[Qgis-developer] A common set of functions for QGIS plugins

[Victor Olaya]

Hi all,

We have discussed sometimes in here about the need of having some
common functions for plugin developers, to avoid all plugins having to
reimplement those functions, sometimes not in the most correct way. It
will also bring some homogeneity to plugins, which I think it is a
good thing.

With the changes that will be coming to QGIS soon, I think this is a
good idea to work on, and I have started a small project here to
create a set of Python modules with those common functions.

https://github.com/volaya/qgiscommons

Not much yet, but I plan to work on that and make it grow during this
week. With the Hackfest coming, I think it is a good time to ask other
devs to contribute...

May plan of action is as follows:

- Work on implementing a comprehensive set of functions and classes,
hopefully with the help of other devs

- Adapt Processing to use it and replace the current set of utilities
that Processing (like many plugins) has.

- Create a QEP to elevate this set of functions and classes to the
qgis.utils module, so it has more visibility and it becomes a part of
QGIS core.

Following this, I believe the next steps that we could take could be:

- Documenting this clearly in the PyCookbook, so all devs are aware of this.

- Enforcing the use of common functions and classes, and even request
it before a plugin is accepted for publishing


Since we will be transitioning to Qt5/Python3, this set of common
functions sounds also like a good place to add all kinds of utilities
that might help this migration for existing plugins.

Let me know your thoughts

Even if you cannot contribute the code of a function to the repo, feel
free to open an issue recommending functions that you consider should
be in there. I will be working on this and will implement all those
ideas if they sound interesting and useful for other people


Thanks in advance