R – Providing values to components in a dataGrid

if you create your own itemEditor/itemRenderer you can do something like:

<mx:TextInput xmlns:mx="..." change="onChange(event)"
    implements="mx.controls.listClasses.IDropInListItemRenderer">
    <mx:Script>
        <![CDATA[

        import mx.controls.dataGridClasses.DataGridListData;
        import mx.controls.listClasses.BaseListData;
        [Bindable("dataChange")] private var _listData : BaseListData;
        public function get listData():BaseListData
        {
            return _listData;            
        }                   
        public function set listData( value : BaseListData ) : void
        {
            _listData = value;
        }

        private function onChange(event:Event):void
        {
             this.data[ (listData as DataGridListData).dataField ] = this.text;
        }
        ]]>
    </mx:Script>
</mx:TextInput>

hope this helps.

You do need to write an item renderer to do this. However, you want to update the state of the render whenever the "data" property is set. This is important since item renderers are recycled. Basically the data property gets set whenever the data for that renderer changes and this happens as you scroll the DataGrid.

Here's a simple Application with a DataGrid:

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" creationComplete="onCreationComplete()">

<mx:Script>
    <![CDATA[
        import mx.collections.ArrayCollection;

        [Bindable] private var collection:ArrayCollection;

        private function onCreationComplete():void
        {
            collection = new ArrayCollection();
            for (var i:uint = 0; i < 20; i++)
                collection.addItem({name:'Person #'+i});
        }

    ]]>
</mx:Script>

<mx:DataGrid width="600" dataProvider="{collection}" rowCount="5">
    <mx:columns>
        <mx:DataGridColumn itemRenderer="com.foo.ItemRenderer"/>
    </mx:columns>
</mx:DataGrid>

</mx:Application>

And a simple MXML-based renderer:

<mx:HBox xmlns:mx="http://www.adobe.com/2006/mxml">

<mx:Script>
    <![CDATA[

        override public function set data(value:Object):void
        {
            super.data = value;
            // only show radio buttons if the "name" property of the data contains "5"; otherwise show a label
            radioS.visible = radioS.includeInLayout = radioM.visible = radioM.includeInLayout = radioL.visible = radioL.includeInLayout = data.name.indexOf(5) > -1;
            labelName.visible = labelName.includeInLayout = data.name.indexOf(5) < 0;               
        }

    ]]>
</mx:Script>

<mx:Label id="labelName" text="{data.name}"/>
<mx:RadioButton id="radioS" label="Small" groupName="radioGroup"/>
<mx:RadioButton id="radioM" label="Medium" groupName="radioGroup"/>
<mx:RadioButton id="radioL" label="Large" groupName="radioGroup"/>

</mx:HBox>