Error accessing object inside a viewstack

Question

I'm trying to call this when the application initializes:
quote:
public function init():void {
rtByQueues.addEventListener(ChartItemEvent.ITEM_CLICK,
queuesUpdate);
and getting this error:
quote:
TypeError: Error #1009: Cannot access a property or method of
a null object reference.
at template/init()
at template/___template_Application1_initialize()
at
flash.events::EventDispatcher/flash.events:EventDispatcher::dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at mx.core::UIComponent/dispatchEvent()
at mx.core::UIComponent/set processedDescriptors()
at mx.core::Container/createComponentsFromDescriptors()
at mx.core::Container/mx.core:Container::createChildren()
at mx.core::UIComponent/initialize()
at mx.core::Container/initialize()
at mx.core::Application/initialize()
at template/initialize()
at mx.managers::SystemManager/
http://www.adobe.com/2006/flex/mx/internal::childAdded()
at
mx.managers::SystemManager/private::initializeTopLevelWindow()
at mx.managers::SystemManager/private::docFrameHandler()
at [execute-queued]
I figured it out that its because I'm using a ViewStack and
rtByQueues columnchart is inside one of those views. How can I do
the above when using a viewstack like so:
quote:
<viewstack id="views">
<canvas id="view1">
<grid><gridrow><griditem>
<columnchart
id="rtByQueues">...........</columnchart>
and so on....
I'm using flex 3. Thanks!

Answer 1

One approach is to set the creationPolicy="all" for your
ViewStack. However, this can slow down start up times and is often
not the best choice.
<viewstack id="views" creationPolicy="all">
Another approach would be to set the itemClick event listener
directly in your mxml:
<columnchart id="rtByQueues"
itemClick="queuesUpdate()">
This approach seems to be the most efficient since it is only
activated if the particular view is actually needed.
Vygo