[flexcoders] Null data for the last dynamically added lineseries

[lmrudner]

After dynamically adding a lineseries, I would like to read the underlying data 
for all the rendered lines. 

In the following code, the top buttons add and remove lines. When a new line is 
added or removed, I call getdata() which posts the available data at the bottom 
of the Panel. 

Immediately after a line is added and displayed, the displayName is available, 
but not the LineSeries data. Yet, as click on the [Read lines] button calls the 
same function and pulls the data!

How can I get the latest lineseries data from the LineChart? Perhaps an 
invalidator or update? I need to read from the LineChart.

Thanks.


[CODE]
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"; layout="absolute">

<mx:Script>
        <![CDATA[
        import mx.controls.Alert;
        import mx.collections.ArrayCollection;
    import mx.charts.series.renderData.LineSeriesRenderData;
    import mx.graphics.Stroke;
    import mx.charts.series.LineSeries;
                        
[Bindable]
private var expensesAC:ArrayCollection = new ArrayCollection( [
{ Month: "Jan", Profit: 2000, Expenses: 1500, Amount: 450 },
{ Month: "Feb", Profit: 1000, Expenses: 200, Amount: 600 },
{ Month: "Mar", Profit: 1500, Expenses: 500, Amount: 300 },
{ Month: "Apr", Profit: 1800, Expenses: 1200, Amount: 900 },
{ Month: "May", Profit: 2400, Expenses: 575, Amount: 500 } ]);


private function updateChart(evt:Event):void {
 if ( evt.currentTarget.selected == true )  {
  addToChart(evt.currentTarget.label);  } 
  else {
  removeFromChart(evt.currentTarget.label); 
 }
  getdata();
}

private function addToChart(item:String):void {
 var newLS:LineSeries = new LineSeries();
    
 newLS.yField = item;
 newLS.displayName = item;
 newLS.setStyle('form','curve');
 newLS.dataProvider = expensesAC;
 //newLS.setStyle('lineStroke',newStroke);
 var tmp:Array = linechart.series; 
 tmp.push(newLS);
 linechart.series = tmp; 
 linechart.invalidateSeriesStyles(); 
}


private function removeFromChart(item:String):void  {
  var objToRemoveIndex:int;
  for ( var i:int = 0; i < linechart.series.length; i++ )
  {
    if ( linechart.series[i].yField == item )  {
  objToRemoveIndex = i;  }
  }
  var tmp:Array = linechart.series; 
  tmp.splice(objToRemoveIndex,1);
  linechart.series = tmp; 
  linechart.invalidateSeriesStyles();    
}

private function getdata():void {
      txt.text = linechart.series.length + " lines in chart \n";
      for ( var i:int = 0; i < linechart.series.length; i++ )    {     
        txt.text +=  linechart.series[i].displayName + " ";
        txt.text += linechart.series[i].items[0].yValue + " " + 
linechart.series[i].items[1].yValue + "\n";
       }
}

private function init():void {
 //addToChart('Amount');
 //Amount.selected = true; 
}

                ]]>
        </mx:Script>

<mx:Panel title="Where is the data?" height="500" width="100%" 
layout="vertical">
  <mx:HBox id="choices" horizontalGap="0">
     <mx:Button id="Profit" label="Profit" toggle="true" 
click="updateChart(event)"/>
     <mx:Button id="Expenses" label="Expenses" toggle="true" 
click="updateChart(event)"/>
     <mx:Spacer height="0"/>
     <mx:Button id="Amount" label="Amount" toggle="true" 
click="updateChart(event)"/>
  </mx:HBox>
 
  <mx:LineChart id="linechart" height="80%" width="100%" showDataTips="true" 
dataProvider="{expensesAC}" creationComplete="init()">
     <mx:horizontalAxis>
         <mx:CategoryAxis categoryField="Month"/>
     </mx:horizontalAxis>
  </mx:LineChart>
  <mx:HBox width="100%" height="69">
                <mx:Legend dataProvider="{linechart}" labelPlacement="right" 
verticalGap="2" direction="vertical"/>
                <mx:Button label="Read lines"  click="getdata()"/>
                <mx:Text id="txt" width="426" height="70"/>
  </mx:HBox>
   
</mx:Panel>
</mx:Application>
[/CODE]