Custom Group Model

Added in 2.6

Django does not provide the same ability to create a custom auth.Group model as the AbstractUser model and probably never will: https://code.djangoproject.com/ticket/29748.

To use guardian with a custom group model as it is done with a custom user model (see custom-user-model), a custom GroupObjectPermission model can be used.

Here is an example of using a custom group model with guardian:

from django.contrib.auth.models import PermissionsMixin

class CustomGroupPermissionsMixin(PermissionsMixin):
    groups = models.ManyToManyField(
        "CustomGroup",
        verbose_name=_("groups"),
        blank=True,
        help_text=_(
            "The groups this user belongs to. A user will get all permissions "
            "granted to each of their groups."
        ),
        related_name="user_set",
        related_query_name="user",
    )

    class Meta(PermissionsMixin.Meta):
        abstract = True

This mixin will be used to override the groups field of the custom user model with a field that uses the custom group model. It can be placed in myapp/mixins.py.

Then, the custom user model and the custom group model can be defined as follows:

from .mixins import CustomGroupPermissionsMixin
from guardian.mixins import GuardianUserMixin, GuardianGroupMixin

class CustomGroup(Group, GuardianGroupMixin):
    foo = models.CharField(max_length=120)  # adds a custom field to the original Group model


class User(AbstractBaseUser, CustomGroupPermissionsMixin, GuardianUserMixin):
    email = models.EmailField(
        verbose_name=_("email address"), max_length=200, unique=True, db_index=True
    )
    ...


class CustomGroupObjectPermission(GroupObjectPermissionAbstract):
    group = models.ForeignKey(CustomGroup, on_delete=models.CASCADE)

    class Meta(GroupObjectPermissionAbstract.Meta):
        abstract = False

These models can be placed in myapp/models.py. The CustomGroupObjectPermission will use the custom group model instead of the default auth.Group model.

To access the CustomGroupObjectPermission model, the function get_group_obj_perms_model can be used:

from guardian.utils import get_group_obj_perms_model

GroupObjectPermission = get_group_obj_perms_model()  # this returns the correct group permission model

def return_all_group_obj_perms():
    return GroupObjectPermission.objects.all()

Important

When using an custom GroupObjectPermission model, do not import the GroupObjectPermission model directly in your code, always use the get_group_obj_perms_model function.

By default, django-guardian monkey patches the group model to add some necessary functionality. This can result in errors if guardian is imported into the models.py of the same app where the custom group model lives.

To fix this, it is recommended to add the setting GUARDIAN_MONKEY_PATCH_GROUP = False in your settings.py and subclass guardian.mixins.GuardianGroupMixin in your custom group model.

The settings.py file for the example above would look like this:

...
GUARDIAN_MONKEY_PATCH_USER = False
GUARDIAN_MONKEY_PATCH_GROUP = False
GUARDIAN_GROUP_OBJ_PERMS_MODEL = 'myapp.CustomGroupObjectPermission'
...