Merge pull request #1562 from ehuss/bump-version

Update to 0.4.9

.github/workflows/main.yml

@@ -31,7 +31,7 @@ jobs:
             rust: stable
           - build: msrv
             os: ubuntu-latest
-            rust: 1.39.0
+            rust: 1.42.0
     steps:
     - uses: actions/checkout@master
     - name: Install Rust

CHANGELOG.md

@@ -1,5 +1,43 @@
 # Changelog
 
+## mdBook 0.4.9
+[7e01cf9...d325c60](https://github.com/rust-lang/mdBook/compare/7e01cf9...d325c60)
+
+### Changed
+- Updated all dependencies and raised the minimum Rust version to 1.42.
+  [#1528](https://github.com/rust-lang/mdBook/pull/1528)
+- Added more detail to error message when a preprocessor fails.
+  [#1526](https://github.com/rust-lang/mdBook/pull/1526)
+- Set max-width of HTML video tags to 100% to match img tags.
+  [#1542](https://github.com/rust-lang/mdBook/pull/1542)
+
+### Fixed
+- Type errors when parsing `book.toml` are no longer ignored.
+  [#1539](https://github.com/rust-lang/mdBook/pull/1539)
+- Better handling if `mdbook serve` fails to start the http server.
+  [#1555](https://github.com/rust-lang/mdBook/pull/1555)
+- Fixed the path for `edit-url-template` if the book used a source directory
+  other than `src`.
+  [#1554](https://github.com/rust-lang/mdBook/pull/1554)
+
+## mdBook 0.4.8
+[fcceee4...b592b10](https://github.com/rust-lang/mdBook/compare/fcceee4...b592b10)
+
+### Added
+- Added the option `output.html.edit-url-template` which can be a URL which is
+  linked on each page to direct the user to a site (such as GitHub) where the
+  user can directly suggest an edit for the page they are currently reading.
+  [#1506](https://github.com/rust-lang/mdBook/pull/1506)
+
+### Changed
+- Printed output now includes a page break between chapters.
+  [#1485](https://github.com/rust-lang/mdBook/pull/1485)
+
+### Fixed
+- HTML, such as HTML comments, is now ignored if it appears above the title line
+  in `SUMMARY.md`.
+  [#1437](https://github.com/rust-lang/mdBook/pull/1437)
+
 ## mdBook 0.4.7
 [9a9eb01...c83bbd6](https://github.com/rust-lang/mdBook/compare/9a9eb01...c83bbd6)
 

CONTRIBUTING.md

@@ -79,7 +79,7 @@ For more information, such as running it from your favourite editor, please see
 
 #### Finding Issues with Clippy
 
-Clippy is a code analyser/linter detecting mistakes, and therfore helps to improve your code.
+Clippy is a code analyser/linter detecting mistakes, and therefore helps to improve your code.
 Like formatting your code with `rustfmt`, running clippy regularly and before your Pull Request will
 help us maintain awesome code.
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mdbook"
-version = "0.4.7"
+version = "0.4.9"
 authors = [
     "Mathieu David <mathieudavid@mathieudavid.org>",
     "Michael-F-Bryan <michaelfbryan@gmail.com>",
@@ -49,6 +49,7 @@ ammonia = { version = "3", optional = true }
 
 [dev-dependencies]
 select = "0.5"
+semver = "0.11.0"
 pretty_assertions = "0.6"
 walkdir = "2.0"
 

examples/nop-preprocessor.rs

@@ -3,6 +3,7 @@ use clap::{App, Arg, ArgMatches, SubCommand};
 use mdbook::book::Book;
 use mdbook::errors::Error;
 use mdbook::preprocess::{CmdPreprocessor, Preprocessor, PreprocessorContext};
+use semver::{Version, VersionReq};
 use std::io;
 use std::process;
 
@@ -33,9 +34,10 @@ fn main() {
 fn handle_preprocessing(pre: &dyn Preprocessor) -> Result<(), Error> {
     let (ctx, book) = CmdPreprocessor::parse_input(io::stdin())?;
 
-    if ctx.mdbook_version != mdbook::MDBOOK_VERSION {
-        // We should probably use the `semver` crate to check compatibility
-        // here...
+    let book_version = Version::parse(&ctx.mdbook_version)?;
+    let version_req = VersionReq::parse(mdbook::MDBOOK_VERSION)?;
+
+    if version_req.matches(&book_version) != true {
         eprintln!(
             "Warning: The {} plugin was built against version {} of mdbook, \
              but we're being called from version {}",

guide/book.toml

@@ -11,6 +11,7 @@ edition = "2018"
 mathjax-support = true
 site-url = "/mdBook/"
 git-repository-url = "https://github.com/rust-lang/mdBook/tree/master/guide"
+edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"
 
 [output.html.playground]
 editable = true
@@ -24,3 +25,6 @@ boost-hierarchy = 2
 boost-paragraph = 1
 expand = true
 heading-split-level = 2
+
+[output.html.redirect]
+"/format/config.html" = "configuration/index.html"

guide/src/SUMMARY.md

@@ -11,7 +11,11 @@
 - [Format](format/README.md)
     - [SUMMARY.md](format/summary.md)
         - [Draft chapter]()
-    - [Configuration](format/config.md)
+    - [Configuration](format/configuration/README.md)
+        - [General](format/configuration/general.md)
+        - [Preprocessors](format/configuration/preprocessors.md)
+        - [Renderers](format/configuration/renderers.md)
+        - [Environment Variables](format/configuration/environment-variables.md)
     - [Theme](format/theme/README.md)
         - [index.hbs](format/theme/index-hbs.md)
         - [Syntax highlighting](format/theme/syntax-highlighting.md)

guide/src/cli/build.md

@@ -7,7 +7,8 @@ mdbook build
 ```
 
 It will try to parse your `SUMMARY.md` file to understand the structure of your
-book and fetch the corresponding files.
+book and fetch the corresponding files. Note that files mentioned in `SUMMARY.md`
+but not present will be created.
 
 The rendered output will maintain the same directory structure as the source for
 convenience. Large books will therefore remain structured when rendered.

guide/src/cli/init.md

@@ -25,9 +25,9 @@ book-test/
 - The `book` directory is where your book is rendered. All the output is ready
   to be uploaded to a server to be seen by your audience.
 
-- The `SUMMARY.md` file is the most important file, it's the skeleton of your
-  book and is discussed in more detail [in another
-  chapter](../format/summary.md)
+- The `SUMMARY.md` is the skeleton of your
+  book, and is discussed in more detail [in another
+  chapter](../format/summary.md).
 
 #### Tip: Generate chapters from SUMMARY.md
 

guide/src/cli/serve.md

@@ -1,8 +1,15 @@
 # The serve command
 
-The serve command is used to preview a book by serving it over HTTP at
-`localhost:3000` by default. Additionally it watches the book's directory for
-changes, rebuilding the book and refreshing clients for each change. A websocket
+The serve command is used to preview a book by serving it via HTTP at
+`localhost:3000` by default: 
+
+```bash
+mdbook serve
+```
+
+The `serve` command  watches the book's `src` directory for
+changes, rebuilding the book and refreshing clients for each change; this includes
+re-creating deleted files still mentioned in `SUMMARY.md`! A websocket
 connection is used to trigger the client-side refresh.
 
 ***Note:*** *The `serve` command is for testing a book's HTML output, and is not
@@ -17,24 +24,14 @@ root instead of the current working directory.
 mdbook serve path/to/book
 ```
 
-#### Server options
+### Server options
 
-`serve` has four options: the HTTP port, the WebSocket port, the HTTP hostname
-to listen on, and the hostname for the browser to connect to for WebSockets.
-
-For example: suppose you have an nginx server for SSL termination which has a
-public address of 192.168.1.100 on port 80 and proxied that to 127.0.0.1 on port
-8000\. To run use the nginx proxy do:
+The `serve` hostname defaults to `localhost`, and the port defaults to `3000`. Either option can be specified on the command line:
 
 ```bash
-mdbook serve path/to/book -p 8000 -n 127.0.0.1 --websocket-hostname 192.168.1.100
+mdbook serve path/to/book -p 8000 -n 127.0.0.1 
 ```
 
-If you were to want live reloading for this you would need to proxy the
-websocket calls through nginx as well from `192.168.1.100:<WS_PORT>` to
-`127.0.0.1:<WS_PORT>`. The `-w` flag allows for the websocket port to be
-configured.
-
 #### --open
 
 When you use the `--open` (`-o`) flag, mdbook will open the book in your
@@ -55,5 +52,5 @@ contain file patterns described in the [gitignore
 documentation](https://git-scm.com/docs/gitignore). This can be useful for
 ignoring temporary files created by some editors.
 
-_Note: Only `.gitignore` from book root directory is used. Global
-`$HOME/.gitignore` or `.gitignore` files in parent directories are not used._
+***Note:*** *Only the `.gitignore` from the book root directory is used. Global
+`$HOME/.gitignore` or `.gitignore` files in parent directories are not used.*

guide/src/cli/watch.md

@@ -3,7 +3,8 @@
 The `watch` command is useful when you want your book to be rendered on every
 file change. You could repeatedly issue `mdbook build` every time a file is
 changed. But using `mdbook watch` once will watch your files and will trigger a
-build automatically whenever you modify a file.
+build automatically whenever you modify a file; this includes re-creating
+deleted files still mentioned in `SUMMARY.md`!
 
 #### Specify a directory
 

guide/src/continuous-integration.md

@@ -133,7 +133,7 @@ stages:
 
 pages:
   stage: deploy
-  image: rust:alpine
+  image: rust
   variables:
     CARGO_HOME: $CI_PROJECT_DIR/cargo
   before_script:

guide/src/for_developers/preprocessors.md

@@ -18,9 +18,9 @@ A new table is added to `book.toml` (e.g. `preprocessor.foo` for the `foo`
 preprocessor) and then `mdbook` will try to invoke the `mdbook-foo` program as
 part of the build process.
 
-While preprocessors can be hard-coded to specify which backend it should be run
-for (e.g. it doesn't make sense for MathJax to be used for non-HTML renderers)
-with the `preprocessor.foo.renderer` key.
+A preprocessor can be hard-coded to specify which backend(s) it should be run
+for with the `preprocessor.foo.renderer` key. For example, it doesn't make sense for 
+[MathJax](../format/mathjax.md) to be used for non-HTML renderers.
 
 ```toml
 [book]

guide/src/format/configuration/README.md

@@ -0,0 +1,12 @@
+# Configuration
+
+This section details the configuration options available in the ***book.toml***:
+- **[General]** configuration including the `book`, `rust`, `build` sections
+- **[Preprocessor]** configuration for default and custom book preprocessors
+- **[Renderer]** configuration for the HTML, Markdown and custom renderers
+- **[Environment Variable]** configuration for overriding configuration options in your environment
+
+[General]: general.md
+[Preprocessor]: preprocessors.md
+[Renderer]: renderers.md
+[Environment Variable]: environment-variables.md

guide/src/format/configuration/environment-variables.md

@@ -0,0 +1,38 @@
+# Environment Variables
+
+All configuration values can be overridden from the command line by setting the
+corresponding environment variable. Because many operating systems restrict
+environment variables to be alphanumeric characters or `_`, the configuration
+key needs to be formatted slightly differently to the normal `foo.bar.baz` form.
+
+Variables starting with `MDBOOK_` are used for configuration. The key is created
+by removing the `MDBOOK_` prefix and turning the resulting string into
+`kebab-case`. Double underscores (`__`) separate nested keys, while a single
+underscore (`_`) is replaced with a dash (`-`).
+
+For example:
+
+- `MDBOOK_foo` -> `foo`
+- `MDBOOK_FOO` -> `foo`
+- `MDBOOK_FOO__BAR` -> `foo.bar`
+- `MDBOOK_FOO_BAR` -> `foo-bar`
+- `MDBOOK_FOO_bar__baz` -> `foo-bar.baz`
+
+So by setting the `MDBOOK_BOOK__TITLE` environment variable you can override the
+book's title without needing to touch your `book.toml`.
+
+> **Note:** To facilitate setting more complex config items, the value of an
+> environment variable is first parsed as JSON, falling back to a string if the
+> parse fails.
+>
+> This means, if you so desired, you could override all book metadata when
+> building the book with something like
+>
+> ```shell
+> $ export MDBOOK_BOOK="{'title': 'My Awesome Book', authors: ['Michael-F-Bryan']}"
+> $ mdbook build
+> ```
+
+The latter case may be useful in situations where `mdbook` is invoked from a
+script or CI, where it sometimes isn't possible to update the `book.toml` before
+building.

guide/src/format/configuration/general.md

@@ -0,0 +1,97 @@
+# General Configuration
+
+You can configure the parameters for your book in the ***book.toml*** file.
+
+Here is an example of what a ***book.toml*** file might look like:
+
+```toml
+[book]
+title = "Example book"
+author = "John Doe"
+description = "The example book covers examples."
+
+[rust]
+edition = "2018"
+
+[build]
+build-dir = "my-example-book"
+create-missing = false
+
+[preprocessor.index]
+
+[preprocessor.links]
+
+[output.html]
+additional-css = ["custom.css"]
+
+[output.html.search]
+limit-results = 15
+```
+
+## Supported configuration options
+
+It is important to note that **any** relative path specified in the
+configuration will always be taken relative from the root of the book where the
+configuration file is located.
+
+### General metadata
+
+This is general information about your book.
+
+- **title:** The title of the book
+- **authors:** The author(s) of the book
+- **description:** A description for the book, which is added as meta
+  information in the html `<head>` of each page
+- **src:** By default, the source directory is found in the directory named
+  `src` directly under the root folder. But this is configurable with the `src`
+  key in the configuration file.
+- **language:** The main language of the book, which is used as a language attribute `<html lang="en">` for example.
+
+**book.toml**
+```toml
+[book]
+title = "Example book"
+authors = ["John Doe", "Jane Doe"]
+description = "The example book covers examples."
+src = "my-src"  # the source files will be found in `root/my-src` instead of `root/src`
+language = "en"
+```
+
+### Rust options
+
+Options for the Rust language, relevant to running tests and playground
+integration.
+
+- **edition**: Rust edition to use by default for the code snippets. Default
+  is "2015". Individual code blocks can be controlled with the `edition2015`
+  or `edition2018` annotations, such as:
+
+  ~~~text
+  ```rust,edition2015
+  // This only works in 2015.
+  let try = true;
+  ```
+  ~~~
+
+### Build options
+
+This controls the build process of your book.
+
+- **build-dir:** The directory to put the rendered book in. By default this is
+  `book/` in the book's root directory.
+- **create-missing:** By default, any missing files specified in `SUMMARY.md`
+  will be created when the book is built (i.e. `create-missing = true`). If this
+  is `false` then the build process will instead exit with an error if any files
+  do not exist.
+- **use-default-preprocessors:** Disable the default preprocessors of (`links` &
+  `index`) by setting this option to `false`.
+
+  If you have the same, and/or other preprocessors declared via their table
+  of configuration, they will run instead.
+
+  - For clarity, with no preprocessor configuration, the default `links` and
+    `index` will run.
+  - Setting `use-default-preprocessors = false` will disable these
+    default preprocessors from running.
+  - Adding `[preprocessor.links]`, for example, will ensure, regardless of
+    `use-default-preprocessors` that `links` it will run.

guide/src/format/configuration/preprocessors.md

@@ -0,0 +1,58 @@
+# Configuring Preprocessors
+
+The following preprocessors are available and included by default:
+
+- `links`: Expand the `{{ #playground }}`, `{{ #include }}`, and `{{ #rustdoc_include }}` handlebars
+  helpers in a chapter to include the contents of a file.
+- `index`: Convert all chapter files named `README.md` into `index.md`. That is
+  to say, all `README.md` would be rendered to an index file `index.html` in the
+  rendered book.
+
+
+**book.toml**
+```toml
+[build]
+build-dir = "build"
+create-missing = false
+
+[preprocessor.links]
+
+[preprocessor.index]
+```
+
+### Custom Preprocessor Configuration
+
+Like renderers, preprocessor will need to be given its own table (e.g.
+`[preprocessor.mathjax]`). In the section, you may then pass extra
+configuration to the preprocessor by adding key-value pairs to the table.
+
+For example
+
+```toml
+[preprocessor.links]
+# set the renderers this preprocessor will run for
+renderers = ["html"]
+some_extra_feature = true
+```
+
+#### Locking a Preprocessor dependency to a renderer
+
+You can explicitly specify that a preprocessor should run for a renderer by
+binding the two together.
+
+```toml
+[preprocessor.mathjax]
+renderers = ["html"]  # mathjax only makes sense with the HTML renderer
+```
+
+### Provide Your Own Command
+
+By default when you add a `[preprocessor.foo]` table to your `book.toml` file,
+`mdbook` will try to invoke the `mdbook-foo` executable. If you want to use a
+different program name or pass in command-line arguments, this behaviour can
+be overridden by adding a `command` field.
+
+```toml
+[preprocessor.random]
+command = "python random.py"
+```

guide/src/format/configuration/renderers.md

@@ -1,161 +1,4 @@
-# Configuration
-
-You can configure the parameters for your book in the ***book.toml*** file.
-
-Here is an example of what a ***book.toml*** file might look like:
-
-```toml
-[book]
-title = "Example book"
-author = "John Doe"
-description = "The example book covers examples."
-
-[rust]
-edition = "2018"
-
-[build]
-build-dir = "my-example-book"
-create-missing = false
-
-[preprocessor.index]
-
-[preprocessor.links]
-
-[output.html]
-additional-css = ["custom.css"]
-
-[output.html.search]
-limit-results = 15
-```
-
-## Supported configuration options
-
-It is important to note that **any** relative path specified in the
-configuration will always be taken relative from the root of the book where the
-configuration file is located.
-
-### General metadata
-
-This is general information about your book.
-
-- **title:** The title of the book
-- **authors:** The author(s) of the book
-- **description:** A description for the book, which is added as meta
-  information in the html `<head>` of each page
-- **src:** By default, the source directory is found in the directory named
-  `src` directly under the root folder. But this is configurable with the `src`
-  key in the configuration file.
-- **language:** The main language of the book, which is used as a language attribute `<html lang="en">` for example.
-
-**book.toml**
-```toml
-[book]
-title = "Example book"
-authors = ["John Doe", "Jane Doe"]
-description = "The example book covers examples."
-src = "my-src"  # the source files will be found in `root/my-src` instead of `root/src`
-language = "en"
-```
-
-### Rust options
-
-Options for the Rust language, relevant to running tests and playground
-integration.
-
-- **edition**: Rust edition to use by default for the code snippets. Default
-  is "2015". Individual code blocks can be controlled with the `edition2015`
-  or `edition2018` annotations, such as:
-
-  ~~~text
-  ```rust,edition2015
-  // This only works in 2015.
-  let try = true;
-  ```
-  ~~~
-
-### Build options
-
-This controls the build process of your book.
-
-- **build-dir:** The directory to put the rendered book in. By default this is
-  `book/` in the book's root directory.
-- **create-missing:** By default, any missing files specified in `SUMMARY.md`
-  will be created when the book is built (i.e. `create-missing = true`). If this
-  is `false` then the build process will instead exit with an error if any files
-  do not exist.
-- **use-default-preprocessors:** Disable the default preprocessors of (`links` &
-  `index`) by setting this option to `false`.
-
-  If you have the same, and/or other preprocessors declared via their table
-  of configuration, they will run instead.
-
-  - For clarity, with no preprocessor configuration, the default `links` and
-    `index` will run.
-  - Setting `use-default-preprocessors = false` will disable these
-    default preprocessors from running.
-  - Adding `[preprocessor.links]`, for example, will ensure, regardless of
-    `use-default-preprocessors` that `links` it will run.
-
-## Configuring Preprocessors
-
-The following preprocessors are available and included by default:
-
-- `links`: Expand the `{{ #playground }}`, `{{ #include }}`, and `{{ #rustdoc_include }}` handlebars
-  helpers in a chapter to include the contents of a file.
-- `index`: Convert all chapter files named `README.md` into `index.md`. That is
-  to say, all `README.md` would be rendered to an index file `index.html` in the
-  rendered book.
-
-
-**book.toml**
-```toml
-[build]
-build-dir = "build"
-create-missing = false
-
-[preprocessor.links]
-
-[preprocessor.index]
-```
-
-### Custom Preprocessor Configuration
-
-Like renderers, preprocessor will need to be given its own table (e.g.
-`[preprocessor.mathjax]`). In the section, you may then pass extra
-configuration to the preprocessor by adding key-value pairs to the table.
-
-For example
-
-```toml
-[preprocessor.links]
-# set the renderers this preprocessor will run for
-renderers = ["html"]
-some_extra_feature = true
-```
-
-#### Locking a Preprocessor dependency to a renderer
-
-You can explicitly specify that a preprocessor should run for a renderer by
-binding the two together.
-
-```toml
-[preprocessor.mathjax]
-renderers = ["html"]  # mathjax only makes sense with the HTML renderer
-```
-
-### Provide Your Own Command
-
-By default when you add a `[preprocessor.foo]` table to your `book.toml` file,
-`mdbook` will try to invoke the `mdbook-foo` executable. If you want to use a
-different program name or pass in command-line arguments, this behaviour can
-be overridden by adding a `command` field.
-
-```toml
-[preprocessor.random]
-command = "python random.py"
-```
-
-## Configuring Renderers
+# Configuring Renderers
 
 ### HTML renderer options
 
@@ -175,7 +18,7 @@ The following configuration options are available:
   CSS media query. Defaults to `navy`.
 - **curly-quotes:** Convert straight quotes to curly quotes, except for those
   that occur in code blocks and code spans. Defaults to `false`.
-- **mathjax-support:** Adds support for [MathJax](mathjax.md). Defaults to
+- **mathjax-support:** Adds support for [MathJax](../mathjax.md). Defaults to
   `false`.
 - **copy-fonts:** Copies fonts.css and respective font files to the output directory and use them in the default theme. Defaults to `true`.
 - **google-analytics:** If you use Google Analytics, this option lets you enable
@@ -201,13 +44,21 @@ The following configuration options are available:
   an icon link will be output in the menu bar of the book.
 - **git-repository-icon:** The FontAwesome icon class to use for the git
   repository link. Defaults to `fa-github`.
+- **edit-url-template:** Edit url template, when provided shows a
+  "Suggest an edit" button for directly jumping to editing the currently
+  viewed page. For e.g. GitHub projects set this to
+  `https://github.com/<owner>/<repo>/edit/master/{path}` or for
+  Bitbucket projects set it to
+  `https://bitbucket.org/<owner>/<repo>/src/master/{path}?mode=edit`
+  where {path} will be replaced with the full path of the file in the
+  repository.
 - **redirect:** A subtable used for generating redirects when a page is moved.
   The table contains key-value pairs where the key is where the redirect file
   needs to be created, as an absolute path from the build directory, (e.g.
   `/appendices/bibliography.html`). The value can be any valid URI the
   browser should navigate to (e.g. `https://rust-lang.org/`,
   `/overview.html`, or `../bibliography.html`).
-- **input-404:** The name of the markdown file used for misssing files.
+- **input-404:** The name of the markdown file used for missing files.
   The corresponding output file will be the same, with the extension replaced with `html`.
   Defaults to `404.md`.
 - **site-url:** The url where the book will be hosted. This is required to ensure
@@ -286,6 +137,7 @@ additional-js = ["custom.js"]
 no-section-label = false
 git-repository-url = "https://github.com/rust-lang/mdBook"
 git-repository-icon = "fa-github"
+edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"
 site-url = "/example-book/"
 cname = "myproject.rs"
 input-404 = "not-found.md"
@@ -354,43 +206,4 @@ anything under `[output.foo]`). mdBook checks for two common fields:
 - **optional:** If `true`, then the command will be ignored if it is not
   installed, otherwise mdBook will fail with an error. Defaults to `false`.
 
-[alternative backends]: ../for_developers/backends.md
-
-## Environment Variables
-
-All configuration values can be overridden from the command line by setting the
-corresponding environment variable. Because many operating systems restrict
-environment variables to be alphanumeric characters or `_`, the configuration
-key needs to be formatted slightly differently to the normal `foo.bar.baz` form.
-
-Variables starting with `MDBOOK_` are used for configuration. The key is created
-by removing the `MDBOOK_` prefix and turning the resulting string into
-`kebab-case`. Double underscores (`__`) separate nested keys, while a single
-underscore (`_`) is replaced with a dash (`-`).
-
-For example:
-
-- `MDBOOK_foo` -> `foo`
-- `MDBOOK_FOO` -> `foo`
-- `MDBOOK_FOO__BAR` -> `foo.bar`
-- `MDBOOK_FOO_BAR` -> `foo-bar`
-- `MDBOOK_FOO_bar__baz` -> `foo-bar.baz`
-
-So by setting the `MDBOOK_BOOK__TITLE` environment variable you can override the
-book's title without needing to touch your `book.toml`.
-
-> **Note:** To facilitate setting more complex config items, the value of an
-> environment variable is first parsed as JSON, falling back to a string if the
-> parse fails.
->
-> This means, if you so desired, you could override all book metadata when
-> building the book with something like
->
-> ```shell
-> $ export MDBOOK_BOOK="{'title': 'My Awesome Book', authors: ['Michael-F-Bryan']}"
-> $ mdbook build
-> ```
-
-The latter case may be useful in situations where `mdbook` is invoked from a
-script or CI, where it sometimes isn't possible to update the `book.toml` before
-building.
+[alternative backends]: ../../for_developers/backends.md

guide/src/format/example.rs

@@ -1,6 +1,6 @@
 fn main() {
     println!("Hello World!");
 #
-#    // You can even hide lines! :D
-#   println!("I am hidden! Expand the code snippet to see me");
+#     // You can even hide lines! :D
+#     println!("I am hidden! Expand the code snippet to see me");
 }

guide/src/format/mdbook.md

@@ -40,7 +40,7 @@ The path to the file has to be relative from the current source file.
 mdBook will interpret included files as Markdown. Since the include command
 is usually used for inserting code snippets and examples, you will often
 wrap the command with ```` ``` ```` to display the file contents without
-interpretting them.
+interpreting them.
 
 ````hbs
 ```
@@ -49,7 +49,7 @@ interpretting them.
 ````
 
 ## Including portions of a file
-Often you only need a specific part of the file e.g. relevant lines for an
+Often you only need a specific part of the file, e.g. relevant lines for an
 example. We support four different modes of partial includes:
 
 ```hbs
@@ -68,8 +68,8 @@ consisting of lines 2 to 10.
 To avoid breaking your book when modifying included files, you can also
 include a specific section using anchors instead of line numbers.
 An anchor is a pair of matching lines. The line beginning an anchor must
-match the regex "ANCHOR:\s*[\w_-]+" and similarly the ending line must match
-the regex "ANCHOR_END:\s*[\w_-]+". This allows you to put anchors in
+match the regex `ANCHOR:\s*[\w_-]+` and similarly the ending line must match
+the regex `ANCHOR_END:\s*[\w_-]+`. This allows you to put anchors in
 any kind of commented line.
 
 Consider the following file to include:
@@ -156,7 +156,7 @@ To call the `add_one` function, we pass it an `i32` and bind the returned value
 #
 # fn add_one(num: i32) -> i32 {
 #     num + 1
-#}
+# }
 ```
 ````
 
@@ -170,7 +170,7 @@ That is, it looks like this (click the "expand" icon to see the rest of the file
 #
 # fn add_one(num: i32) -> i32 {
 #     num + 1
-#}
+# }
 ```
 
 ## Inserting runnable Rust files
@@ -192,3 +192,12 @@ Here is what a rendered code snippet looks like:
 {{#playground example.rs}}
 
 [Rust Playground]: https://play.rust-lang.org/
+
+## Controlling page \<title\>
+
+A chapter can set a \<title\> that is different from its entry in the table of
+contents (sidebar) by including a `\{{#title ...}}` near the top of the page.
+
+```hbs
+\{{#title My Title}}
+```

guide/src/format/summary.md

@@ -4,63 +4,96 @@ The summary file is used by mdBook to know what chapters to include, in what
 order they should appear, what their hierarchy is and where the source files
 are. Without this file, there is no book.
 
-Even though `SUMMARY.md` is a markdown file, the formatting is very strict to
-allow for easy parsing. Let's see how you should format your `SUMMARY.md` file.
+This markdown file must be named `SUMMARY.md`. Its formatting
+is very strict and must follow the structure outlined below to allow for easy
+parsing. Any element not specified below, be it formatting or textual, is likely
+to be ignored at best, or may cause an error when attempting to build the book.
 
-#### Structure
+### Structure
 
-1. ***Title*** It's common practice to begin with a title, generally <code
-   class="language-markdown"># Summary</code>. But it is not mandatory, the
-   parser just ignores it. So you can too if you feel like it.
-
-2. ***Prefix Chapter*** Before the main numbered chapters you can add a couple
-   of elements that will not be numbered. This is useful for forewords,
-   introductions, etc. There are however some constraints. You can not nest
-   prefix chapters, they should all be on the root level. And you can not add
-   prefix chapters once you have added numbered chapters.
+1. ***Title*** - While optional, it's common practice to begin with a title, generally <code
+   class="language-markdown"># Summary</code>. This is ignored by the parser however, and
+   can be ommitted.
    ```markdown
-   [Title of prefix element](relative/path/to/markdown.md)
+   # Summary
    ```
 
-3. ***Part Title:*** Headers can be used as a title for the following numbered
+1. ***Prefix Chapter*** - Before the main numbered chapters, prefix chapters can be added
+   that will not be numbered. This is useful for forewords,
+   introductions, etc. There are, however, some constraints. Prefix chapters cannot be
+   nested; they should all be on the root level. And you can not add
+   prefix chapters once you have added numbered chapters.
+   ```markdown
+   [A Prefix Chapter](relative/path/to/markdown.md)
+
+   - [First Chapter](relative/path/to/markdown2.md)
+   ```
+
+1. ***Part Title*** - Headers can be used as a title for the following numbered
    chapters. This can be used to logically separate different sections
-   of book. The title is rendered as unclickable text.
+   of the book. The title is rendered as unclickable text.
    Titles are optional, and the numbered chapters can be broken into as many
    parts as desired.
+   ```markdown
+   # My Part Tile
 
-4. ***Numbered Chapter*** Numbered chapters are the main content of the book,
-   they will be numbered and can be nested, resulting in a nice hierarchy
-   (chapters, sub-chapters, etc.)
+   - [First Chapter](relative/path/to/markdown.md)
+   ```
+
+1. ***Numbered Chapter*** - Numbered chapters outline the main content of the book
+   and can be nested, resulting in a nice hierarchy
+   (chapters, sub-chapters, etc.).
    ```markdown
    # Title of Part
 
-   - [Title of the Chapter](relative/path/to/markdown.md)
+   - [First Chapter](relative/path/to/markdown.md)
+   - [Second Chapter](relative/path/to/markdown2.md)
+      - [Sub Chapter](relative/path/to/markdown3.md)
 
    # Title of Another Part
 
-   - [More Chapters](relative/path/to/markdown2.md)
+   - [Another Chapter](relative/path/to/markdown4.md)
    ```
-   You can either use `-` or `*` to indicate a numbered chapter.
+   Numbered chapters can be denoted with either `-` or `*`.
 
-5. ***Suffix Chapter*** After the numbered chapters you can add a couple of
-   non-numbered chapters. They are the same as prefix chapters but come after
-   the numbered chapters instead of before.
+1. ***Suffix Chapter*** - Like prefix chapters, suffix chapters are unnumbered, but they come after 
+   numbered chapters.
+   ```markdown
+   - [Last Chapter](relative/path/to/markdown.md)
 
-All other elements are unsupported and will be ignored at best or result in an
-error.
+   [Title of Suffix Chapter](relative/path/to/markdown2.md)
+   ```
 
-#### Other elements
+1. ***Draft chapters*** - Draft chapters are chapters without a file and thus content.
+   The purpose of a draft chapter is to signal future chapters still to be written.
+   Or when still laying out the structure of the book to avoid creating the files
+   while you are still changing the structure of the book a lot.
+   Draft chapters will be rendered in the HTML renderer as disabled links in the table
+   of contents, as you can see for the next chapter in the table of contents on the left.
+   Draft chapters are written like normal chapters but without writing the path to the file.
+   ```markdown
+   - [Draft Chapter]()
+   ```
 
-- ***Separators*** In between chapters you can add a separator. In the HTML renderer
-  this will result in a line being rendered in the table of contents. A separator is
-  a line containing exclusively dashes and at least three of them: `---`.
-- ***Draft chapters*** Draft chapters are chapters without a file and thus content.
-  The purpose of a draft chapter is to signal future chapters still to be written.
-  Or when still laying out the structure of the book to avoid creating the files
-  while you are still changing the structure of the book a lot.
-  Draft chapters will be rendered in the HTML renderer as disabled links in the table
-  of contents, as you can see for the next chapter in the table of contents on the left.
-  Draft chapters are written like normal chapters but without writing the path to the file
-  ```markdown
-  - [Draft chapter]()
-  ```
+1. ***Separators*** - Separators can be added before, in between, and after any other element. They result
+   in an HTML rendered line in the built table of contents.  A separator is
+   a line containing exclusively dashes and at least three of them: `---`.
+   ```markdown
+   # My Part Title
+   
+   [A Prefix Chapter](relative/path/to/markdown.md)
+
+   ---
+
+   - [First Chapter](relative/path/to/markdown2.md)
+   ```
+  
+
+### Example
+
+Below is the markdown source for the `SUMMARY.md` for this guide, with the resulting table
+of contents as rendered to the left.
+
+```markdown
+{{#include ../SUMMARY.md}}
+```

guide/src/format/theme/README.md

@@ -42,5 +42,5 @@ If you completely replace all built-in themes, be sure to also set
 [`output.html.preferred-dark-theme`] in the config, which defaults to the
 built-in `navy` theme.
 
-[`output.html.preferred-dark-theme`]: ../config.md#html-renderer-options
+[`output.html.preferred-dark-theme`]: ../configuration/renderers.md#html-renderer-options
 [newer browsers]: https://caniuse.com/#feat=link-icon-svg

guide/src/format/theme/editor.md

@@ -33,7 +33,7 @@ Note the new `Undo Changes` button in the editable playgrounds.
 ## Customizing the Editor
 
 By default, the editor is the [Ace](https://ace.c9.io/) editor, but, if desired,
-the functionality may be overriden by providing a different folder:
+the functionality may be overridden by providing a different folder:
 
 ```toml
 [output.html.playground]
@@ -42,5 +42,5 @@ editor = "/path/to/editor"
 ```
 
 Note that for the editor changes to function correctly, the `book.js` inside of
-the `theme` folder will need to be overriden as it has some couplings with the
+the `theme` folder will need to be overridden as it has some couplings with the
 default Ace editor.

guide/src/misc/contributors.md

@@ -17,5 +17,6 @@ shout-out to them!
 - Matt Ickstadt ([mattico](https://github.com/mattico))
 - Weihang Lo ([@weihanglo](https://github.com/weihanglo))
 - Avision Ho ([@avisionh](https://github.com/avisionh))
+- Vivek Akupatni ([@apatniv](https://github.com/apatniv))
 
 If you feel you're missing from this list, feel free to add yourself in a PR.

src/book/book.rs

@@ -74,10 +74,10 @@ fn create_missing(src_dir: &Path, summary: &Summary) -> Result<()> {
 /// [`iter()`]: #method.iter
 /// [`for_each_mut()`]: #method.for_each_mut
 #[derive(Debug, Clone, Default, PartialEq, Serialize, Deserialize)]
+#[non_exhaustive]
 pub struct Book {
     /// The sections in this book.
     pub sections: Vec<BookItem>,
-    __non_exhaustive: (),
 }
 
 impl Book {
@@ -160,6 +160,8 @@ pub struct Chapter {
     pub sub_items: Vec<BookItem>,
     /// The chapter's location, relative to the `SUMMARY.md` file.
     pub path: Option<PathBuf>,
+    /// The chapter's source file, relative to the `SUMMARY.md` file.
+    pub source_path: Option<PathBuf>,
     /// An ordered list of the names of each chapter above this one in the hierarchy.
     pub parent_names: Vec<String>,
 }
@@ -169,13 +171,15 @@ impl Chapter {
     pub fn new<P: Into<PathBuf>>(
         name: &str,
         content: String,
-        path: P,
+        p: P,
         parent_names: Vec<String>,
     ) -> Chapter {
+        let path: PathBuf = p.into();
         Chapter {
             name: name.to_string(),
             content,
-            path: Some(path.into()),
+            path: Some(path.clone()),
+            source_path: Some(path),
             parent_names,
             ..Default::default()
         }
@@ -188,6 +192,7 @@ impl Chapter {
             name: name.to_string(),
             content: String::new(),
             path: None,
+            source_path: None,
             parent_names,
             ..Default::default()
         }
@@ -195,10 +200,7 @@ impl Chapter {
 
     /// Check if the chapter is a draft chapter, meaning it has no path to a source markdown file.
     pub fn is_draft_chapter(&self) -> bool {
-        match self.path {
-            Some(_) => false,
-            None => true,
-        }
+        self.path.is_none()
     }
 }
 
@@ -223,10 +225,7 @@ pub(crate) fn load_book_from_disk<P: AsRef<Path>>(summary: &Summary, src_dir: P)
         chapters.push(chapter);
     }
 
-    Ok(Book {
-        sections: chapters,
-        __non_exhaustive: (),
-    })
+    Ok(Book { sections: chapters })
 }
 
 fn load_summary_item<P: AsRef<Path> + Clone>(
@@ -438,6 +437,7 @@ And here is some \
             content: String::from("Hello World!"),
             number: Some(SectionNumber(vec![1, 2])),
             path: Some(PathBuf::from("second.md")),
+            source_path: Some(PathBuf::from("second.md")),
             parent_names: vec![String::from("Chapter 1")],
             sub_items: Vec::new(),
         };
@@ -446,6 +446,7 @@ And here is some \
             content: String::from(DUMMY_SRC),
             number: None,
             path: Some(PathBuf::from("chapter_1.md")),
+            source_path: Some(PathBuf::from("chapter_1.md")),
             parent_names: Vec::new(),
             sub_items: vec![
                 BookItem::Chapter(nested.clone()),
@@ -470,6 +471,7 @@ And here is some \
                 name: String::from("Chapter 1"),
                 content: String::from(DUMMY_SRC),
                 path: Some(PathBuf::from("chapter_1.md")),
+                source_path: Some(PathBuf::from("chapter_1.md")),
                 ..Default::default()
             })],
             ..Default::default()
@@ -510,6 +512,7 @@ And here is some \
                     content: String::from(DUMMY_SRC),
                     number: None,
                     path: Some(PathBuf::from("Chapter_1/index.md")),
+                    source_path: Some(PathBuf::from("Chapter_1/index.md")),
                     parent_names: Vec::new(),
                     sub_items: vec![
                         BookItem::Chapter(Chapter::new(
@@ -562,6 +565,7 @@ And here is some \
                     content: String::from(DUMMY_SRC),
                     number: None,
                     path: Some(PathBuf::from("Chapter_1/index.md")),
+                    source_path: Some(PathBuf::from("Chapter_1/index.md")),
                     parent_names: Vec::new(),
                     sub_items: vec![
                         BookItem::Chapter(Chapter::new(

src/book/mod.rs

@@ -196,23 +196,20 @@ impl MDBook {
             }
         }
 
-        info!("Running the {} backend", renderer.name());
-        self.render(&preprocessed_book, renderer)?;
-
-        Ok(())
-    }
-
-    fn render(&self, preprocessed_book: &Book, renderer: &dyn Renderer) -> Result<()> {
         let name = renderer.name();
         let build_dir = self.build_dir_for(name);
 
-        let render_context = RenderContext::new(
+        let mut render_context = RenderContext::new(
             self.root.clone(),
-            preprocessed_book.clone(),
+            preprocessed_book,
             self.config.clone(),
             build_dir,
         );
+        render_context
+            .chapter_titles
+            .extend(preprocess_ctx.chapter_titles.borrow_mut().drain());
 
+        info!("Running the {} backend", renderer.name());
         renderer
             .render(&render_context)
             .with_context(|| "Rendering failed")

src/book/summary.rs

@@ -173,7 +173,7 @@ struct SummaryParser<'a> {
 /// `Event::End` is encountered which matches the `$delimiter` pattern.
 ///
 /// This is the equivalent of doing
-/// `$stream.take_while(|e| e != $delimeter).collect()` but it allows you to
+/// `$stream.take_while(|e| e != $delimiter).collect()` but it allows you to
 /// use pattern matching and you won't get errors because `take_while()`
 /// moves `$stream` out of self.
 macro_rules! collect_events {
@@ -525,14 +525,19 @@ impl<'a> SummaryParser<'a> {
 
     /// Try to parse the title line.
     fn parse_title(&mut self) -> Option<String> {
-        match self.next_event() {
-            Some(Event::Start(Tag::Heading(1))) => {
-                debug!("Found a h1 in the SUMMARY");
+        loop {
+            match self.next_event() {
+                Some(Event::Start(Tag::Heading(1))) => {
+                    debug!("Found a h1 in the SUMMARY");
 
-                let tags = collect_events!(self.stream, end Tag::Heading(1));
-                Some(stringify_events(tags))
+                    let tags = collect_events!(self.stream, end Tag::Heading(1));
+                    return Some(stringify_events(tags));
+                }
+                // Skip a HTML element such as a comment line.
+                Some(Event::Html(_)) => {}
+                // Otherwise, no title.
+                _ => return None,
             }
-            _ => None,
         }
     }
 }
@@ -973,4 +978,103 @@ mod tests {
 
         assert_eq!(got, should_be);
     }
+
+    #[test]
+    fn skip_html_comments() {
+        let src = r#"<!--
+# Title - En
+-->
+# Title - Local
+
+<!--
+[Prefix 00-01 - En](ch00-01.md)
+[Prefix 00-02 - En](ch00-02.md)
+-->
+[Prefix 00-01 - Local](ch00-01.md)
+[Prefix 00-02 - Local](ch00-02.md)
+
+<!--
+## Section Title - En
+-->
+## Section Title - Localized
+
+<!--
+- [Ch 01-00 - En](ch01-00.md)
+    - [Ch 01-01 - En](ch01-01.md)
+    - [Ch 01-02 - En](ch01-02.md)
+-->
+- [Ch 01-00 - Local](ch01-00.md)
+    - [Ch 01-01 - Local](ch01-01.md)
+    - [Ch 01-02 - Local](ch01-02.md)
+
+<!--
+- [Ch 02-00 - En](ch02-00.md)
+-->
+- [Ch 02-00 - Local](ch02-00.md)
+
+<!--
+[Appendix A - En](appendix-01.md)
+[Appendix B - En](appendix-02.md)
+-->`
+[Appendix A - Local](appendix-01.md)
+[Appendix B - Local](appendix-02.md)
+"#;
+
+        let mut parser = SummaryParser::new(src);
+
+        // ---- Title ----
+        let title = parser.parse_title();
+        assert_eq!(title, Some(String::from("Title - Local")));
+
+        // ---- Prefix Chapters ----
+
+        let new_affix_item = |name, location| {
+            SummaryItem::Link(Link {
+                name: String::from(name),
+                location: Some(PathBuf::from(location)),
+                ..Default::default()
+            })
+        };
+
+        let should_be = vec![
+            new_affix_item("Prefix 00-01 - Local", "ch00-01.md"),
+            new_affix_item("Prefix 00-02 - Local", "ch00-02.md"),
+        ];
+
+        let got = parser.parse_affix(true).unwrap();
+        assert_eq!(got, should_be);
+
+        // ---- Numbered Chapters ----
+
+        let new_numbered_item = |name, location, numbers: &[u32], nested_items| {
+            SummaryItem::Link(Link {
+                name: String::from(name),
+                location: Some(PathBuf::from(location)),
+                number: Some(SectionNumber(numbers.to_vec())),
+                nested_items,
+            })
+        };
+
+        let ch01_nested = vec![
+            new_numbered_item("Ch 01-01 - Local", "ch01-01.md", &[1, 1], vec![]),
+            new_numbered_item("Ch 01-02 - Local", "ch01-02.md", &[1, 2], vec![]),
+        ];
+
+        let should_be = vec![
+            new_numbered_item("Ch 01-00 - Local", "ch01-00.md", &[1], ch01_nested),
+            new_numbered_item("Ch 02-00 - Local", "ch02-00.md", &[2], vec![]),
+        ];
+        let got = parser.parse_parts().unwrap();
+        assert_eq!(got, should_be);
+
+        // ---- Suffix Chapters ----
+
+        let should_be = vec![
+            new_affix_item("Appendix A - Local", "appendix-01.md"),
+            new_affix_item("Appendix B - Local", "appendix-02.md"),
+        ];
+
+        let got = parser.parse_affix(false).unwrap();
+        assert_eq!(got, should_be);
+    }
 }

src/cmd/serve.rs

@@ -161,5 +161,12 @@ async fn serve(
     let fallback_route = warp::fs::file(build_dir.join(file_404))
         .map(|reply| warp::reply::with_status(reply, warp::http::StatusCode::NOT_FOUND));
     let routes = livereload.or(book_route).or(fallback_route);
+
+    std::panic::set_hook(Box::new(move |panic_info| {
+        // exit if serve panics
+        error!("Unable to serve: {}", panic_info);
+        std::process::exit(1);
+    }));
+
     warp::serve(routes).run(address).await;
 }

src/cmd/watch.rs

@@ -58,7 +58,7 @@ pub fn execute(args: &ArgMatches) -> Result<()> {
     Ok(())
 }
 
-fn remove_ignored_files(book_root: &PathBuf, paths: &[PathBuf]) -> Vec<PathBuf> {
+fn remove_ignored_files(book_root: &Path, paths: &[PathBuf]) -> Vec<PathBuf> {
     if paths.is_empty() {
         return vec![];
     }
@@ -81,7 +81,7 @@ fn remove_ignored_files(book_root: &PathBuf, paths: &[PathBuf]) -> Vec<PathBuf>
     }
 }
 
-fn find_gitignore(book_root: &PathBuf) -> Option<PathBuf> {
+fn find_gitignore(book_root: &Path) -> Option<PathBuf> {
     book_root
         .ancestors()
         .map(|p| p.join(".gitignore"))

src/config.rs

@@ -294,6 +294,7 @@ impl Default for Config {
         }
     }
 }
+
 impl<'de> Deserialize<'de> for Config {
     fn deserialize<D: Deserializer<'de>>(de: D) -> std::result::Result<Self, D::Error> {
         let raw = Value::deserialize(de)?;
@@ -310,10 +311,10 @@ impl<'de> Deserialize<'de> for Config {
             return Ok(Config::from_legacy(raw));
         }
 
+        use serde::de::Error;
         let mut table = match raw {
             Value::Table(t) => t,
             _ => {
-                use serde::de::Error;
                 return Err(D::Error::custom(
                     "A config file should always be a toml table",
                 ));
@@ -322,17 +323,20 @@ impl<'de> Deserialize<'de> for Config {
 
         let book: BookConfig = table
             .remove("book")
-            .and_then(|value| value.try_into().ok())
+            .map(|book| book.try_into().map_err(D::Error::custom))
+            .transpose()?
             .unwrap_or_default();
 
         let build: BuildConfig = table
             .remove("build")
-            .and_then(|value| value.try_into().ok())
+            .map(|build| build.try_into().map_err(D::Error::custom))
+            .transpose()?
             .unwrap_or_default();
 
         let rust: RustConfig = table
             .remove("rust")
-            .and_then(|value| value.try_into().ok())
+            .map(|rust| rust.try_into().map_err(D::Error::custom))
+            .transpose()?
             .unwrap_or_default();
 
         Ok(Config {
@@ -522,6 +526,10 @@ pub struct HtmlConfig {
     ///
     /// [custom domain]: https://docs.github.com/en/github/working-with-github-pages/managing-a-custom-domain-for-your-github-pages-site
     pub cname: Option<String>,
+    /// Edit url template, when set shows a "Suggest an edit" button for
+    /// directly jumping to editing the currently viewed page.
+    /// Contains {path} that is replaced with chapter source file path
+    pub edit_url_template: Option<String>,
     /// This is used as a bit of a workaround for the `mdbook serve` command.
     /// Basically, because you set the websocket port from the command line, the
     /// `mdbook serve` command needs a way to let the HTML renderer know where
@@ -554,6 +562,7 @@ impl Default for HtmlConfig {
             search: None,
             git_repository_url: None,
             git_repository_icon: None,
+            edit_url_template: None,
             input_404: None,
             site_url: None,
             cname: None,
@@ -566,7 +575,7 @@ impl Default for HtmlConfig {
 impl HtmlConfig {
     /// Returns the directory of theme from the provided root directory. If the
     /// directory is not present it will append the default directory of "theme"
-    pub fn theme_dir(&self, root: &PathBuf) -> PathBuf {
+    pub fn theme_dir(&self, root: &Path) -> PathBuf {
         match self.theme {
             Some(ref d) => root.join(d),
             None => root.join("theme"),
@@ -651,7 +660,7 @@ pub struct Search {
     pub boost_paragraph: u8,
     /// True if the searchword `micro` should match `microwave`. Default: `true`.
     pub expand: bool,
-    /// Documents are split into smaller parts, seperated by headings. This defines, until which
+    /// Documents are split into smaller parts, separated by headings. This defines, until which
     /// level of heading documents should be split. Default: `3`. (`### This is a level 3 heading`)
     pub heading_split_level: u8,
     /// Copy JavaScript files for the search functionality to the output directory?
@@ -1065,4 +1074,57 @@ mod tests {
         assert_eq!(html_config.input_404, Some("missing.md".to_string()));
         assert_eq!(&get_404_output_file(&html_config.input_404), "missing.html");
     }
+
+    #[test]
+    #[should_panic(expected = "Invalid configuration file")]
+    fn invalid_language_type_error() {
+        let src = r#"
+        [book]
+        title = "mdBook Documentation"
+        language = ["en", "pt-br"]
+        description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+        authors = ["Mathieu David"]
+        src = "./source"
+        "#;
+
+        Config::from_str(src).unwrap();
+    }
+
+    #[test]
+    #[should_panic(expected = "Invalid configuration file")]
+    fn invalid_title_type() {
+        let src = r#"
+        [book]
+        title = 20
+        language = "en"
+        description = "Create book from markdown files. Like Gitbook but implemented in Rust"
+        authors = ["Mathieu David"]
+        src = "./source"
+        "#;
+
+        Config::from_str(src).unwrap();
+    }
+
+    #[test]
+    #[should_panic(expected = "Invalid configuration file")]
+    fn invalid_build_dir_type() {
+        let src = r#"
+        [build]
+        build-dir = 99
+        create-missing = false
+        "#;
+
+        Config::from_str(src).unwrap();
+    }
+
+    #[test]
+    #[should_panic(expected = "Invalid configuration file")]
+    fn invalid_rust_edition() {
+        let src = r#"
+        [rust]
+        edition = "1999"
+        "#;
+
+        Config::from_str(src).unwrap();
+    }
 }

src/preprocess/cmd.rs

@@ -109,18 +109,28 @@ impl Preprocessor for CmdPreprocessor {
 
         self.write_input_to_child(&mut child, &book, ctx);
 
-        let output = child
-            .wait_with_output()
-            .with_context(|| "Error waiting for the preprocessor to complete")?;
+        let output = child.wait_with_output().with_context(|| {
+            format!(
+                "Error waiting for the \"{}\" preprocessor to complete",
+                self.name
+            )
+        })?;
 
         trace!("{} exited with output: {:?}", self.cmd, output);
         ensure!(
             output.status.success(),
-            "The preprocessor exited unsuccessfully"
+            format!(
+                "The \"{}\" preprocessor exited unsuccessfully with {} status",
+                self.name, output.status
+            )
         );
 
-        serde_json::from_slice(&output.stdout)
-            .with_context(|| "Unable to parse the preprocessed book")
+        serde_json::from_slice(&output.stdout).with_context(|| {
+            format!(
+                "Unable to parse the preprocessed book from \"{}\" processor",
+                self.name
+            )
+        })
     }
 
     fn supports_renderer(&self, renderer: &str) -> bool {

src/preprocess/links.rs

@@ -23,6 +23,7 @@ const MAX_LINK_NESTED_DEPTH: usize = 10;
 ///   This hides the lines from initial display but shows them when the reader expands the code
 ///   block and provides them to Rustdoc for testing.
 /// - `{{# playground}}` - Insert runnable Rust files
+/// - `{{# title}}` - Override \<title\> of a webpage.
 #[derive(Default)]
 pub struct LinkPreprocessor;
 
@@ -51,8 +52,15 @@ impl Preprocessor for LinkPreprocessor {
                         .map(|dir| src_dir.join(dir))
                         .expect("All book items have a parent");
 
-                    let content = replace_all(&ch.content, base, chapter_path, 0);
+                    let mut chapter_title = ch.name.clone();
+                    let content =
+                        replace_all(&ch.content, base, chapter_path, 0, &mut chapter_title);
                     ch.content = content;
+                    if chapter_title != ch.name {
+                        ctx.chapter_titles
+                            .borrow_mut()
+                            .insert(chapter_path.clone(), chapter_title);
+                    }
                 }
             }
         });
@@ -61,7 +69,13 @@ impl Preprocessor for LinkPreprocessor {
     }
 }
 
-fn replace_all<P1, P2>(s: &str, path: P1, source: P2, depth: usize) -> String
+fn replace_all<P1, P2>(
+    s: &str,
+    path: P1,
+    source: P2,
+    depth: usize,
+    chapter_title: &mut String,
+) -> String
 where
     P1: AsRef<Path>,
     P2: AsRef<Path>,
@@ -77,11 +91,17 @@ where
     for link in find_links(s) {
         replaced.push_str(&s[previous_end_index..link.start_index]);
 
-        match link.render_with_path(&path) {
+        match link.render_with_path(&path, chapter_title) {
             Ok(new_content) => {
                 if depth < MAX_LINK_NESTED_DEPTH {
                     if let Some(rel_path) = link.link_type.relative_path(path) {
-                        replaced.push_str(&replace_all(&new_content, rel_path, source, depth + 1));
+                        replaced.push_str(&replace_all(
+                            &new_content,
+                            rel_path,
+                            source,
+                            depth + 1,
+                            chapter_title,
+                        ));
                     } else {
                         replaced.push_str(&new_content);
                     }
@@ -116,6 +136,7 @@ enum LinkType<'a> {
     Include(PathBuf, RangeOrAnchor),
     Playground(PathBuf, Vec<&'a str>),
     RustdocInclude(PathBuf, RangeOrAnchor),
+    Title(&'a str),
 }
 
 #[derive(PartialEq, Debug, Clone)]
@@ -185,6 +206,7 @@ impl<'a> LinkType<'a> {
             LinkType::Include(p, _) => Some(return_relative_path(base, &p)),
             LinkType::Playground(p, _) => Some(return_relative_path(base, &p)),
             LinkType::RustdocInclude(p, _) => Some(return_relative_path(base, &p)),
+            LinkType::Title(_) => None,
         }
     }
 }
@@ -255,6 +277,9 @@ struct Link<'a> {
 impl<'a> Link<'a> {
     fn from_capture(cap: Captures<'a>) -> Option<Link<'a>> {
         let link_type = match (cap.get(0), cap.get(1), cap.get(2)) {
+            (_, Some(typ), Some(title)) if typ.as_str() == "title" => {
+                Some(LinkType::Title(title.as_str()))
+            }
             (_, Some(typ), Some(rest)) => {
                 let mut path_props = rest.as_str().split_whitespace();
                 let file_arg = path_props.next();
@@ -291,7 +316,11 @@ impl<'a> Link<'a> {
         })
     }
 
-    fn render_with_path<P: AsRef<Path>>(&self, base: P) -> Result<String> {
+    fn render_with_path<P: AsRef<Path>>(
+        &self,
+        base: P,
+        chapter_title: &mut String,
+    ) -> Result<String> {
         let base = base.as_ref();
         match self.link_type {
             // omit the escape char
@@ -353,6 +382,10 @@ impl<'a> Link<'a> {
                     contents
                 ))
             }
+            LinkType::Title(title) => {
+                *chapter_title = title.to_owned();
+                Ok(String::new())
+            }
         }
     }
 }
@@ -373,17 +406,17 @@ impl<'a> Iterator for LinkIter<'a> {
 
 fn find_links(contents: &str) -> LinkIter<'_> {
     // lazily compute following regex
-    // r"\\\{\{#.*\}\}|\{\{#([a-zA-Z0-9]+)\s*([a-zA-Z0-9_.\-:/\\\s]+)\}\}")?;
+    // r"\\\{\{#.*\}\}|\{\{#([a-zA-Z0-9]+)\s*([^}]+)\}\}")?;
     lazy_static! {
         static ref RE: Regex = Regex::new(
-            r"(?x)                       # insignificant whitespace mode
-            \\\{\{\#.*\}\}               # match escaped link
-            |                            # or
-            \{\{\s*                      # link opening parens and whitespace
-            \#([a-zA-Z0-9_]+)            # link type
-            \s+                          # separating whitespace
-            ([a-zA-Z0-9\s_.\-:/\\\+]+)   # link target path and space separated properties
-            \s*\}\}                      # whitespace and link closing parens"
+            r"(?x)              # insignificant whitespace mode
+            \\\{\{\#.*\}\}      # match escaped link
+            |                   # or
+            \{\{\s*             # link opening parens and whitespace
+            \#([a-zA-Z0-9_]+)   # link type
+            \s+                 # separating whitespace
+            ([^}]+)             # link target path and space separated properties
+            \}\}                # link closing parens"
         )
         .unwrap();
     }
@@ -406,7 +439,21 @@ mod tests {
         ```hbs
         {{#include file.rs}} << an escaped link!
         ```";
-        assert_eq!(replace_all(start, "", "", 0), end);
+        let mut chapter_title = "test_replace_all_escaped".to_owned();
+        assert_eq!(replace_all(start, "", "", 0, &mut chapter_title), end);
+    }
+
+    #[test]
+    fn test_set_chapter_title() {
+        let start = r"{{#title My Title}}
+        # My Chapter
+        ";
+        let end = r"
+        # My Chapter
+        ";
+        let mut chapter_title = "test_set_chapter_title".to_owned();
+        assert_eq!(replace_all(start, "", "", 0, &mut chapter_title), end);
+        assert_eq!(chapter_title, "My Title");
     }
 
     #[test]

src/preprocess/mod.rs

@@ -12,6 +12,8 @@ use crate::book::Book;
 use crate::config::Config;
 use crate::errors::*;
 
+use std::cell::RefCell;
+use std::collections::HashMap;
 use std::path::PathBuf;
 
 /// Extra information for a `Preprocessor` to give them more context when
@@ -27,6 +29,8 @@ pub struct PreprocessorContext {
     /// The calling `mdbook` version.
     pub mdbook_version: String,
     #[serde(skip)]
+    pub(crate) chapter_titles: RefCell<HashMap<PathBuf, String>>,
+    #[serde(skip)]
     __non_exhaustive: (),
 }
 
@@ -38,6 +42,7 @@ impl PreprocessorContext {
             config,
             renderer,
             mdbook_version: crate::MDBOOK_VERSION.to_string(),
+            chapter_titles: RefCell::new(HashMap::new()),
             __non_exhaustive: (),
         }
     }

src/renderer/html_handlebars/hbs_renderer.rs

@@ -1,5 +1,5 @@
 use crate::book::{Book, BookItem};
-use crate::config::{Config, HtmlConfig, Playground, RustEdition};
+use crate::config::{BookConfig, Config, HtmlConfig, Playground, RustEdition};
 use crate::errors::*;
 use crate::renderer::html_handlebars::helpers;
 use crate::renderer::{RenderContext, Renderer};
@@ -37,6 +37,20 @@ impl HtmlHandlebars {
             _ => return Ok(()),
         };
 
+        if let Some(ref edit_url_template) = ctx.html_config.edit_url_template {
+            let full_path = ctx.book_config.src.to_str().unwrap_or_default().to_owned()
+                + "/"
+                + ch.source_path
+                    .clone()
+                    .unwrap_or_default()
+                    .to_str()
+                    .unwrap_or_default();
+
+            let edit_url = edit_url_template.replace("{path}", &full_path);
+            ctx.data
+                .insert("git_repository_edit_url".to_owned(), json!(edit_url));
+        }
+
         let content = ch.content.clone();
         let content = utils::render_markdown(&content, ctx.html_config.curly_quotes);
 
@@ -45,6 +59,12 @@ impl HtmlHandlebars {
             ctx.html_config.curly_quotes,
             Some(&path),
         );
+        if !ctx.is_index {
+            // Add page break between chapters
+            // See https://developer.mozilla.org/en-US/docs/Web/CSS/break-before and https://developer.mozilla.org/en-US/docs/Web/CSS/page-break-before
+            // Add both two CSS properties because of the compatibility issue
+            print_content.push_str(r#"<div id="chapter_begin" style="break-before: page; page-break-before: always;"></div>"#);
+        }
         print_content.push_str(&fixed_content);
 
         // Update the context with data for this file
@@ -64,9 +84,12 @@ impl HtmlHandlebars {
             .and_then(serde_json::Value::as_str)
             .unwrap_or("");
 
-        let title = match book_title {
-            "" => ch.name.clone(),
-            _ => ch.name.clone() + " - " + book_title,
+        let title = if let Some(title) = ctx.chapter_titles.get(path) {
+            title.clone()
+        } else if book_title.is_empty() {
+            ch.name.clone()
+        } else {
+            ch.name.clone() + " - " + book_title
         };
 
         ctx.data.insert("path".to_owned(), json!(path));
@@ -110,7 +133,7 @@ impl HtmlHandlebars {
         &self,
         ctx: &RenderContext,
         html_config: &HtmlConfig,
-        src_dir: &PathBuf,
+        src_dir: &Path,
         handlebars: &mut Handlebars<'_>,
         data: &mut serde_json::Map<String, serde_json::Value>,
     ) -> Result<()> {
@@ -437,6 +460,7 @@ impl Renderer for HtmlHandlebars {
     }
 
     fn render(&self, ctx: &RenderContext) -> Result<()> {
+        let book_config = &ctx.config.book;
         let html_config = ctx.config.html_config().unwrap_or_default();
         let src_dir = ctx.root.join(&ctx.config.book.src);
         let destination = &ctx.destination;
@@ -499,8 +523,10 @@ impl Renderer for HtmlHandlebars {
                 destination: destination.to_path_buf(),
                 data: data.clone(),
                 is_index,
+                book_config: book_config.clone(),
                 html_config: html_config.clone(),
                 edition: ctx.config.rust.edition,
+                chapter_titles: &ctx.chapter_titles,
             };
             self.render_item(item, ctx, &mut print_content)?;
             is_index = false;
@@ -914,8 +940,10 @@ struct RenderItemContext<'a> {
     destination: PathBuf,
     data: serde_json::Map<String, serde_json::Value>,
     is_index: bool,
+    book_config: BookConfig,
     html_config: HtmlConfig,
     edition: Option<RustEdition>,
+    chapter_titles: &'a HashMap<PathBuf, String>,
 }
 
 #[cfg(test)]

src/renderer/html_handlebars/search.rs

@@ -141,7 +141,7 @@ fn render_item(
                 body.push_str(&clean_html(&html_block));
             }
             Event::Start(_) | Event::End(_) | Event::Rule | Event::SoftBreak | Event::HardBreak => {
-                // Insert spaces where HTML output would usually seperate text
+                // Insert spaces where HTML output would usually separate text
                 // to ensure words don't get merged together
                 if in_heading {
                     heading.push(' ');

src/renderer/mod.rs

@@ -18,6 +18,7 @@ mod html_handlebars;
 mod markdown_renderer;
 
 use shlex::Shlex;
+use std::collections::HashMap;
 use std::fs;
 use std::io::{self, ErrorKind, Read};
 use std::path::{Path, PathBuf};
@@ -64,6 +65,8 @@ pub struct RenderContext {
     /// guaranteed to be empty or even exist.
     pub destination: PathBuf,
     #[serde(skip)]
+    pub(crate) chapter_titles: HashMap<PathBuf, String>,
+    #[serde(skip)]
     __non_exhaustive: (),
 }
 
@@ -80,6 +83,7 @@ impl RenderContext {
             version: crate::MDBOOK_VERSION.to_string(),
             root: root.into(),
             destination: destination.into(),
+            chapter_titles: HashMap::new(),
             __non_exhaustive: (),
         }
     }
@@ -162,7 +166,7 @@ impl CmdRenderer {
                 } else {
                     // Let this bubble through to later be handled by
                     // handle_render_command_error.
-                    abs_exe.to_path_buf()
+                    abs_exe
                 }
             }
         };

src/theme/css/general.css

@@ -92,7 +92,7 @@ h6:target::before {
 .content ul { line-height: 1.45em; }
 .content a { text-decoration: none; }
 .content a:hover { text-decoration: underline; }
-.content img { max-width: 100%; }
+.content img, .content video { max-width: 100%; }
 .content .header:link,
 .content .header:visited {
     color: var(--fg);

src/theme/index.hbs

@@ -148,13 +148,19 @@
                             <i id="git-repository-button" class="fa {{git_repository_icon}}"></i>
                         </a>
                         {{/if}}
+                        {{#if git_repository_edit_url}}
+                        <a href="{{git_repository_edit_url}}" title="Suggest an edit" aria-label="Suggest an edit">
+                            <i id="git-edit-button" class="fa fa-edit"></i>
+                        </a>
+                        {{/if}}
+
                     </div>
                 </div>
 
                 {{#if search_enabled}}
                 <div id="search-wrapper" class="hidden">
                     <form id="searchbar-outer" class="searchbar-outer">
-                        <input type="search" name="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
+                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                     </form>
                     <div id="searchresults-outer" class="searchresults-outer hidden">
                         <div id="searchresults-header" class="searchresults-header"></div>

src/utils/fs.rs

@@ -4,7 +4,7 @@ use std::fs::{self, File};
 use std::io::Write;
 use std::path::{Component, Path, PathBuf};
 
-/// Naively replaces any path seperator with a forward-slash '/'
+/// Naively replaces any path separator with a forward-slash '/'
 pub fn normalize_path(path: &str) -> String {
     use std::path::is_separator;
     path.chars()

tests/rendered_output.rs

@@ -541,6 +541,57 @@ fn redirects_are_emitted_correctly() {
     }
 }
 
+#[test]
+fn edit_url_has_default_src_dir_edit_url() {
+    let temp = DummyBook::new().build().unwrap();
+    let book_toml = r#"
+        [book]
+        title = "implicit"
+
+        [output.html]
+        edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"    
+        "#;
+
+    write_file(&temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
+
+    let md = MDBook::load(temp.path()).unwrap();
+    md.build().unwrap();
+
+    let index_html = temp.path().join("book").join("index.html");
+    assert_contains_strings(
+        index_html,
+        &vec![
+            r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src/README.md" title="Suggest an edit""#,
+        ],
+    );
+}
+
+#[test]
+fn edit_url_has_configured_src_dir_edit_url() {
+    let temp = DummyBook::new().build().unwrap();
+    let book_toml = r#"
+        [book]
+        title = "implicit"
+        src = "src2"
+
+        [output.html]
+        edit-url-template = "https://github.com/rust-lang/mdBook/edit/master/guide/{path}"    
+        "#;
+
+    write_file(&temp.path(), "book.toml", book_toml.as_bytes()).unwrap();
+
+    let md = MDBook::load(temp.path()).unwrap();
+    md.build().unwrap();
+
+    let index_html = temp.path().join("book").join("index.html");
+    assert_contains_strings(
+        index_html,
+        &vec![
+            r#"href="https://github.com/rust-lang/mdBook/edit/master/guide/src2/README.md" title="Suggest an edit""#,
+        ],
+    );
+}
+
 fn remove_absolute_components(path: &Path) -> impl Iterator<Item = Component> + '_ {
     path.components().skip_while(|c| match c {
         Component::Prefix(_) | Component::RootDir => true,