mdbook-katex
is a preprocessor for mdBook, pre-rendering LaTex equations to HTML at build time. It allows for very fast page loading, compared to rendering equations in the browser.
This preprocessor uses the katex crate; see this page for the list of supported LaTex functions.
Getting Started
First, install mdbook-katex
cargo install mdbook-katex
Then, add the following lines to your book.toml
file
[]
[]
You can now use $
and $$
delimiters for inline and display equations within your .md
files. If you need a regular dollar symbol, you can escape delimiters with a backslash \$
.
# Chapter 1
Here is an inline example, $ \pi(\theta) $,
an equation,
$$ \nabla f(x) \in \mathbb{R}^n, $$
and a regular \$ symbol.
LaTex equations will be rendered as HTML when running mdbook build
or mdbook serve
as usual.
Katex options
The preprocessor supports passing options to the katex-rs crate in order
to configure its behaviour. These options are specified under the
[preprocessor.katex]
directive.
The currently spported arguments are:
Argument | Type |
---|---|
leqno |
boolean |
fleqn |
boolean |
throw-on-error |
boolean |
error-color |
string |
min-rule-thickness |
number |
max-size |
number |
max-expand |
number |
trust |
boolean |
There are also options to configure the behaviour of the preprocessor:
Option | Default | Description |
---|---|---|
static-css |
false |
Generates fully static html pages with katex styling |
macros |
None |
Path to macros file (see Custom macros) |
include-src |
false |
Append the source code for the rendered math expressions after them |
For example:
[]
= false
= false
Custom macros
Custom LaTex macros must be defined in a .txt
file, according to the following pattern
\grad:{\nabla}
\R:{\mathbb{R}^{#1 \times #2}}
You need to specify the path of this file in your book.toml
as follows
[]
= "path/to/macros.txt"
These macros can then be used in your .md
files
# Chapter 1
$$ \grad f(x) \in \R{n}{p} $$
Including math source
This option is added so users can have a convenient way to copy the source code of math expressions when they view the book.
When include-src
is set to true
, the included math source code is appended to each rendered math expression.
Math expressions are span
elements with class="katex
.
Appended math source code is wrapped in span
elements with class="katex-src"
.
For example,
Define $f(x)$:
$$
f(x)=x^2\\
x\in\R
$$
is rendered as (the content of the katex
span
s are omitted and represented as …
)
Define … f(x) :
… f(x)=x^2\\\\ x\\in\\R
The math source code is included in a minimal fashion, and it is up to the users to write custom CSS and JavaScript to make use of it.
For more information about adding custom CSS and JavaScript in mdbook
, see additional-css and additional-js.
If you need more information about this feature, please check the issues or file a new issue.
Caveats
The build artifact of the book will be in a folder named html
inside the directory you specify instead of being directly there.
Consider this when you use mdbook_katex
in your CIs.
$\backslash$
does not work, but you can use $\setminus$
instead.