[vtkusers] updating a vtkCompositeDataPipeline

[David Feng]

I'm having trouble getting a request for data to propagate for a
vtkDataRepresentation used in a ParaView Client/Server view module
plugin.  The representation updates properly when I test in plain VTK
code, but it's not updating when it gets created in a proxy for the
plugin.  The issues I'm having seem to be coming from the
vtkCompositeDataPipeline class, which appears to be instantiated in
the context of proxies.

The problem: my data representation has no output ports, and the
vtkCompositeDataPipeline segfaults on this case in several places (for
example, line 598 assumes that the output information object is not
null).  When I added some simple null checks the segfaults stop, but
update requests are being ignored.  I'm guessing that ExecuteData
requests will only be called if there is an out-of-date output data
object.  I tried adding an output port to my representation just to
see if that would fix it, though, and it didn't.

Any suggestions would be appreciated.

Thanks,
David

-- 
http://www.cs.unc.edu/~dfeng