[Qgis-user] Building an input form with choice-dependent dropdown lists

[Jeffrey Durrence]

Hi,

I have created an input form using the Drag and Drop designer,  The form has multiple dropdown widgets that are either "value map" or "value relation" widgets.   To minimize input errors, I need to make a form whose dropdrowns are completed in a certain order and whose dropdown values are based on the preceding choices.  From what I have read, it appears that this is where I would need to venture into customization with QT designer and/or python init scripts.  Having read through several examples of form customization and Python scripts, I have spent more time on clever ways of achieving similar functionality with data tricks (e.g., attaching multiple times to the same table or views derived from the same table and employing filtering on each), but I have created what appears to be an overly complicated solution.

If QT designer + python scripting holds the most promise, I'd appreciate advice on a good "entry point" for learning these techniques.  I have a located a few texts on QGIS development, but I don't know if they are the best for what I'm trying to do.  Also, if there are other mailing lists or groups that might help me, I'd welcome that input as well.

Thanks!

-- 
Jeffrey Durrence
McLean Engineering Company
jeffrey.durrence at mcleanengineering.com