Problem in external XML reading

Question

Hi,
I am trying to develop a birthday application.The aim of the application is to populate all the birthday dates in datechooser and display the appropriate photograph of the person when the highlighted date is clicked.
When I am trying to access {xImages.img[i].BirthDate.toString()} value, it is giving an error : Error #1009: Cannot access a property or method of a null object reference
The following is the code:
Birthday Application
<mx:Script>
        <![CDATA[
            import mx.rpc.events.ResultEvent;
           public var mySource:String="assets/birthday/pictures/1.jpg"
           [bindable]private var xImages:XML
   private function init():void {
                imageData.send();
                dc1.displayedMonth = 2;
                dc1.displayedYear = 2009;
    public function displayDates():void {
                var dateRanges:Array = [];
                for (var i:int=0; i<shows.show.length(); i++) {
                    var cDate:Date =
                        new Date(xImages.img[i].BirthDate.toString());          
                    var cDateObject:Object =
                        {rangeStart:cDate, rangeEnd:cDate};
                    dateRanges.push(cDateObject);
                dc1.selectedRanges = dateRanges;
    function setPath(myPath:String):void
                mainImage.source=myPath;
            function resultHandler(event:ResultEvent):void
                xImages = event.result as XML
                trace (xImages.toXMLString());
        ]]>
    </mx:Script>   
<mx:HTTPService id="imageData" url="assets/birthday/images.xml" resultFormat="e4x" result="resultHandler(event)"/>
<mx:VDividedBox width="20%" height="100%">
    <mx:Panel height="68%" width="100%">
         <mx:DateChooser id="dc1"
        showToday="false"
        creationComplete="displayDates()"
    />   
    </mx:Panel>
    <mx:Panel height="100%" width="100%">
        <mx:Text text="this is for birthday pics"/>
    </mx:Panel>
</mx:VDividedBox>
<mx:Panel width="80%" height="100%">
<mx:VDividedBox width="100%" height="100%">
    <mx:Canvas height="100%" width="100%">
       <mx:Image id="mainImage" source="{mySource}" width="80%" height="80%" verticalCenter="0" horizontalCenter="0" />
    </mx:Canvas>
    <mx:HBox height="20%" width="50%" horizontalScrollPolicy="on" verticalCenter="0">
        <mx:Repeater id="imageRepeater" dataProvider="{imageData.lastResult.img}">
            <mx:Canvas width="55" height="55" backgroundColor="#000000" horizontalScrollPolicy="off" verticalScrollPolicy="off" borderStyle="solid">
                <custom:CustomImage path="{imageRepeater.currentItem.src}" width="89" height="100%" useHandCursor="true" buttonMode="true" source="{imageRepeater.currentItem.thumbnail}" verticalCenter="0" left="0" click="setPath(String(event.currentTarget.path));"/>
            </mx:Canvas>
        </mx:Repeater>
    </mx:HBox>
</mx:VDividedBox>   
</mx:Panel>
</mx:Application>
Example of XML file is as follows:
images.xml
<gallery>
<img>
<src>assets/birthday/pictures/1.jpg
</src> 
<thumbnail>assets/birthday/pictures/t1.gif
</thumbnail>
<BirthDate>02/28/2009</BirthDate>
<title>""</title>
<caption>""</caption>
</img>
<img>
<src>assets/birthday/pictures/2.jpg
</src> 
<thumbnail>assets/birthday/pictures/t2.gif</thumbnail>
<BirthDate>02/12/2009</BirthDate>
<title>""</title>
<caption>""</caption>
</img>
<img>
<src>assets/birthday/pictures/3.jpg
</src> 
<thumbnail>assets/birthday/pictures/t3.gif
</thumbnail>
<BirthDate>02/16/2009</BirthDate>
<title>""</title>
<caption>""</caption>
</img>
</gallery>
Can anybody correct me where I am doing a mistake. I am not able to figure out and is blocked here
Please help me
Thank you in advace,
Cheers,
KK

Answer 1

Hi
You are calling the displayDates() at creationcomplete() of DateChooser. But at that time your xImages(xml) is null because it is not initialized and the HttpServices is not returned the result.
So initialize your xml and call displayDates() after httpservices returns the result.
Hope this helps
Regards
Rush-me