Class glow.events.Target

Defined in: core.js.

Class Summary
Constructor Attributes	Constructor Name and Description
	glow.events.Target() An object that can have event listeners and fire events.

Method Summary
Method Attributes	Method Name and Description
	detach(eventName, callback, thisVal) Remove an event listener.
<static>	glow.events.Target.extend(obj) Convenience method to add Target instance methods onto an object.
	fire(eventName, event) Fire an event.
	on(eventName, callback, thisVal) Listen for an event

Class Detail

glow.events.Target()

An object that can have event listeners and fire events. Extend this class to make your own objects have 'on' and 'fire' methods.

		// Ball is our constructor
		function Ball() {
			// ...
		}
		       
		// make Ball inherit from Target
		glow.util.extend(Ball, glow.events.Target, {
			// additional methods for Ball here, eg:
			bowl: function() {
				// ...
			}
		});
		       
		// now instances of Ball can receive event listeners
		var myBall = new Ball();
		myBall.on('bounce', function() {
			alert('BOING!');
		});
		       
		// and events can be fired from Ball instances
		myBall.fire('bounce');

Method Detail

detach(eventName, callback, thisVal)

Remove an event listener.

		function showListener() {
		    // ...
		}
		       
		// add listener
		myObj.on('show', showListener);
		       
		// remove listener
		myObj.detach('show', showListener);

		// note the following WILL NOT WORK
		       
		// add listener
		myObj.on('show', function() {
		    alert('hi');
		});
		       
		// remove listener
		myObj.detach('show', function() {
			alert('hi');
		});
		       
		// this is because both callbacks are different function instances

Parameters:
{string} eventName: Name of the event to remove.
{function} callback: Callback to detach.
{Object} thisVal Optional: Value of 'this' within the callback. By default, this is the object being listened to.

Returns:: this Target object

<static> glow.events.Target.extend(obj)

Convenience method to add Target instance methods onto an object. If you want to add Target methods to a class, extend glow.events.Target instead.

		var myApplication = {};
		       
		glow.events.Target.extend(myApplication);
		       
		// now myApplication can fire events...
		myApplication.fire('load');
		       
		// and other objects can listen for those events
		myApplication.on('load', function(e) {
			alert('App loaded');
		});

Parameters:
{Object} obj: Object to add Target instance methods to.

fire(eventName, event)

Fire an event.

		myObj.fire('show');

		// adding properties to the event object
		myBall.fire('bounce', {
		    velocity: 30
		});

		// BallBounceEvent extends glow.events.Event but has extra methods
		myBall.fire( 'bounce', new BallBounceEvent(myBall) );

Parameters:
{string} eventName: Name of the event to fire.
{glow.events.Event|Object} event Optional: Event object to pass into listeners. You can provide a simple object of key-value pairs which will be added as properties of a glow.events.Event instance.

Returns:: glow.events.Event

on(eventName, callback, thisVal)

Listen for an event

		myObj.on('show', function() {
		    // do stuff
		});

Parameters:
{string} eventName: Name of the event to listen for.
{function} callback: Function to call when the event fires. The callback is passed a single event object. The type of this object depends on the event (see documentation for the event you're listening to).
{Object} thisVal Optional: Value of 'this' within the callback. By default, this is the object being listened to.

Returns:: this

Classes

Class glow.events.Target