[Dahan]

Прежде почитай вот эту статью http://techrays.wordpress.com/2008/1...r-re-grouping/

как я могу сохранить dataProvider в xml?

Да вот так например:

<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009" 
                       xmlns:s="library://ns.adobe.com/flex/spark" 
                       xmlns:mx="library://ns.adobe.com/flex/halo" 
                       creationComplete="create()">
    <fx:Script>
        <![CDATA[

            import flash.events.MouseEvent;
 
            import mx.collections.XMLListCollection;
 
            [Binable]
            public var xmllc:XMLListCollection; 
 
            protected function create():void
            {
                xmllc = new XMLListCollection(myXML.children());
                myDG.dataProvider = xmllc;
            }
 
            protected function xml_clickHandler(event:MouseEvent):void
            {
                myXML.replace(myXML.children(),(myDG.dataProvider as XMLListCollection).source);
                xmlOut.text = myXML;
            }

        ]]>
    </fx:Script>
    <fx:Declarations>
        <!-- Place non-visual elements (e.g., services, value objects) here -->
        <fx:XML 
            xmlns="" id="myXML">
            <main>
                <child name='odin'/>
                <child name='dva'/>
                <child name='tri'/>
            </main>    
        </fx:XML>
    </fx:Declarations>
    <mx:DataGrid 
        x="10" 
        y="10" 
        id="myDG" 
        editable="true">
        <mx:columns>
            <mx:DataGridColumn headerText="Столбец 1" dataField="@name"/>
        </mx:columns>
    </mx:DataGrid>
    <s:TextArea x="9" y="189" width="303" height="226" id="xmlOut"/>
    <s:Button x="10" y="160" label="XML" click="xml_clickHandler(event)"/>
</s:WindowedApplication>

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