I have a list and when I select an item I want to update a form.  So say the list has Person objects and when you select one a Form (in the same View) has a Name and Age field that get populated with the selected object.

Is it best to keep a, "private var selected:PersonVO" in the view or should I keep "selected" in the proxy?  If I keep it in the proxy, I'd have to have my view catch the "list change" event, fire off an event, the mediator would catch it and do "proxy.selected = view.list.selectedItem".  Then the proxy would maybe send out a notification, the mediator would catch the notification and populate the form.

Would the notification be defined in the ApplicationFacade?  (i.e. public static const PERSON_SELECTED:String ="personSelected");

Also, if it did go the route of sending an event and so on, I would need a "PersonSelectedCommand" right?  Since the mediator shouldn't talk directly to the proxy, it should use a notification.

Is one "better" than the other?

Well instead of having my BarViewMediator do:

:

view.listBarObjects.dataprovider = data;

I instead put a bindable ArrayCollection in my BarView and bound the dataProvider of the list to it.

:

[Bindable] public var data:ArrayCollection = new ArrayCollection();
...
...
<mx:List id="listBarObjects" dataProvider={data}" />

Now in my BarViewMediator I have:

:

view.data = data;

and it works.

So I followed he helpful information (for ViewStack at least): http://forums.puremvc.org/index.php?topic=280.0

However I still have the same problem.

ApplicationMediator

:

public function ApplicationMediator(viewComponent:Object=null)
{
super(NAME, viewComponent);

view.addEventListener(AppMain.EVT_SHOW_FOO, onShowFoo);
view.addEventListener(AppMain.EVT_SHOW_BAR, onShowBar);
checkForMediator(view.currentViewSelector, view.activeView);
}
protected function onShowFoo(e:Event):void {
view.currentViewSelector = AppMain.VIEW_FOO;
checkForMediator(AppMain.VIEW_FOO, view.activeView);
sendNotification(ApplicationFacade.FOO_MODE);
}
protected function onShowBar(e:Event):void {
view.currentViewSelector = AppMain.VIEW_BAR;
checkForMediator(AppMain.VIEW_BAR, view.activeView);
sendNotification(ApplicationFacade.BAR_MODE);
}
        protected function checkForMediator( childSelector:int, child:Object ):void {
        switch (childSelector) {
        case AppMain.VIEW_FOO:
        if (facade.retrieveMediator(FooViewMediator.NAME) == null) {
        facade.registerMediator(new FooViewMediator(child));
        }
        break;
        case AppMain.VIEW_BAR:
if (facade.retrieveMediator(BarViewMediator.NAME) == null) {
        facade.registerMediator(new BarViewMediator(child));
        }
        break;
        }
        }

AppMain.mxml

:

<mx:Script>
<![CDATA[
import mx.events.ItemClickEvent;
import mx.rpc.events.FaultEvent;

public static const EVT_SHOW_FOO:String = "showFoo";
public static const EVT_SHOW_BAR:String = "showBar";

public static const VIEW_FOO:int = 0;
public static const VIEW_BAR:int = 1;

[Bindable] public var currentViewSelector:int = VIEW_FOO;
public var activeView:Object = viewEvents;

private var facade:ApplicationFacade = ApplicationFacade.getInstance();

private function init():void {
activeView = viewStack.selectedChild;
facade.startup(this);
}

private function submit(action:String):void {
dispatchEvent(new Event(action, true));
}
]]>
</mx:Script>

<mx:Binding source="viewStack.selectedChild" destination="activeView" />

<mx:ApplicationControlBar id="appControlBar" width="65%" dock="true">
<mx:Button id="buttonFoo" label="Foo" click="submit(EVT_SHOW_FOO)" />
<mx:Button id="buttonBar" label="Bar" click="submit(EVT_SHOW_BAR)" />
</mx:ApplicationControlBar>

<mx:ViewStack id="viewStack" width="100%" height="75%"
selectedIndex="{currentViewSelector}">

<components:FooView id="viewFoo" width="100%" height="100%" />

<components:BarView id="viewBar" width="100%" height="100%" />
</mx:ViewStack>

So when the app first starts up you see the "FooView".  When I click on the "Bar" button I get the NULL reference error in my BarViewMediator when I try to set the dataProvider on my "listBarObjects":
BarViewMediator.as

:

public function BarViewMediator(viewComponent:Object=null) {
super(NAME, viewComponent);

var data:ArrayCollection = new ArrayCollection();
for (var i:int = 0; i < 5; i++) {
var q:BarVO = new BarVO ();
q.name = "Bar " + (i+1);
q.msg = "something random here - " + i;
data.addItem(q);
}

view.listBarObjects.dataProvider = data;
}

Did I miss something about how to handle this deferred instantiation?  When I debug I can see that the "checkForMediator" method gets called when I click the "Bar" button and I see it creates a new "BarViewMediator" and passes it the "BarView" object, however the "listBarObjects" is null.

Sorry for the mix up.

I originally stated that the ApplicationMediator passes the FooView to the FooMediator by doing view.FooView

Application.mxml

:

<mx:application...>
    ...
    <components:FooView id="FooView" />
    ...
</mx:application>

ApplicationMediator.as

:

public function ApplicationMediator(...) {
   ...
   facade.registerMediator(new FooMediator(view.FooView));
}

private function get view():Application {
      return viewComponent as Application;
}

So I am passing in a FooView.

I am using the standard version.

FooView is a child of the "view".

view.dummyButton is null but "view" is not (as i could see in the debugger).

Not really sure what the issue is.  Should I register the view.dummyButton.addEventListener somewhere else besides the constructor?  I think it's ok to do it in the constructor since I've done it elsewhere and the samples do it.

thanks.

I have the following setup:

StartupCommand creates ApplicationMediator
ApplicationMediator creates FooMediator (and passes it view.FooView)

The FooMediator constructor looks like:

:

public function FooMediator(viewComponent:Object=null) {
      super(NAME, viewComponent);
      view.dummyButton.addEventListener(....);
}

private function get view():FooView {
   return viewComponent as FooView;
}

I get the following on the "view.dummButton.addEventListener" line:
Cannot access a property or method of a null object reference.

In the debugger I see that "dummyButton" is null.

The FooView looks like:

:

<mx:Panel ....>
<mx:Button id="dummyButton" label="Close" />
</mx:Panel>

Any ideas?

I spoke (actually emailed) with Cliff about the disappearance of the courseware (I too had seen it referenced around on the 'net) and on July 24, 2008 he said:

Sorry, but the courseware beta test program has closed. The courseware is in the process of being updated now. Keep an eye out on the site for more info.

I have a Flex project in FlexBuilder3 which also has a pom.xml.  I have added the following to my pom.xml:

:

<dependency>
<groupId>org.puremvc</groupId>
<artifactId>puremvc_as3</artifactId>
<version>2.0.3</version>
<classifier>swc</classifier>
</dependency>

However, FlexBuilder gives me two errors:
1017: The definition of base class Facade was not found.
1020: Method marked override must override another method.

The lines of code that those two errors reference to, respectively, are:

:

public class ApplicationFacade extends Facade
and

:

override protected function initializeController():void {

Do I need to add PureMVC to my "Flex Build Path" (i.e. under the "Properties" for my Flex project)?  If so, I thought by having Maven include the dependency I didn't need to do that.

Thanks!