub fn RouterExample(cx: Scope) -> impl IntoView {
     log::debug!("rendering <RouterExample/>");
 
+    // contexts are passed down through the route tree
+    provide_context(cx, ExampleContext(0));
+
     view! { cx,
         <Router>
             <nav>
@@ -59,10 +63,18 @@ pub fn RouterExample(cx: Scope) -> impl IntoView {
 pub fn ContactList(cx: Scope) -> impl IntoView {
     log::debug!("rendering <ContactList/>");
 
+    // contexts are passed down through the route tree
+    provide_context(cx, ExampleContext(42));
+
+    on_cleanup(cx, || {
+        log!("cleaning up <ContactList/>");
+    });
+
     let location = use_location(cx);
-    let contacts = create_resource(cx, move || location.search.get(), get_contacts);
+    let contacts =
+        create_resource(cx, move || location.search.get(), get_contacts);
     let contacts = move || {
-        contacts.read().map(|contacts| {
+        contacts.read(cx).map(|contacts| {
             // this data doesn't change frequently so we can use .map().collect() instead of a keyed <For/>
             contacts
                 .into_iter()
@@ -95,6 +107,15 @@ pub struct ContactParams {
 pub fn Contact(cx: Scope) -> impl IntoView {
     log::debug!("rendering <Contact/>");
 
+    log::debug!(
+        "ExampleContext should be Some(42). It is {:?}",
+        use_context::<ExampleContext>(cx)
+    );
+
+    on_cleanup(cx, || {
+        log!("cleaning up <Contact/>");
+    });
+
     let params = use_params::<ContactParams>(cx);
     let contact = create_resource(
         cx,
@@ -106,12 +127,19 @@ pub fn Contact(cx: Scope) -> impl IntoView {
         get_contact,
     );
 
-    let contact_display = move || match contact.read() {
+    create_effect(cx, move |_| {
+        log!("params = {:#?}", params.get());
+    });
+
+    let contact_display = move || match contact.read(cx) {
         // None => loading, but will be caught by Suspense fallback
         // I'm only doing this explicitly for the example
         None => None,
         // Some(None) => has loaded and found no contact
-        Some(None) => Some(view! { cx, <p>"No contact with this ID was found."</p> }.into_any()),
+        Some(None) => Some(
+            view! { cx, <p>"No contact with this ID was found."</p> }
+                .into_any(),
+        ),
         // Some(Some) => has loaded and found a contact
         Some(Some(contact)) => Some(
             view! { cx,
@@ -136,6 +164,16 @@ pub fn Contact(cx: Scope) -> impl IntoView {
 #[component]
 pub fn About(cx: Scope) -> impl IntoView {
     log::debug!("rendering <About/>");
+
+    on_cleanup(cx, || {
+        log!("cleaning up <About/>");
+    });
+
+    log::debug!(
+        "ExampleContext should be Some(0). It is {:?}",
+        use_context::<ExampleContext>(cx)
+    );
+
     // use_navigate allows you to navigate programmatically by calling a function
     let navigate = use_navigate(cx);
 
@@ -157,6 +195,11 @@ pub fn About(cx: Scope) -> impl IntoView {
 #[component]
 pub fn Settings(cx: Scope) -> impl IntoView {
     log::debug!("rendering <Settings/>");
+
+    on_cleanup(cx, || {
+        log!("cleaning up <Settings/>");
+    });
+
     view! { cx,
         <>
             <h1>"Settings"</h1>

examples/router/src/main.rs

@@ -2,7 +2,6 @@ use leptos::*;
 use router::*;
 
 pub fn main() {
-    console_error_panic_hook::set_once();
     _ = console_log::init_with_level(log::Level::Debug);
     console_error_panic_hook::set_once();
     mount_to_body(|cx| view! { cx, <RouterExample/> })

examples/session_auth_axum/.envrc

@@ -0,0 +1 @@
+use flake