The `[output.html.print]` table provides options for controlling the printable output.
By default, mdBook will include an icon on the top right of the book (which looks like <iclass="fa fa-print"></i>) that will print the book as a single page.
```toml
[output.html.print]
enable = true # include support for printable output
page-break = true # insert page-break after each chapter
```
- **enable:** Enable print support. When `false`, all print support will not be
rendered. Defaults to `true`.
- **page-break:** Insert page breaks between chapters. Defaults to `true`.
### `[output.html.fold]`
The `[output.html.fold]` table provides options for controlling folding of the chapter listing in the navigation sidebar.
```toml
[output.html.fold]
enable = false # whether or not to enable section folding
level = 0 # the depth to start folding
```
- **enable:** Enable section-folding. When off, all folds are open.
Defaults to `false`.
- **level:** The higher the more folded regions are open. When level is 0, all
folds are closed. Defaults to `0`.
### `[output.html.playground]`
The `[output.html.playground]` table provides options for controlling Rust sample code blocks, and their integration with the [Rust Playground].
[Rust Playground]: https://play.rust-lang.org/
```toml
[output.html.playground]
editable = false # allows editing the source code
copyable = true # include the copy button for copying code snippets
copy-js = true # includes the JavaScript for the code editor
line-numbers = false # displays line numbers for editable code
runnable = true # displays a run button for rust code
```
- **editable:** Allow editing the source code. Defaults to `false`.
- **copyable:** Display the copy button on code snippets. Defaults to `true`.
- **copy-js:** Copy JavaScript files for the editor to the output directory.
Defaults to `true`.
- **line-numbers:** Display line numbers on editable sections of code. Requires both `editable` and `copy-js` to be `true`. Defaults to `false`.
- **runnable:** Displays a run button for rust code snippets. Changing this to `false` will disable the run in playground feature globally. Defaults to `true`.
[Ace]: https://ace.c9.io/
### `[output.html.code]`
The `[output.html.code]` table provides options for controlling code blocks.
```toml
[output.html.code]
# A prefix string per language (one or more chars).
# Any line starting with whitespace+prefix is hidden.
hidelines = { python = "~" }
```
- **hidelines:** A table that defines how [hidden code lines](../mdbook.md#hiding-code-lines) work for each language.
The key is the language and the value is a string that will cause code lines starting with that prefix to be hidden.
### `[output.html.search]`
The `[output.html.search]` table provides options for controlling the built-in text [search].
mdBook must be compiled with the `search` feature enabled (on by default).
[search]: ../../guide/reading.md#search
```toml
[output.html.search]
enable = true # enables the search feature
limit-results = 30 # maximum number of search results
teaser-word-count = 30 # number of words used for a search result teaser
use-boolean-and = true # multiple search terms must all match
boost-title = 2 # ranking boost factor for matches in headers
boost-hierarchy = 1 # ranking boost factor for matches in page names
boost-paragraph = 1 # ranking boost factor for matches in text
expand = true # partial words will match longer terms
heading-split-level = 3 # link results to heading levels
copy-js = true # include Javascript code for search
```
- **enable:** Enables the search feature. Defaults to `true`.
- **limit-results:** The maximum number of search results. Defaults to `30`.
- **teaser-word-count:** The number of words used for a search result teaser.
Defaults to `30`.
- **use-boolean-and:** Define the logical link between multiple search words. If
true, all search words must appear in each result. Defaults to `false`.
- **boost-title:** Boost factor for the search result score if a search word
appears in the header. Defaults to `2`.
- **boost-hierarchy:** Boost factor for the search result score if a search word
appears in the hierarchy. The hierarchy contains all titles of the parent
documents and all parent headings. Defaults to `1`.
- **boost-paragraph:** Boost factor for the search result score if a search word
appears in the text. Defaults to `1`.
- **expand:** True if search should match longer results e.g. search `micro`
should match `microwave`. Defaults to `true`.
- **heading-split-level:** Search results will link to a section of the document
which contains the result. Documents are split into sections by headings this
level or less. Defaults to `3`. (`### This is a level 3 heading`)
- **copy-js:** Copy JavaScript files for the search implementation to the output
directory. Defaults to `true`.
### `[output.html.redirect]`
The `[output.html.redirect]` table provides a way to add redirects.
This is useful when you move, rename, or remove a page to ensure that links to the old URL will go to the new location.
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`).
This will generate an HTML page which will automatically redirect to the given location.
Note that the source location does not support `#` anchor redirects.
## Markdown Renderer
The Markdown renderer will run preprocessors and then output the resulting
Markdown. This is mostly useful for debugging preprocessors, especially in
conjunction with `mdbook test` to see the Markdown that `mdbook` is passing
to `rustdoc`.
The Markdown renderer is included with `mdbook` but disabled by default.
Enable it by adding an empty table to your `book.toml` as follows:
```toml
[output.markdown]
```
There are no configuration options for the Markdown renderer at this time;
only whether it is enabled or disabled.
See [the preprocessors documentation](preprocessors.md) for how to
specify which preprocessors should run before the Markdown renderer.
