The jQuery's event handling goes far beyond the simple attaching events to HTML elements and allows us to attach events to JavaScript objects. In fact, the $() wrapper works also on objects, thus providing a quick and simple access to object's properties and methods when combined with the bind() method. Let's see the details.
We have the following JavaScript object:
var Class = {
property: 'Test',
getProperty: function() {
return this.property;
},
setProperty: function(value) {
this.property = value;
}
};
We can attach an event named change to get notified when an object's property changes its value:
$(Class).bind('change', function() {
if(this.property !== 'Test') {
alert('Property changed');
} else {
alert(this.property);
}
});
We can use this event with a jQuery's trigger method. Example:
$(Class).triggerHandler('change'); // 'Test'
Class.setProperty('Foo');
$(Class).triggerHandler('change'); // 'Property changed'
The ideal use for this feature is the Observer Pattern.