NZ Farmer gave a solution how to use a control function for a customised attribute form from within your own plugin. It seems that the control function accompanying a customised UI Form needs to be a py file somewhere located (addressed with layer.setEditFormInit), but I would like it to be part of my running plugin.
NZ Farmers'solution: In the init method of your plugin: Firstly add the plugin directory to the system path list (or a subdirectory of it) Secondly, initialise a static variable with the Plugin's instance (self)
However, I cannot figure out NZ Farmer's solution, i.e. how to put that solution in Python code and where the code should be placed. Or perhaps there is a different solution. Any help?