Sunday, November 9, 2008

Using .attr for ARIA in jQuery UI

Last week I found some time to hack on jQuery UI again. After talking to Scott we decided to pull the ariaRole, and ariaState API out of UI core, and put the browser normalization for ARIA right into the popular attr function where it belongs.

At this time, jQuery UI is a dependency for this enhanced attr function. We add the ARIA smarts in ui.core.js via proxy function, like this:
// proxy attr
var attr = $.attr;
$.attr = function () {
// if aria usage then normalize
// else
attr.apply(arguments);
};
See the patch for the real deal. You might notice that we actually only proxy if a naughty browser/version is sniffed. Let's hope this ARIA normalization business won't grow too big and complex when the other browser ARIA implementations roll out. If we can keep it small and tight the attr enhancement really belongs in jQuery core. Or maybe it belongs there regardless? If you are doing Web2.0 development you're probably going to need it.

Here's an example of how one might use chaining to add the ARIA role of "tab" to all elements with a class "ui-accordion-header), and the ARIA state "aria-expanded=false", and add the ARIA role "tabpanel" to the next sibling of each (which happens to be the panels).
$(".ui-accordion-header")
.attr('role','tab')
.attr('aria-expanded','false')
.next()
.attr('role','tabpanel');
Working with Scott González and others on jQuery has been a very meaningful aspect of my Mozilla Foundation grant. Thanks Mozilla.

Thanks for reading.

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