Posts Tagged framework

Some tricks when switching to Robotlegs from PureMVC

From the past posts and a couple of tweets, you all know I have been playing around with Robotlegs. Also, up until now, my framework of choice has been PureMVC, so what I want to do in this post is inform you of the little road bumps I hit when trying to learn the new framework.

Public dependency injection

The first one is really small. Robotlegs makes use of dependency injection (more on that in a later post) and to do so you have to put a meta tag [Inject] before you variable declaration. That is all good, just remember to make your variable public or else you’ll get an error. I wasn’t accustomed with the error I got so it took me some time to find out why I got it.

[Inject]
public var view:Footer; //remember to make public injectable variables

Playing with models

First thing first, when creating my model I was looking to extend the Model class from the Robotlegs framework. Turns out there is no such class; models should extend the Actor class. Services also extends the Actor class.

The next gotcha was a little weird to me at first because it is different from PureMVC mindset. Robotlegs does lazy instantiation, so when you map a model using the injector.mapSingleton method the model will only be created the first time it is injected (that is how I understood it). For some models this is ok, but for others they need to be created before that. In order to do so you use injector.instantiate method and pass it the class you want to create. Here is the code for it and how you would pass data to your newly created model:

injector.mapSingleton(ApplicationModel);
var appModel:ApplicationModel = injector.instantiate(ApplicationModel);
appModel.init("whatever you want here");

Where do I list and handle framework events?

This is the big plus for Robotlegs, no more handling notifications but not listing them and then not figuring out why it doesn’t work. Robotlegs uses the same mechanism, in a mediator, to listen to view events than to listen to framework events which makes it easier to deal with.

So to listen to a view event I would do this:

eventMap.mapListener(view, StringEvent.HIT_ZONE_ROLL_OUT, _onRollOut, StringEvent);

and to listen to a framework event I would do this:

eventMap.mapListener(eventDispatcher, StringEvent.RESIZE, _onResize, Event);

Robotlegs basically wraps around the traditional addEventListener method and what does this give us as an additional bonus? We don’t ever have to set these listeners to weak reference because that is the way they are set by default. Oh, the joy!

Learning a new framework isn’t an easy task (at least when you don’t know any), but I found that learning Robotlegs from a PureMVC background was pretty easy. I hope you will take the time to check it out.

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