Here’s a jQuery plugin I wrote that’ll add HTML5 <mark> tags around keywords or phrases in an element’s body text.

What is mark?

a run of text in one document marked or highlighted for reference purposes, due to its relevance in another context

http://www.whatwg.org/specs/web-apps/

Usage

Add the script to your page, and then when the DOM is ready, do something like:

    $('body').mark('Lorem ipsum');

The plugin can actually be used to wrap any tag around keywords. Simply pass the tag name you want to use as an option:

    $('body').mark({
      text: 'Lorem ipsum',
      tag:  'span',
      cssClass:  'mark'
    });

The above example will wrap span elements around the words lorem and ipsum. Each span element will have the class ‘mark’. View an example implementation.

TODO

1. Input sanitation on the text to be marked. Currently the text is dumped straight into a regular expression. It needs to be escaped so that any regular expression meta-characters are interpreted as literals.
2. Similarly, HTML special characters in the input need to be expanded into their HTML entities.
3. From what I can see, IE doesn’t like <mark> tags, and seems to automatically self close the opening and closing tags inserted into the DOM. WTF? Can anyone shed any light on this problem? For now, you’re going to have to use a <span> with a CSS class

If you’re interested in contributing, get in touch