[Zope] ZCatalog: how to only catalog items with a specific property?

[Philipp Robbel]

Hi fellow Zopists,

I'm trying to figure out how to only select certain DTMLDocuments with a
specific property into the ZCatalog via the "Find Objects" Screen.

On that Find Objects screen there's a field called "expr" .. it somehow
works because entering "1 == 1" selected every DTML Document while "1 == 2"
selected none. My problem is that I couldn't figure out the valid statement
for selecting only Documents with the certain property "NON_CATALOGED" not
set.

"hasattr(self,'NON_CATALOGED')"

did not work... i'm lost, even looking at those source didn't help...

Any guru around?

Thanks in advance,
Philipp Robbel