Anyone successfully inherited from CoreResultsWebpart with FAST Search as the provider?

Question

I created a dummy webpart which inherits the CoreResultsWebpart. If I add the built-in SharePoint Search SSA to the default application proxy group, this webpart renders results just like the normal Core Results WebPart.

If I however set up SP2010 against FAST instead, and add the FAST Query SSA to the default proxy group, then nothing is displayed. The oob Core Result Webpart works of course.

Either there is some quirk to get this working, or there's a bug somewhere. I've tried it on two separate farms, with the same outcome.

Answer 1

We had a similar problem on extending CoreResultsWebpart, the problem was in .webpart file properties list, which lacked of some entries such as ScopeID, RelevanceView, etc.

We updated the list (copying properties from the original webpart), re-deployed, removed and reinserted webpart on sharepoint page, and all went ok.