Stop Django from creating migrations if the list of choices of a field changes

Question

I have a django core app called "foocore".

There are several optional pluging-like apps. For example "superfoo".

In my case every plugin adds a new choice in a model CharField which belongs to "foocore".

Django migrations detect changes if the list of choices get changed.

I think this is not necessary. At least one other developer thinks the same:

https://code.djangoproject.com/ticket/22837

class ActivePlugin(models.Model):
    plugin_name = models.CharField(max_length=32, choices=get_active_plugins())

The code to get the choices:

class get_active_plugins(object):
    def __iter__(self):
        for item in ....:
            yield item

The core "foocore" gets used in several projects and every installation has a different set of plugins. Django tries to create useless migrations ....

Is there a way to work around this?

Answer 1

See this bug report and discussion for more info: https://code.djangoproject.com/ticket/22837

The proposed solution was to use a callable as the argument for choices, but it appears this has not been executed for fields but for forms only.

If you really need dynamic choices than a ForeignKey is the best solution.

An alternative solution can be to add the requirement through a custom clean method for the field and/or creating a custom form. Form fields do support callable choices.

See this answer for more info: https://stackoverflow.com/a/33514551/54017