Can't get searchpostprocess to work

[rdownie]

I am trying to get searchpostprocess to work using simple XML. I have my search and I end it with head 10000 and when I run this manually I see the raw results as I would expect.
This is my searchpostprocess section and I get back nothing.

chart count by x_webcat_code_full

column

If I append what I have into the searchTemplate, it works fine. When I try to run it as a post process, it appears to ignore the post processing? I know I must be missing something simple here but can't figure it out. Any help would be appreciated.
Thanks,
Bob

[rdownie]

I figured it out. You need to explicitly pass the fields you want.