AsBroadcaster

Object   |   +-AsBroadcaster public class AsBroadcaster extends Object

Note

A common mistake is to capitalize the second letter of AsBroadcaster. When calling the AsBroadcaster.initialize() method, ensure that the second letter is lowercase. Any misspelling of AsBroadcaster fails silently.

Availability: ActionScript 1.0; Flash Player 6

Property summary

Modifiers	Property	Description
	_listeners:Array [read-only]	A list of references to all registered listener objects.

Properties inherited from class Object

constructor (Object.constructor property),  __proto__ (Object.__proto__ property), prototype (Object.prototype property),  __resolve (Object.__resolve property)

Method summary

Modifiers	Signature	Description
	addListener(listenerObj:Object) : Boolean	Registers an object to receive event notification messages.
	broadcastMessage(eventName:String) : Void	Sends an event message to each object in the list of listeners.
static	initialize(obj:Object) : Void	Adds event notification and listener management functionality to a given object.
	removeListener(listenerObj:Object) : Boolean	Removes an object from the list of objects that receive event notification messages.

Methods inherited from class Object

addProperty (Object.addProperty method),  hasOwnProperty (Object.hasOwnProperty method), isPropertyEnumerable (Object.isPropertyEnumerable method),  isPrototypeOf (Object.isPrototypeOf method), registerClass (Object.registerClass  method), toString (Object.toString method), unwatch (Object.unwatch  method), valueOf (Object.valueOf method), watch (Object.watch method)

addListener (AsBroadcaster.addListener method)

public addListener(listenerObj:Object) : Boolean

Registers an object to receive event notification messages. This method is called on the broadcasting object and the listener object is sent as an argument.

Availability: ActionScript 1.0; Flash Player 6

Parameters

listenerObj:Object - The name of the listener object that receives event notification.

Returns

Boolean - Although this method technically returns a Boolean value, in practical terms it returns Void because it always returns the value TRue.

Example

The following example is an excerpt from the full example provided in the entry for the AsBroadcaster.initialize() method.

someObject.addListener(myListener1); // Register myListener1 as listener. someObject.addListener(myListener2); // Register myListener2 as listener.

See also

initialize (AsBroadcaster.initialize method), removeListener (AsBroadcaster.removeListener method)

broadcastMessage (AsBroadcaster.broadcastMessage method)

public broadcastMessage(eventName:String) : Void

Sends an event message to each object in the list of listeners. When the message is received by the listening object, Flash Player attempts to invoke a function of the same name on the listening object. Suppose that your object broadcasts an event message like this:

obj.broadcastMessage("onAlert");

When this message is received, Flash Player invokes a method named onAlert() on the receiving listener object.

Note

You can pass arguments to your listener functions by including additional arguments to the broadcastMessage() method. Any arguments that appear after the eventName parameter are received as arguments by the listener method.

You can call this method only from an object that was initialized by using the AsBroadcaster.initialize() method.

Availability: ActionScript 1.0; Flash Player 6

Parameters

eventName:String - The name of the event to broadcast. The name of any listener methods must match this parameter in order to receive the broadcast event. You can pass arguments to the listener methods by including additional arguments after eventName.

Example

The following example is an excerpt from the first full example provided in the entry for the AsBroadcaster.initialize() method:

someObject.broadcastMessage("someEvent"); // Broadcast the "someEvent"   message.

The following example is an excerpt from the second full example provided in the entry for the AsBroadcaster.initialize() method. It shows how to send arguments to listener methods.

someObject.broadcastMessage("someEvent", 3, "arbitrary string");

See also

initialize (AsBroadcaster.initialize method), removeListener (AsBroadcaster.removeListener method)

initialize (AsBroadcaster.initialize method)

public static initialize(obj:Object) : Void

Adds event notification and listener management functionality to a given object. This is a static method; it must be called by using the AsBroadcaster class (where someObject is the name of the object to be initialized as an event broadcaster):

AsBroadcaster.initialize(someObject);

Note

A common mistake is to capitalize the second letter of AsBroadcaster. When calling the AsBroadcaster.initialize() method, ensure that the second letter is lowercase. Any misspelling of AsBroadcaster fails silently.

This method adds the _listeners property along with the following three methods to the object specified by the obj parameter:

• obj.addListener()

• obj.removeListener()

• obj.broadcastMessage()

Availability: ActionScript 1.0; Flash Player 6

Parameters

obj:Object - An object to serve as a broadcasting object.

Example

The following example creates a generic object, someObject, and turns it into an event broadcaster. The output should be the strings shown in the two trace() statements:

var someObject:Object = new Object(); // Creates broadcast object. var myListener1:Object = new Object(); // Creates listener object. var myListener2:Object = new Object(); // Creates listener object. myListener1.someEvent = function() { // Creates listener method.   trace("myListener1 received someEvent"); } myListener2.someEvent = function() { // Createz listener method.   trace("myListener2 received someEvent"); } AsBroadcaster.initialize(someObject); // Makes someObject an event   broadcaster. someObject.addListener(myListener1); // Registers myListener1 as listener. someObject.addListener(myListener2); // Registers myListener2 as listener. someObject.broadcastMessage("someEvent"); // Broadcasts the "someEvent"   message.

The following example shows how to pass extra arguments to a listener method by using the broadcastMessage() method. The output should be the three strings shown in the three trace() statements, which also include the arguments passed in through the broadcastMessage() method.

var someObject:Object = new Object(); var myListener:Object = new Object(); myListener.someEvent = function(param1:Number, param2:String) {   trace("myListener received someEvent");   trace("param1: " + param1);   trace("param2: " + param2); } AsBroadcaster.initialize(someObject); someObject.addListener(myListener); someObject.broadcastMessage("someEvent", 3, "arbitrary string");

_listeners (AsBroadcaster._listeners property)

A list of references to all registered listener objects. This property is intended for internal use, and is not intended for direct manipulation. Objects are added to and removed from this array by calls to the addListener() and removelistener() methods.

You can call this property only from an object that was initialized by using the AsBroadcaster.initialize() method.

Availability: ActionScript 1.0; Flash Player 6

Example

The following example shows how to use the length property to ascertain the number of listener objects currently registered to an event broadcaster. The following code works if it is added to the first full example in the Examples section of the AsBroadcaster.initialize() entry:

trace(someObject._listeners.length); // Output: 2

For advanced users, the following example shows how to use the _listeners property to list all of the listeners registered with an event broadcaster, along with all of the properties of each listener object. The following example creates two different listener methods for the first listener object.

var someObject:Object = new Object(); // create broadcast object var myListener1:Object = new Object(); // create listener object var myListener2:Object = new Object(); // create listener object myListener1.someEvent = function() { // create listener method   trace("myListener1 received someEvent"); } myListener1.anotherEvent = function() { // create another listener method   trace("myListener1 received anotherEvent"); } myListener2.someEvent = function() { // create listener method   trace("myListener2 received someEvent"); } AsBroadcaster.initialize(someObject); // make someObject an event   broadcaster someObject.addListener(myListener1); // register myListener1 as listener someObject.addListener(myListener2); // register myListener2 as listener var numListeners:Number = someObject._listeners.length; // get number of   registered listeners // cycle through all listener objects, listing all properties of each   listener object for (var i:Number = 0; i < numListeners; i++) {   trace("Listener " + i + " listens for these events:");   for (item in someObject._listeners[i]) {     trace (" " + item + ": " + someObject._listeners[i][item]);   } }

See also

initialize (AsBroadcaster.initialize method)

removeListener (AsBroadcaster.removeListener method)

public removeListener(listenerObj:Object) : Boolean

Removes an object from the list of objects that receive event notification messages.

You can call this method only from an object that has been initialized by using the AsBroadcaster.initialize() method.

Availability: ActionScript 1.0; Flash Player 6

Parameters

listenerObj:Object - The name of a listener object that is registered to receive event notification from the broadcasting object.

Returns

Boolean - Returns true if the listener object is removed, and false otherwise.

Example

The following example shows how to remove a listener from the list of registered listeners. The following code works if it is added to the first full example in the Examples section of the AsBroadcaster.initialize() entry. The TRace() statements are included only to verify that the number of registered listeners is reduced by one after calling the removeListener() method.

trace(someObject._listeners.length); // Output: 2 someObject.removeListener(myListener1); trace(someObject._listeners.length); // Output: 1

See also

addListener (AsBroadcaster.addListener method), initialize (AsBroadcaster.initialize method)