Jason -
Clicking the button will generate a collection change event, but will
not trigger data binding because the value of _dataProvider is not
changing (no assignment is being made to the _dataProvider member). If
you want to know when items are added to/removed from the collection you
will need to listen for events as follows.
public function set dataProvider (_dp:ArrayCollectio n) :void
{
_dataProvider = _dp;
//listen for collection change events, use weak references so we
don't cause a leak
_dataProvider.addEventListener(CollectionEvent.COLLECTION_CHANGE,
handleCollectionChanged, false, 0, true);
showData();
trace("databinding triggered")
}
hth
Scott
Scott Melby
Founder, Fast Lane Software LLC
http://www.fastlanesw.com
Sherif Abdou wrote:
you could always just do nameOfComponent.dataProvider = fakedata and
that work but i dont know if that is what you are looking for.
----- Original Message ----
From: "Merrill, Jason" <[EMAIL PROTECTED]>
To: flexcoders@yahoogroups.com
Sent: Monday, February 4, 2008 1:50:32 PM
Subject: [flexcoders] Databinding in component
*Why does the button click below not trigger databinding in the
component (i.e. automatic call of set dataprovider) ?*
Here is my test case:
//MXML:
<?xml version="1.0" encoding="utf- 8"?>
<mx:Application
xmlns:mx="http://www.adobe. com/2006/ mxml
<http://www.adobe.com/2006/mxml>" xmlns:c="components .*"
layout="absolute"
applicationComplete ="init()" >
<mx:Script>
<![CDATA[
import mx.collections. ArrayCollection;
[Bindable]
public var fakeData:ArrayColle ction;
private function init():void
{
fakeData = setFakeData( );
}
private function setFakeData( ):ArrayCollectio n
{
var fd:ArrayCollection = new ArrayCollection( );
fd.addItem({ firstName: "David", lastName:"Branson" });
fd.addItem({ firstName: "Ned", lastName:"Davidson" });
fd.addItem({ firstName: "Sally", lastName:"Peterson" });
return fd;
}
private function changeData() :void
{
fakeData.addItem( {firstName: "Jason", lastName:"Merrill" });
}
]]>
</mx:Script>
<c:BindableListText dataProvider= "{fakeData} " />
<mx:Button x="100" label="change data" click="changeData( )"/>
</mx:Application>
/*========== ========= ========= ========= ========= ========* /
//Component:
package components
{
import flash.events. Event;
import mx.controls. TextArea;
import mx.collections. ArrayCollection
import mx.core.UIComponent ;
public class BindableListText extends UIComponent
{
[Bindable]
private var _dataProvider: ArrayCollection;
private var tf:TextArea;
public function BindableListText( )
{
tf = new TextArea();
tf.height = 400;
tf.width = 400;
addChild(tf)
}
public function set dataProvider (_dp:ArrayCollectio n) :void
{
_dataProvider = _dp;
showData();
trace("databinding triggered")
}
private function showData():void
{
var dpLen:int = _dataProvider. length;
tf.text = "";
for(var i:int = 0; i<dpLen; i++)
{
tf.text += _dataProvider. getItemAt( i).firstName+ "\n";
}
}
}
}
Jason Merrill
*Bank of America *
GT&O L&LD Solutions Design & Development
eTools & Multimedia
*Bank of America Flash Platform Developer Community*
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