Comments on: Why PureMVC Kicks Ass (and one reason it doesn’t)

By: Tyreseby

Tyreseby — Wed, 19 Mar 2008 09:23:57 +0000

thanks much, bro

By: lauren

lauren — Wed, 13 Feb 2008 15:47:14 +0000

Jackson:
It does make sense to have the mediators responsible for their own names. And this was the course we took in the instance where we needed them to be dynamically named, they grab their name from the uid of the view they are mediating.
This becomes a problem in retrieving the mediator if you do not have access to the view component, therefore do not know the name of the mediator you are trying to use.
In that case, static names are a plus. We have stated to use static names for our mediators that may be called on from more than one component and will never be instantiated more than once, such as the entire application mediator.

By: Jackson

Jackson — Tue, 12 Feb 2008 18:33:11 +0000

Wouldn’t it make more sense to have the mediator be responsible for dynamically naming themselves? The mediators are inherently bound to the views via there instantiation and would be intelligent enough to offer up, or act on there own, unique name.

By: lauren

lauren — Thu, 10 Jan 2008 19:00:09 +0000

Cliff
You are right, the proxies and mediators dont HAVE to be single instances. However, it seems as though you were assuming most developers would use them that way. Especially with retrieving mediators by name, the static name makes them easily accessible.

The example in the HelloFlash demo is similar to how we set up our system, using the view to dynamically name the mediators. We found that there wasn’t too much documentation about a system like that so far, as most of the examples stick to the single instances with static names. Aside from one or two posts in the forum, we decided to bring the issue out a little and discuss. To showcase our way of doing it and give others some ideas on how to go about finding a solution to their own needs.

By: Cliff Hall

Cliff Hall — Thu, 10 Jan 2008 17:14:34 +0000

>>The biggest downfall so far is the fact that the mediators and proxies are expected to be singletons.

This is not correct. Proxies and Mediators are not singletons. The only singletons in the system are Facade, Model, View and Controller.

You may have only looked at one or two demos and found that OFTEN, there is only one instance of a given Mediator or Proxy in the in the system, but this is not always the case.

For instance, to see a Mediator that is instantiated multiple times at runtime, check out the HelloFlash demo, in which you grab a colored square on the screen and drag it, causing it to emit further colored squares.

The colored square is a HelloSprite, and each one has an associated HelloSpriteMediator. When you use the scrollwheel to resize all the sprites, what is happening is that a notification is being broadcast that all instances of HelloSpriteMediator hear and in turn resize their associated HelloSprite.

Note that each HelloSpriteMediator is given a unique name.

Whether a given Mediator or Proxy is instantiated more than once depends entirely upon what it is you’re trying to do.

-=Cliff>