Variable not seeing data on another page

Question

I am trying to read the length of an array on my Application
page from a component. In the component I have this code:
<mx:ApplicationControlBar xmlns:mx="
http://www.adobe.com/2006/mxml"
width="100%" creationComplete="getDPprops()">
<mx:Script>
[Bindable]
public var dpLen:int;
private function getDPprops():void
dpLen = Application.application.flatDP.length;
</mx:Script>
On the Application page I have a handler tied to a method
that creates the FlatDP:
public function returnHandler(e:ResultEvent):void
flatDP = ArrayCollection(e.result);
The odd thing is that when I run the app I get an error
message: "TypeError: Error #1009: Cannot access a property or
method of a null object reference." referring back to the line
where I define dpLen. Which makes me think that flatDP is NULL. But
if I place a label on the same page where the error occurs with a
bindable link back to the length I get the correct length of
flatDP: 625
<mx:Label
text="{Application.application.flatDP.length}"/>
Why does the reference Application.application.flatDP.length
work in the label text, but not when I try to attach it to a
variable in a function?

Answer 1

If I had a working sample, I wouldn't be asking this question
Here is the code for the main app:
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
xmlns:view="com.views.*" layout="vertical"
creationComplete="initApp(event)">
<!--<mx:Script source="asincludes/Dashboard.as"
/>-->
<mx:Script>
<![CDATA[
import mx.charts.HitData;
import mx.collections.ArrayCollection;
import mx.controls.Alert;
import mx.rpc.events.ResultEvent;
[Bindable]
public var flatDP:ArrayCollection;
[Bindable]
public var nNumMonths:int;
[Bindable]
public var nBegin:int;
[Bindable]
public var nEnd:int;
[Bindable]
public var pgeTitle:String;
[Bindable]
public var alertStat:int;
[Bindable]
public var toolGroup:int;
private function initApp(e:Event):void
chartmth_RO.qMonthlyUsage();
public function returnHandler(e:ResultEvent):void
flatDP = ArrayCollection(e.result);
dg.dataProvider = flatDP;
contLine.lineMMR.dataProvider = flatDP;
]]>
</mx:Script>
<mx:RemoteObject id="chartmth_RO" showBusyCursor="true"
destination="ColdFusion"
source="caeusage.src.data.charts_usage_mth">
<mx:method name="qMonthlyUsage"
result="returnHandler(event)" />
</mx:RemoteObject>
<mx:Label text="{flatDP.length}"/>
<mx:DataGrid id="dg" width="75%"/>
<view:cntrLC id="contLine"/>
</mx:Application>
<!-- Here is the composite component (cntrLC) I call at
the end of the main app -->
<mx:VBox xmlns:mx="
http://www.adobe.com/2006/mxml"
width="100%" xmlns:view="com.views.*">
<view:cBarMMR id="acbMMR"/>
<view:chartMMR id="lineMMR"/>
</mx:VBox>
<!-- This is the component cBarMMR that is having the
issue I have added comments with *s in them to show where the
errors occur-->
<?xml version="1.0" encoding="utf-8"?>
<mx:ApplicationControlBar xmlns:mx="
http://www.adobe.com/2006/mxml"
width="100%" creationComplete="getDPprops()">
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
import mx.core.Application;
[Bindable]
public var nBegin:int;
[Bindable]
public var nEnd:int;
[Bindable]
public var dpLen:int;
private function getDPprops():void
//dpLen = Application.application.flatDP.length;<!--
****The error occurs here****-->
set_Thumbs(0);
private function formatSliderDataTip(val:Number):String
return
String(Application.application.flatDP[val-1].abbrvDT);
[Bindable]
public var lineData_array:Array = new Array();
[Bindable]
public var arrayDP:Array = new Array();
/* private function filterFlatDP(p_evt:Event):void <!--
****Also if I uncomment this function I get the same error
message****-->
var arrayDP:Array = Application.application.flatDP.source;
var thumb1:int = p_evt.target.values[0];
var thumb2:int = p_evt.target.values[1];
if(thumb1 < thumb2-1)
lineData_array = arrayDP.slice(thumb1, thumb2);
public function move_Thumbs(m:int):void{
var move:int;
move = nBegin + m;
set_Thumbs(move);
public function set_Thumbs(t1:int):void{
var t2:int;
nBegin = t1;
nEnd = t1 + 120;
]]>
</mx:Script>
<mx:Label
text="{Application.application.flatDP.length}"/>
<mx:HSlider id="dateFilter_sldr"
width="100%"
thumbCount="2"
allowThumbOverlap="false"
minimum="1" maximum="{dpLen}"
dataTipFormatFunction="formatSliderDataTip"
showDataTip="true"
values="{[nBegin, nEnd]}"
tickInterval="24" snapInterval="24"
allowTrackClick="true" liveDragging="true"
change="filterFlatDP(event)"
/>
<!---->
</mx:ApplicationControlBar>