user function in task reports

Question

I am trying to create a text column with properties from the user function inside a process report. 
 I want to create a text field with "firstName lastName". I want to utilize tp!owner or the tp!assignees 
 The user function is suppose to be compatible with reports but when I try to use it doesn't return anything.

Mike Schmitt · Answer

You'll need to remember that tp!assignees, at least, is by default a "list of user or group", and thus you'd need to do some more fiddling with whatever its value holds before being able to call any functions on it in a meaningful way. The back-end logic in reports is old, and the quirks/exceptions/special cases are not very well documented (most of the ones I know about were found just by trial and error), so this is always a touchy thing to try and mess with - especially so because using any rules/functions in the display logic is touchy, and some just plain don't work . 
 (edit to add: i also confirm that user() doesn't seem to work at all even after controlling for the stuff I mentioned above, though I'm not very surprised by this.) 
 Depending on the end result you're after, I'd more strongly recommend querying the information into a SAIL form and then displaying "friendly" information there on a row-by-row basis, which is comparatively very easy.