Hacking at 0300

One thing that is nice about Prism is that it provides hooks to extend the syntax highlighting, so it is straightforward to create a plugin that adds features like my line numbering, so I can do things like:

<pre><code class="language-javascript" data-linenumber=4>
function foo(arg){
  console.log('You said: '+arg);
}</code></pre>

Download the code.

Download the CSS (the linenumbering parts are at the bottom).

See an example (working together with the line highlighting plugin)(note that Chrome requires an explicit line-height on the <pre> to work).

You use the plugin simply by including the script after loading Prism, then adding the data-linenumber attribute to the code element, as in <code class="language-javascript" data-linenumber><code>. The default first line is 0 (we're computer scientists after all!). Change it by assigning a value to the data-linenumber attribute, as in <code class="language-javascript" data-linenumber=4><code>.

As I discussed before, the code element must have a style of counter-reset: something and each line is wrapped in a <span class="line"> element, and those must have a style of counter-increment: something. Then the span.line:before selector needs a style of content: counter(something).

Hope this helps someone!