Manipulate data object in a itemrenderer - Adobe Flex 4 - actionscript-3

Question

I have a simple Itemrenderer with the following code:
<?xml version="1.0" encoding="utf-8"?>
<s:ItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
autoDrawBackground="true" width="90" height="90">
<s:VGroup horizontalAlign="center">
<mx:Image source="{data.photo}" toolTip="{data.name}" />
</s:VGroup>
</s:ItemRenderer>
I would like to manipulate the data object before that it's binded to the image attributes (source and tooltip). To do this, I modified the code in this way:
<?xml version="1.0" encoding="utf-8"?>
<s:ItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
autoDrawBackground="true" width="90" height="90"
initialize="itemrenderer1_initializeHandler(event)">
<fx:Script>
<![CDATA[
import mx.events.FlexEvent;
protected function itemrenderer1_initializeHandler(event:FlexEvent):void
{
var obj:Object = this.data;
//here the manipulation
}
]]>
</fx:Script>
<s:VGroup horizontalAlign="center">
<mx:Image source="{data.photo}" toolTip="{data.name}" />
</s:VGroup>
</s:ItemRenderer>
When I try to access to the this.data object, it's always empty! Is there a way to manipulate the data object before binding? Probably i don't have to use this.data, but i cannot find any other object to edit

Answer 1

Another solution would be to override the set data function, like this:
<?xml version="1.0" encoding="utf-8"?>
<s:ItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
autoDrawBackground="true" width="90" height="90"
creationComplete="itemrenderer1_creationCompleteHandler(event)"
>
<fx:Script>
<![CDATA[
import mx.events.FlexEvent;
import valueObjects.Product;
[Bindable]
private var prd:Product;
override public function set data(value:Object):void
{
super.data = value;
//here i can access to the this.data object!
this.prd = this.data as Product;
}
]]>
</fx:Script>
<s:VGroup horizontalAlign="center">
<mx:Image source="{prd.photo}" toolTip="{prd.name}" width="70" />
<mx:Label text="{prd.name}"/>
</s:VGroup>

Answer 2

I found it! I can access to the this.data object only when the creation of the ItemRenderer is completed! to this I have to manipulate the object after the creationComplete event!
Here the code:
<?xml version="1.0" encoding="utf-8"?>
<s:ItemRenderer xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
autoDrawBackground="true" width="90" height="90"
creationComplete="itemrenderer1_creationCompleteHandler(event)"
>
<fx:Script>
<![CDATA[
import mx.events.FlexEvent;
import valueObjects.Product;
[Bindable]
private var prd:Product;
protected function itemrenderer1_creationCompleteHandler(event:FlexEvent):void
{
//here i can access to the this.data object!
this.prd = this.data as Product;
}
]]>
</fx:Script>
<s:VGroup horizontalAlign="center">
<mx:Image source="{prd.photo}" toolTip="{prd.name}" width="70" />
<mx:Label text="{prd.name}"/>
</s:VGroup>
</s:ItemRenderer>

Answer 3

Although not a new thread, do NOT go with CreationComplete. The event is invoked only once. The data will be set whenever the hosting component decides that the itemRenderer should be re-used. E.g. useVirtualLayout=true for a list.