Django REST framework: Check user is in group

The sensible way to parameterize permission classes is to put the parameters on the view class. That’ll let you change the behaviour from view to view.

Here’s an example:

# permissions.py
from django.contrib.auth.models import Group
from rest_framework import permissions

def is_in_group(user, group_name):
    """
    Takes a user and a group name, and returns `True` if the user is in that group.
    """
    try:
        return Group.objects.get(name=group_name).user_set.filter(id=user.id).exists()
    except Group.DoesNotExist:
        return None

class HasGroupPermission(permissions.BasePermission):
    """
    Ensure user is in required groups.
    """

    def has_permission(self, request, view):
        # Get a mapping of methods -> required group.
        required_groups_mapping = getattr(view, "required_groups", {})

        # Determine the required groups for this particular request method.
        required_groups = required_groups_mapping.get(request.method, [])

        # Return True if the user has all the required groups or is staff.
        return all([is_in_group(request.user, group_name) if group_name != "__all__" else True for group_name in required_groups]) or (request.user and request.user.is_staff)

You could then use the HasGroupPermission class like so:

# views.py
class MyView(APIView):
     permission_classes = [HasGroupPermission]
     required_groups = {
         'GET': ['moderators', 'members'],
         'POST': ['moderators', 'someMadeUpGroup'],
         'PUT': ['__all__'],
     }

     ...