This is not a feature request for Ext.Net, rather for ExtJs. Can you please file it at ExtJs forums for me...

In almost all places, ExtJs allows you to specify element ids, html element or ExtJs element interchangeably. However, the return value for a GridPanel column renderer function needs to be html string only.

Can you please file a feature request for ExtJs for allowing returning html/extjs elements from GridPanel column renderers??