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
Properties inherited from class Object
Method summary
Methods inherited from class Object
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:
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) |