Jekyll-Quicklatex

Jekyll-Quicklatex is a converter plugin for Jekyll. It convert latex code snippet to picture embeded in your page.

Installation

Add this line to your application's Gemfile:

gem 'jekyll-quicklatex'

And then execute:

$ bundle

Or install it yourself as:

$ gem install jekyll-quicklatex

Usage

for example, we use package tikz to describe a picture

{% latex %}
{% highlight latex %}
\usepackage{tikz}
\begin{tikzpicture}[scale=3]
  \tikzset{Karl's grid/.style ={help lines,color=#1!50},
    Karl's grid/.default=blue}

  \clip (-0.1,-0.2) rectangle (1.1,1.51);

  \draw[step=.5cm,Karl's grid] (-1.4,-1.4) grid (1.4,1.4);
  \draw[->] (-1.5,0) -- (1.5,0);
  \draw[->] (0, -1.5) -- (0,1.5);
  \draw (0,0) circle [radius=1cm];
  \shadedraw[left color=gray, right color=green, draw=green!50!black] (0,0) -- (3mm,0mm)
    arc [start angle=0, end angle=30, radius=3mm] -- cycle;

  \draw[red,very thick] (30:1cm) -- +(0,-0.5);
  \draw[blue,very thick] (30:1cm) ++(0,-0.5) -- (0,0);
  \draw[orange,very thick] (1,0) -- (1, {tan(30)});

  \foreach \x in {-1cm,-0.5cm,1cm}
  \draw (\x,-1pt) -- (\x,1pt);
  \foreach \y in {-1cm,-0.5cm,0.5cm,1cm}
  \draw (-1pt,\y) -- (1pt,\y);
\end{tikzpicture}
{% endhighlight %}
{% endlatex %}

it'll render the img and show its source below!

see result here: learn tikz by examples

Strategy

This plugin visit quicklatex to compile code snippet into picture, then fetch the picture back into ./assets/latex directory, and render a <img> on your page.

At the same time, it'll write new file named latex.cache to avoid recompile the snippet again. If you want to recompile all the snippets, delete latex.cache first.

WARNING BELOW

The process of fetching picture back is after copy assets into _site directory when jekyll build. So after first build, pictures are fetched but not in _site/. If you build again, everything's fine. That's the way I recommend.

In this plugin, I use the stratery that adding a fallback quicklatex link for every <img> links. If local picture is not found, it'll fetch remote picture automatically. Pay attention, link in quicklatex has a expire time, so don't rely on this stratery.

Development

After checking out the repo, run bundle install to install dependencies. Then, run rake to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

License

MIT