model Field subclass + validation

[Luke M]

Hi folks,

I asked a question on StackOverflow and I don't know if it will get any
answers because it is quite specific. I would like to subclass a
JSONField implementation to add some custom validation logic and don't
really know where to start.

I would really appreciate if anyone could help out by either answering
here or on SO.

Here is the full question text:
https://stackoverflow.com/questions/33460690/django-models-add-validation-to-custom-field

Best,
Luke