Item Renderer in a Datagrid

Question

I'm struggling with how to make a check mark ( image ) show
up or not based on the value of some data in each datagrid line
item. I'm using an item renderer but I'm missing something. Any
help would be greatly appreciated.
thanks,
STeveR

Answer 1

The following is my entire itemrenderer...please excuse any
bad style as this is a WIProgress..
Its probably easier to quote the adobe docs on listdata...If
a component implements the IDropInListItemRenderer interface, you
can use its listData property to obtain information about the data
passed to the component when you use the component in an item
renderer or item editor..I made sure the component implements the
interface as you can see in the code at the top of component. Then
add the couple of required functions regarding listdata, then you
can access the listdata in your own functions in the renderer, like
i do in set data function.
this.BTN_***_mark.label =
value[DataGridListData(listData).dataField];
this line assigns the value from my datagrid to the renderers
button label. (this renderer is a button that the user can press)
so i want the buttons label to show the value coming in from the
datagrid. So listdata is just a way to
explicitly get the column name where the current data is
being sourced from in your datagrid.As the grid is being rendered,
it renders row by row. In each row it goes thru your columns . SO
initially it for row 1 it would begin rendering firstname, surname,
mark, average...etc etc. If i put an alert in on
value[DataGridListData(listData).dataField
I would see these column names popping up as they are getting
rendered in the DGrid.
Hope this helps...
<!-- <?xml version="1.0" encoding="utf-8"?>-->
<mx:VBox xmlns:mx="
http://www.adobe.com/2006/mxml"
creationComplete="init()" width="74" height="30"
horizontalAlign="center" verticalAlign="middle"
implements="mx.core.IFactory,mx.controls.listClasses.IDropInListItemRenderer">
<mx:Metadata>
</mx:Metadata>
<mx:Script>
<![CDATA[
import mx.managers.PopUpManager;
import mx.controls.DataGrid;
import mx.utils.ArrayUtil;
import mx.collections.ArrayCollection;
import mx.collections.IViewCursor;
import mx.controls.Alert;
import mx.events.*;
import mx.controls.dataGridClasses.DataGridListData;
import mx.controls.listClasses.BaseListData;
import mx.controls.dataGridClasses.DataGridColumn;
import mx.containers.TitleWindow;
private var panel:AssessmentMarkPopup = new
AssessmentMarkPopup();
var the_val = 0;
var col_index:int;
private var _listData:BaseListData;
public function get listData() : BaseListData
return _listData;
public function set listData( value:BaseListData ) : void
_listData = value;
private function showLoginForm():void {
var pop:AssessmentMarkPopup =
AssessmentMarkPopup(PopUpManager.createPopUp(this,AssessmentMarkPopup,true));
pop.addEventListener("closepopup",onClose);
pop.TXT_***_mark.text = this.BTN_***_mark.label;
var row:int =
this.parentApplication.DG_class_students.selectedIndex;
pop.student_name =
this.parentApplication.DG_class_students.selectedItem.firstname + "
" + this.parentApplication.DG_class_students.selectedItem.lastname;
private function onClose(e:MyClosePopupEvent):void{
this.BTN_***_mark.label = e.data.mark;
public function newInstance():*
return new MarkEntry();
public override function get data():Object
return super.data;
override public function set data(value:Object):void {
var dg:DataGrid = (listData) ? DataGrid(listData.owner) :
null;
var column:DataGridColumn = (dg) ?
dg.columns[listData.columnIndex] as DataGridColumn : null;
col_index = listData.columnIndex;
var str:String = String(column.dataField);
this.BTN_***_mark.label =
value[DataGridListData(listData).dataField];
]]>
</mx:Script>
<mx:Button click="showLoginForm()" id="BTN_***_mark"
width="52"/>
</mx:VBox>