[flexcoders] NavBar - setTargetViewStack

[mikeycmccarthy]

Hi there,

I've written a code behind that manages a ViewStack and a TabBar (it's almost 
like a 
PureMVC mediator without actually being a mediator). The ViewStack is the 
dataprovider of 
the TabBar.

When I try to test this I get the problem that the dataprovider is always null. 
I've attached 
the Flex source code and put it in debug mode and I've noticed it jumps to the 
setTargetViewStack method of NavBar:

private function setTargetViewStack(
                        newStack:Object /* can be String or ViewStack */):void
    {
        // If this property is set at creation time, the target view stack
        // may not exist yet. In this case, we just save off the requested
        // target stack and set it later.
        if (!measurementHasBeenCalled && newStack)
        {
            pendingTargetStack = newStack;
            invalidateProperties();
        }
        else
        {
            _setTargetViewStack(newStack);
        }
    }

Measurement hasn't been called so my dataProvider is null (well, pending). Is 
there any 
way to force this? It's making it really really difficult to do a test!

Thanks in advance!