Can you create custom events on non-UIComponent based objects in Flex 3?

Question

I have a simple object that get's geocoding data from the Google Maps API and I'd like it to dispatch a set of custom events depending on the response from Google. However, I don't have the addEventListener() and dispatchEvent() methods on this class because it doesn't extend UIComponent. Is there a way to create custom events in Flex 3 without inheriting from UIComponent?

Answer 1

Extend the EventDispatcher class, or implement the IEventDispatcher interface from the flash.events package.

Answer 2

Yes, that should be possible. Extend EventDispatcher like this:

  import flash.events.*;  
  public class MyDispatcher extends EventDispatcher { 
    private function doIt(event:Event):void {  
      dispatchEvent(new Event("myEvent"));  
  }

Answer 3

Absolutely yes. To take advantage of event handling, your custom object should extend EventDispatcher:

public class MyClass extends EventDispatcher
{
    // ...

    public function myFunction():void
    {
     dispatchEvent(new Event("myEvent"));
    }
}

This takes care of dispatching events.

Then as well, if you have the need, you can also create a separate class that extends Event, which gives you the option (among other things) of attaching event-specific data for use in the handler:

public class MyClass extends EventDispatcher
{
    // ...

    public function myFunction():void
    {
     dispatchEvent(new MyEvent(someData));
    }
}

public class MyEvent extends Event
{
    private var _myEventData:Object;

    public function MyEvent(eventData:Object)
    {
     _myEventData = eventData;
    }
}

.. so then in your handler, you'd just:

private function myHandler(event:MyEvent):void
{
    trace(event.myEventData.toString());
}

Make sense?

Answer 4

That's exactly what I did! extended EventDispatcher and inherited dispatchEvent

Thanks lads