I have a AdvancedDataGridColumn with custom itemrenderer which displays undefined in the group summary field. How do I get rid of it? I have included the code and a screenshot
<mx:AdvancedDataGridColumn dataField="import_type" headerText="Workflow">
<mx:itemRenderer>
<fx:Component>
<s:MXAdvancedDataGridItemRenderer>
<s:Label left="5" right="5" verticalCenter="0"
text="{data.import_type} , {data.export_type}"/>
</s:MXAdvancedDataGridItemRenderer>
</fx:Component>
</mx:itemRenderer>
</mx:AdvancedDataGridColumn>