Flex, Ruby, etc. etc.

I’ve updated Chandima Cumaranatunge’s excellent PureMVC walk-through to work with the latest version of PureMVC (2.0.3). Although PureMVC has extensive documentation nothing beats a simple demo for wrapping your brain around the framework. The most helpful part of Chandima’s tutorial is when he steps through the sequence of actions which includes initialization and then following a user’s gesture on a round trip through the framework.

1. The Concrete Facade class called ApplicationFacade broadcasts a STARTUP Notification.

2. The STARTUP Notification triggers the StartupCommand command object which registers the KeyDataProxy proxy, and StageMediator mediator.

3. StageMediator mediator registers a KEY_DOWN Event handler to the stage to intercept key presses. It also registers to receive KEYUPDATE Notifications.

4. User presses a key generating a KEY_DOWN Event that is intercepted by the key down event handler in the StageMediator.

5. StageMediator broadcasts a KEYDOWN Notification with the character code of the key in the notification body.

6. The KEYDOWN Notification triggers the StoreKeyCommand command object, which accesses the KeyDataProxy proxy and updates the model (data object).

7. The KeyDataProxy proxy stores the data in a data object (just a property in the proxy in this case).

8. The KeyDataProxy proxy broadcasts a KEYUPDATE Notification with the character code of the key in the notification body.

9. The KEYUPDATE Notification handler in StageMediator intercepts the KEYUPDATE Notification and traces the key value.

In my updated example I trace out each action to clarify when (and in which file) they occur. Make sure you have PureMVC in your class path before running the demo.