Why received this Mediator the STARTUP Event?

[Oscar]

Hi,

just a generally question.
Let's say we have this simple Application:

ApplicationFacade Class:

:


//...............

public function startup(app:App):void
{
       sendNotification(STARTUP, app);
}
 
// Register Commands with the Controller
override protected function initializeController():void
{
       super.initializeController(); 
       registerCommand(STARTUP, StartupCommand); 
}

//..................

StartupCommand Class:

:



//.........

override public function execute(notification:INotification):void
{
var app:App = notification.getBody() as App;
var mediatorName:String = AppMediator.NAME;

facade.registerMediator(new AppMediator(mediatorName, app));
}

//.......


AppMediator Class:

:


//.......
override public function handleNotification(note:INotification):void
{
switch(note.getName())
{
case ApplicationFacade.STARTUP:
    trace("AppMediator recivied the STARTUP EVENT");
    break;
}
}

override public function listNotificationInterests():Array
{
return [
    ApplicationFacade.STARTUP
];
}

//.......



App Class

:


//........

public function App()
{
    var facade:ApplicationFacade = ApplicationFacade.getInstance();
    facade.startup(this);
}

//.........


Like you can see, the AppMediator listening for the STARTUP Event.
When you start this Application he also received this Event. Exactly this makes me curios.
Let's take a look at the start order:

1.) "App" initializes the ApplicationFacade and call the startup function.
2.) The ApplicationFacade sends a STARTUP Event.
3.) Because the Controller listens for this Event, he create/start the "StartupCommand".
4.) This Command create the "AppMediator" ...

At Point 2 the STARTUP Event is throwing. At this Point the "AppMediator" doesn't exist.
Only now at Point 4, the Command creates the Mediator. 

So, why the "AppMediator" actually received the STARTUP Event?

[puremvc]

The Command was the first and only observer for the STARTUP notification. However, before it finished executing, it created and registered the Mediator.

During registration of the Mediator, it is interrogated as to its notification interests, and you have said it is interested in the STARTUP notification, therefore it is placed on the observer list for the STARTUP notification.

Then the Mediator is registered and the Command is complete, and the loop over the STARTUP notification observer list continues. The Mediator is now in this list and so it is notified.

-=Cliff>