CODEWITHSUNDEEP
apache-flexactionscript-3actionscript
Radu
Radu

Reputation: 1104

MVC principile in flex/as3

I am currently working on several flex projects, that have gone in a relative short amount of time from prototype to almost quite large applications.
Time has come for some refactoring to be done, so obviously the mvc principle came into mind.
For reasons out my control a framework(i.e. robotlegs etc.) is not an option.
Here comes the question...what general guidelines should I take into consideration when designing the architecture?

Also...say for example that I have the following: View, Ctrl, Model.

From View:

var ctrlInstance:Ctrl= new Ctrl();
ctrl.performControllerMethod();

In Controller

public function performControllerMethod():void{
    //dome some sort of processing and store the result in the model.
    Model.instance.result = method_scope_result;
}

and based on the stored values update the view.
As far as storing values in the model, that will be later used dynamically in the application, via time filtering or other operation, everything is clear, but in cases where data just needs to go in(say a tree that gets populated once at loading time), is this really necessary to use the view->controller->model->view update scheme, or can I just make the controller implement IEventDispatcher and dispatch some custom events, that hold necessary data, after the controller operation finished.

Ex:
View:

var ctrlInstance:Ctrl= new Ctrl();
ctrl.addEventListener(CustomEv.HAPPY_END, onHappyEnd);
ctrl.addEventListener(CustomEv.SAD_END, onSadEnd);
ctrl.performControllerMethod();


Controller

public function performControllerMethod():void{
   (processOk) ? dispatchEvent(new CustomEv(CustomEv.HAPPY_END, theData)) : dispatchEvent(new CustomEv(CustomEv.SAD_END));
}


When one of the event handlers kicks into action do a cleanup of the event listeners(via event.currentTarget).


As I realize that this might not be a question, but rather a discussion, I would love to get your opinions.

Thanks.

Upvotes: 0

Views: 246

Answers (1)

Amy Blankenship
Amy Blankenship

Reputation: 6961

IMO, this whole question is framed in a way that misses the point of MVC, which is to avoid coupling between the model, view, and controller tiers. The View should know nothing of any other tier, because as soon as it starts having references to other parts of the architecture, you can't reuse it.

Static variables that are not constant are basically just asking for trouble http://misko.hevery.com/2009/07/31/how-to-think-about-oo/. Some people believe you can mitigate this by making sure that you only access these globals by using a Controller, but as soon as all Views have a Controller, you have a situation where the static Model can be changed literally from anywhere.

If you want to use the principles of a framework without using a particular framework, check out http://www.developria.com/2010/04/combining-the-timeline-with-oo.html and http://www.developria.com/2010/05/pass-the-eventdispatcher-pleas.html . But keep in mind that established frameworks have solved most of the issues you will encounter, you're probably better off just using one.

Upvotes: 1

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