Custom Event in actionscript 3

Adding custom event in as3 can make life easy. Sometime it needs to set root variable from different class or need to call root function for a specific application. Its better to use custom event than using "root" in class. Its easy to trigger and also can be listen from anywhere. Its make a class independent. Creating custom event handlers in ActionScript 3 is pretty much simple. Here i’m showing a simple myCustomEvent class which extends the flash Event class.

   1: //Declare a class for myCustomEvent

   2: package wneeds.events{

   3:     

   4:     import flash.events.Event;

   5:  

   6:     public class myCustomEvent extends Event {

   7:         

   8:         public var myMessage:String;

   9:         

  10:         public function myCustomEvent(msg) {

  11:             

  12:             super("myCustomEvent");

  13:             myMessage = msg;

  14:         }

  15:     }

  16: }

In the above class i also declare a variable named "myMessage" to show how to pass variable in a custom event class. For triggering the custom event, it just need to include the class and use the dispatchEvent method as like below…

   1: //How to asign a event

   2: import wneeds.events.myCustomEvent;

   3:  

   4: dispatchEvent(new myCustomEvent("Hello ..."));

Now time to add Listener to listen the event from anywhere….

   1: //How to add the listener for the myCustomEvent..

   2:  

   3: this.addEventListener("myCustomEvent", showMessage);

   4:  

   5: function showMessage(e:myCustomEvent):void {

   6:     trace(e.myMessage);

   7: }

In various purpose its better to pass object. Because in object its easy to pass multiple properties and easy to write in json format.

   1: dispatchEvent(new myCustomEvent({name:'tma',height: 100, msg : 'Hello...'}));

Then it can be easily possible to get all the properties from the listener….