Documentation
Plugins/livequery
From jQuery JavaScript Library
Contents |
Overview
Live Query utilizes the power of jQuery selectors by binding events or firing callbacks for matched elements auto-magically, even after the page has been loaded and the DOM updated.
For example you could use the following code to bind a click event to all A tags, even any A tags you might add via AJAX.
$('a')
.livequery('click', function(event) {
alert('clicked');
return false;
});
Once you add new A tags to your document, Live Query will bind the click event and there is nothing else that needs to be called or done.
When an element no longer matches a selector the events Live Query bound to it are unbound. The Live Query can be expired which will no longer bind anymore events and unbind all the events it previously bound.
Live Query can even be used with the more powerful jQuery selectors. The following Live Query will match and bind a click event to all A tags that have a rel attribute with the word "friend" in it. If one of the A tags is modified by removing the word "friend" from the rel attribute, the click event will be unbound since it is no longer matched by the Live Query.
$('a[rel*=friend]')
.livequery('click', function(event) {
doSomething();
});
Live Query also has the ability to fire a function (callback) when it matches a new element and another function (callback) for when an element is no longer matched. This provides ultimate flexibility and untold use-cases. For example the following code uses a function based Live Query to implement the jQuery hover helper method and remove it when the element is no longer matched.
$('li')
.livequery(function(){
// use the helper function hover to bind a mouseover and mouseout event
$(this)
.hover(function() {
$(this).addClass('hover');
}, function() {
$(this).removeClass('hover');
});
}, function() {
// unbind the mouseover and mouseout events
$(this)
.unbind('mouseover')
.unbind('mouseout');
});
Three Flavors
Live Query comes in three flavors: full (with comments), minified and packed. I recommend using the minified version along with HTTP Compression for production.
Browser Support
Live Query is tested in those browsers that jQuery supports. See browser compatibility for more info.
Depends On
Live Query depends on jQuery 1.1.3+.
License
Live Query is Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses. Copyright © 2007 Brandon Aaron (http://brandonaaron.net/).
API Documentation
For Plugin Developers
If your plugin modifies the DOM without using the built-in DOM Modification methods (append, addClass, etc), you can register your plugin with Live Query like this.
if (jQuery.livequery)
jQuery.livequery.registerPlugin("pluginMethodName");
You can register several plugin methods at once by just passing them as additional arguments to the registerPlugin method.
if (jQuery.livequery)
jQuery.livequery.registerPlugin("method1", "method2", "method3");
Download
The latest release can be downloaded from the Live Query project page.
Or you can live on the edge and just pull from SVN: http://jqueryjs.googlecode.com/svn/trunk/plugins/livequery/
Support
Please report bugs, features, patches or requests for support via the Live Query project page.