Using xml as dataProvider for chart

Question

I am trying to use a loaded xml as the dataProvider for a pie chart like this
<mx:PieChart id="pieChart"
                     dataProvider="{get_xml.lastResult.AssetAllocationFunds.fund[0].target_allocation}">
This works, but gives a warning that
"Data binding will not be able to detect changes when using the square bracket operator. For Array, please use ArrayCollection.getItemAt() instead."
Can someone give me some direction on how to implement this.
Thanks.

Answer 1

So that solution I posted up wasn't going to work for what I needed.
Basically, the "itemRollOver" and "itemClick" that work for the pie chart when hard coded on the main application don't work when embedded in a custom class that extends the PieChart. I haven't been able to figure out why.
However, I did get the syntax for targeting ArrayCollection.getItemAt() worked out.
Here is a simple example.
Hope it helps others.
Mark
<?xml version="1.0" encoding="utf-8"?>
<s:Application
    xmlns:fx="http://ns.adobe.com/mxml/2009"
    xmlns:mx="library://ns.adobe.com/flex/mx"
    xmlns:s="library://ns.adobe.com/flex/spark"
    >
    <fx:Script>
        <![CDATA[
            import mx.charts.events.ChartEvent;
            import mx.charts.events.ChartItemEvent;
            import mx.charts.series.items.PieSeriesItem;
            import mx.collections.ArrayCollection;
            import mx.events.FlexEvent;
            import mx.rpc.events.ResultEvent;
            import mx.charts.series.PieSeries;
            private function pieChart_itemRoll(evt:ChartItemEvent):void {
                var psi:PieSeriesItem = evt.hitData.chartItem as PieSeriesItem;
                myTextArea.text += "\rtarget: "+psi.item.target;
                trace(psi.item.target);
            private function pieChartClick(event:ChartItemEvent, pieName:String):void{   
                myTextArea.text += "\rid: "+pieName;
            [Bindable]
            private var chartData:ArrayCollection = new ArrayCollection(
                [[{target:"Target A0",percent:40},
                    {target:"Target A1",percent:30},
                    {target:"Target A2",percent:20},
                    {target:"Target A3",percent:10}],
                    [{target:"Target B0",percent:45},
                        {target:"Target B1",percent:22},
                        {target:"Target B2",percent:17},
                        {target:"Target B3",percent:8}]]);
        ]]>
    </fx:Script>
    <s:VGroup>
        <s:HGroup id="myGroup">
            <mx:PieChart
                dataProvider="{chartData.getItemAt(0)}"
                itemRollOver="pieChart_itemRoll(event);"
                itemClick="pieChartClick(event, 'pie 0');"
                showDataTips="false"
                height="210"
                width="210">
                <mx:series>
                    <mx:PieSeries
                        field="percent"
                        nameField="target"
                        labelPosition="inside"
                        >
                    </mx:PieSeries>
                </mx:series>
            </mx:PieChart>
            <mx:PieChart
                dataProvider="{chartData.getItemAt(1)}"
                itemRollOver="pieChart_itemRoll(event);"
                itemClick="pieChartClick(event, 'pie 1');"
                showDataTips="false"
                height="210"
                width="210">
                <mx:series>
                    <mx:PieSeries
                        field="percent"
                        nameField="target"
                        labelPosition="inside"
                        >
                    </mx:PieSeries>
                </mx:series>
            </mx:PieChart>
        </s:HGroup>
        <s:TextArea id="myTextArea"  width="550" height="220" />
    </s:VGroup>
</s:Application>