I noticed that the itemRenderer is applied column-wise. I was wondering if it is possible to use ItemRenderer only for a few rows in the ADG. I want the itemRenderer to be applied to parent nodes and all their children. But if a row doesn't have children, I don't want it to be renderer by an ItemRenderer. Any idea of how to achieve that? Thanks.
Yes. You'll need to use the ADG's rendererProviders property. It's an array of AdvancedDataGridRendererProviders (http://livedocs.adobe.com/flex/3/langref/mx/controls/advancedDataGridClasses/AdvancedDataG ridRendererProvider.html). The documentation is pretty good, but basically you set a bunch of properties on each ADGRP, and the grid figures out from those properties what renderers to use on the fly. Its exactly what you need for different renderers at different levels in a hierarchy.