What is "swappable" in model meta for?

django django-models django-users django-settings
frnhr picture frnhr · Feb 25, 2014 · Viewed 8.7k times · Source

Looking tough django auth models code, I came across this bit of code:

class User(AbstractUser):
    class Meta(AbstractUser.Meta):
        swappable = 'AUTH_USER_MODEL'

It's obvious that it has something to do with the new AUTH_USER_MODEL setting in settings.py, but how does it actually work, by what python "trick"?

And in what other situations can it be used?

Answer

Sarah Messer picture Sarah Messer · Jul 23, 2014

swappable is an "intentionally undocumented" feature which is currently under development / in-test. It's used to handle "I have a base abstract model which has some foreign-key relationships." Slightly more detail is available from Django's ticketing system and github. Because it's a "stealth alpha" feature, it's not guaranteed to work (for anything other than User), and understanding the detailed operation will likely require diving into source code. It works with AUTH_USER_MODEL because the User model and swappable flag were developed together, specifically for each other.

Related questions

Extending the User model with custom fields in Django

What's the best way to extend the User model (bundled with Django's authentication app) with custom fields? I would also possibly like to use the email as the username (for authentication purposes). I've already seen a few ways to do …

Read More
Django: Hide button in template, if user is not super-user

How do you get your template/view to recognize whether or not a logged in user is a super user or not? There are certain buttons on my forms (in the template) that I want completely hidden if the user …

Read More
Django custom user model and usermanager

i'm building a web application with Django 1.5. I'm using a custom User model with a custom UserManager. I followed the instructions and examples of the official Django documentation. Now, when i'm trying to create a new user via UserManager.create_…

Read More