DataGrid display problem (was WebService: nested return object)

Question

I am invoking a web service which works fine.
resultFormat = "object"
the event.result = an ArrayCollection, it has two
ObjectProxys wrapping the actual objects.
I can check them in the debugger - the values are as
expected.
Person
personId:long
name:PersonName
PersonName - also wrapped in ObjectProxy
first:String
last:String
The DataGrid will corectly display the dataField="personId".
It displays dataField="name" as '[object Object]'
It displays dataField="name.first" as blank.
Am I navigating this incorrectly?
Will it not navigate complex data types?
Now do I get to the name?
Does resultFormat="object" of the WebService not work?
Must I use resultFormat="e4x"? If so, how do I navigate into
that?
(using FlexBuilder 3)

Answer 1

I can pare it down as far as this, which removes the
WebService from the equation:
<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="
http://www.adobe.com/2006/mxml"
>
<mx:Model id="testModel">
<root>
<partyId>123</partyId>
<name>
<firstName>Bob</firstName>
<lastName>Jones</lastName>
</name>
</root>
</mx:Model>
<mx:Script>
<![CDATA[
import mx.collections.ArrayCollection;
private function find():void {
var persons:ArrayCollection = new ArrayCollection();
persons.addItem(testModel);
grid.dataProvider = persons;
]]>
</mx:Script>
<mx:Button label="fill grid with one item"
id="searchButton" click="find()"/>
<mx:DataGrid id="grid">
<mx:columns>
<mx:DataGridColumn headerText="Column 1"
dataField="partyId"/>
<mx:DataGridColumn headerText="Column 2"
dataField="name"/>
<mx:DataGridColumn headerText="Column 3"
dataField="name.firstName"/>
</mx:columns>
</mx:DataGrid>
<mx:TextArea id="returnText"
text="{grid.dataProvider.toString()}"/>
</mx:Application>