Getting ready

For this recipe to work, you will need to have the contenttypes app installed. It should be in the INSTALLED_APPS list in the settings, by default, as shown in the following code:

# myproject/settings/_base.py

INSTALLED_APPS = [
    # contributed
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.staticfiles",
    # third-party
    # ...
    # local
    "myproject.apps.core",
    "myproject.apps.categories",
    "myproject.apps.ideas",
]

Again, make sure that you have already created the myproject.apps.core app for your model mixins.