AW: [Qgis-developer] python geoprocessing trouble

[Paolo Cavallini]

Düster Horst ha scritto:
> Paolo
> 
>>makeDifference
>>  if fet.geometry().wkbSize() > 0:
>>AttributeError: 'NoneType' object has no attribute 'wkbSize'
> 
> Please send the data you tried to process to me. Which type of data you 
> are work with? Shape, PostGIS, GML .... Does the error arises at all 
> geoporcessing methods?
> 
> Sometimes the mentioned error occours when the input data are non valid 
> or GEOS produces non valid geometries during the geoprocessing process. 
> The best for me is to test with the origonal data.
> 
> Regards
> Horst

Sorry Horst for not having repied sooner: I was busy with the course 
full day.
The problem happened only to a few users on some files, so it may well 
be related to topological errors in specific files.
I have asked the students to send me the files, but I cannot guarantee 
they will do it.
If it is a serious error, it will appear again. In the meantime, perhaps 
better to trap it and send the user a more meaningful message like 
"Possibly your input file has topological errors - try to check and send 
a sample (small) failing file to xxx at xxx.xxx"?
All the best.
pc