highlight.js: description

Installation and usage

Downloaded package includes file "highlight.pack.js" which is a full compressed version of the library intended to use in production. All uncompressed source files are also available, feel free to look into them!

Put in your page a link to the library, a link to a stylesheet and call the initialization function:

<link rel="stylesheet" href="styles/default.css">
<script src="highlight.pack.js"></script>
<script>hljs.initHighlightingOnLoad();</script>

Here you're basically done. Upon loading the page the script looks in for fragments <pre><code>...</code></pre> that are traditionally used to mark up code examples and wraps syntax units into <span>s that are styled by CSS.

Look further for other options on initialization, styling and using highlight.js with Javascript frameworks.

TAB replacement

You can replaces TAB ('\x09') characters used for indentation in your code with some fixed number of spaces or with a <span> to set them special styling:

<script>
  hljs.tabReplace = '    '; // 4 spaces
  // ... or hljs.tabReplace = '<span class="indent">\t</span>';

  hljs.initHighlightingOnLoad();
</script>

Custom initialization

If you use different markup for code blocks you can initialize them manually with highlightBlock(code, tabReplace) function. It takes a DOM element containing the code to highlight and optionally a string with which to replace TAB characters.

Initialization using for example jQuery might look like this:

$(document).ready(function() {
  $('pre code').each(function(i, e) {hljs.highlightBlock(e, '    ')});
});

If your code container relies on <br> tags instead of line breaks (i.e. if it's not <pre>) pass true into third parameter of highlightBlock:

$('div.code').each(function(i, e) {hljs.highlightBlock(e, null, true)});

Styling

Elements of code marked up with classes can be styled as desired:

.comment {
  color: gray;
}

.keyword {
  font-weight: bold;
}

.python .string {
  color: blue;
}

.html .atribute .value {
  color: green;
}

Highligt.js comes with several style themes located in "styles" directory that can be used directly or as a base for your own experiments.

For full reference list of classes see classref.txt.

Export

File export.html contains a little program that shows and allows to copy and paste an HTML code generated by the highlighter for any code snippet. This can be useful in situations when one can't use the script itself on a site.

Heuristics

Autodetection of a code's language is done with a simple heuristics: the program tries to highlight a fragment with all available languages and counts all syntactic structures that it finds along the way. The language with greatest count wins.

This means that in short fragments the probability of an error is high (and it really happens sometimes). In this cases you can set the fragment's language explicitly by assigning a class to the <code> element:

<pre><code class="html">...</code></pre>

You can use class names recommended in HTML5: "language-html", "language-php". Classes also can be assigned to the <pre> element.

To disable highlighting of a fragment altogether use "no-highlight" class:

<pre><code class="no-highlight">...</code></pre>