Issue in Combobox flex 3.5

Question

Hello all,
I got a serious issue in combobox while using flex sdk 3.5.
The issue is if we filter the collection before creation complete of component and use that filtered collection as a dataprovider for combobox.
If the result from the filtered collection is a blank collection then that combobox is still pouplated from the first value from the source of collection. However the actual result should be null in the selected item of comboBox.
Giving you the sample test code to reproduce the issue.
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:local="*"
     initialize="onInitialize()"     >
     <mx:Script>
          <![CDATA[
               import mx.collections.ArrayCollection;
               [Bindable]
               private var dp:ArrayCollection = new ArrayCollection(['t1','t2','t3']);
               private function filterFunction(inData:Object):Boolean
                    return false;
               private function onInitialize():void
                    dp.filterFunction=filterFunction;
                    dp.refresh()
          ]]>
     </mx:Script>
     <mx:ComboBox id="cb" dataProvider="{dp}" x="66" y="31"/>
     <mx:Button  label="Refresh DP"  x="102" y="92" click="dp.refresh()"/>
</mx:Application>
However it is corrected after refreshing the dataprovider after creation complete. But I don't want to refresh it everywhere thoughout my application.
Please, provide your comments on this.
Thanks
Vikash Kumar

Answer 1

Hi Vikash Kumar,
Just put the initialize event on ComboBox itself instead of Application tag....as shown below...
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" xmlns:local="*"
          >
     <mx:Script>
          <![CDATA[
               import mx.collections.ArrayCollection;
               [Bindable]
               private var dp:ArrayCollection = new ArrayCollection(['t1','t2','t3']);
               private function filterFunction(inData:Object):Boolean
                    return false;
               private function onInitialize():void
                    dp.filterFunction=filterFunction;
                    dp.refresh()
          ]]>
     </mx:Script>
     <mx:ComboBox id="cb" dataProvider="{dp}" x="66" y="31" initialize="onInitialize()"/>
     <mx:Button  label="Refresh DP"  x="102" y="92" click="dp.refresh()"/>
</mx:Application>
Thanks,
Bhasker