[Django]-How to override the default value of a Model Field from an Abstract Base Class

by

36👍

You can actually do this as follows:

class BaseMessage(models.Model):
    is_public = models.BooleanField(default=False)
    # some more fields...

    class Meta:
        abstract = True

class Message(BaseMessage):
    # some fields...
Message._meta.get_field('is_public').default = True

I have done this once or twice. It works, because the field on Message is a different instance than the field on BaseMessage. However, I doubt it’s recommended 😉 It depends a lot on how django internals currently work, so there’s no guarantee that it will work forever.

👤melinath

0👍

For validation level overload like max_length one could add this to apps.py ready method

from django.apps import AppConfig
from django.utils.translation import gettext_lazy as _


class MyAppConfig(AppConfig):
    name = "myapp"
    verbose_name = _("myapp")

    def ready(self):
        from myapp.models import MyModel

        # HACK: to set max_length for field when you can't change
        # this on parent model for example when inheriting from third
        # party app
        MyModel._meta.get_field('field').max_length = 128
👤Sardorbek Imomaliev

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