Set model field choices attribute at run time?

Question

Is there any easy way to do so?

Answer 1

You can set the choices attribute to any iterable: http://docs.djangoproject.com/en/dev/ref/models/fields/#django.db.models.Field.choices

I haven't tested this myself so I'm not sure when the choices attribute is actually evaluated, but you may be able to assign a generator function that would calculate your desired choices.

You might also investigate using the Model post_init signal: http://docs.djangoproject.com/en/1.1/ref/signals/#post-init

This will give you access to your model after Django has initialized it and so you could set the choices at that time. You'd probably want to go through the "_meta" interface like so:

instance._meta.get_field_by_name('FIELD_NAME')[0].choices = [<choices>...]

Answer 2

Set the choices in __init__().