jekyll-katex

This is a Jekyll plugin for performing compile-time math rendering via the KaTeX library. KaTeX is a library for rending math on the web using LaTeX, similar to MathJax.

KaTeX differs from MathJax in that it displays faster rendering speed and renders to pure HTML rather than PNGs. There are various resources in benchmarking and comparing their performance, for more info, start here.

Comes packaged with KaTeX 0.11.1 but you can specify a different version in your Jekyll _config.yml (see below).

Installation

In your Jekyll project, add the plugin to your _config.yml, e.g.:
```
plugins:
  - jekyll-katex
```
Add jekyll-katex to your gems.rb/Gemfile plugin block:
```
group :jekyll_plugins do
  gem 'jekyll-katex'
end
```
Once done, execute bundle install.
Add KaTeX CSS and Fonts. Follow the installation instructions on the KaTeX README. You can skip including the .js file unless you want to do client-side in-browser rendering, as well.

Put the following (adjusting for your version) in your page headers:
```
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css" integrity="sha384-zB1R0rpPzHqg7Kpt0Aljp8JPLqbXI3bhnPWROx27a9N0Ll6ZP/+DiW/UqRcLbRjq" crossorigin="anonymous">
```

Configuration

Supported configuration values, shown with default values:

katex:
  js_path: "{{ Gem::lib_path }}/assets/js"  # Path used to search for katex.min.js
  rendering_options:
    # Default KaTeX rendering options. See https://github.com/Khan/KaTeX#rendering-options
    throw_error: true                       # throwOnError - set to false if you want rendering to output error as text rather than a build error
    error_color: "#cc0000"                  # errorColor

Usage

There are two liquid tags: katex and katexmm.

katex

Use the katex liquid tag for LaTeX math equations like so:

{% katex %}
c = \pm\sqrt{a^2 + b^2}
{% endkatex %}

If you want the equation to be rendered in display mode (on its own line, centered, large symbols), just pass in the display parameter:

{% katex display %}
c = \pm\sqrt{a^2 + b^2}
{% endkatex %}

katexmm

The katex liquid tag can be cumbersome, particularly if you have many inline blocks, which would need to be opened and closed repeatedly, cluttering the source text. katexmm is an alternative that supports fenced math mode blocks similar to standard latex:

{% katexmm %}
This is a mixed environment where you can have normal text and $c = \pm\sqrt{a^2 + b^2}$ fenced math. \$!
{% endkatexmm %}

$ for inline
$$ for display mode
\$ to escape $ anywhere within the katexmm environment

Development

$ bundle install
$ rake build

Contributing

Feel free to open issues and pull requests.

License

The gem is available as open source under the terms of the MIT License.

linjer / jekyll-katex