Adding support for permissions based access control

drf_roles/mixins.py

@@ -1,8 +1,12 @@
 from django.conf import settings
-from django.contrib.auth.models import Group
+from django.contrib.auth.models import Group, Permission
 
 # Default settings
 DEFAULT_GROUPS = [group.name.lower() for group in Group.objects.all()]
+DEFAULT_PERMISSIONS = [
+    permission.codename.lower() for permission in Permission.objects.all()
+]
+
 DEFAULT_REGISTRY = (
     "get_queryset",
     "get_serializer_class",
@@ -42,6 +46,36 @@ def _get_role(self, user):
         else:
             return user_role.pop()
 
+
+class PermissionViewSetMixin(object):
+    """A ViewSet mixin that parameterizes DRF methods over permissions."""
+    _viewset_method_registry = set(getattr(settings, "VIEWSET_METHOD_REGISTRY", DEFAULT_REGISTRY))
+    _permissions = DEFAULT_PERMISSIONS
+
+    def __init__(self, *args, **kwargs):
+        for permission in self._permissions:
+            for fn in self._viewset_method_registry:
+                register_permission_fn(permission, fn)
+
+    def _call_permission_fn(self, fn, permission, *args, **kwargs):
+        """Attempts to call a permission-scoped method"""
+        try:
+            if not self.request.user.has_perm(permission):
+                raise RoleError("The user does not have the required permission")
+            permission_fn = "{}_for_{}".format(fn, permission)
+            return getattr(self, permission_fn)(*args, **kwargs)
+        except (AttributeError, RoleError):
+            return getattr(super(PermissionViewSetMixin, self), fn)(*args, **kwargs)
+
+
+def register_permission_fn(permission, fn):
+    """Dynamically adds fn to PermissionViewSetMixin.
+    """
+    def inner(self, *args, **kwargs):
+        return self._call_permission_fn(fn, permission, *args, **kwargs)
+    setattr(PermissionViewSetMixin, fn, inner)
+
+
 def register_fn(fn):
     """Dynamically adds fn to RoleViewSetMixin"""
     def inner(self, *args, **kwargs):

setup.py

@@ -9,7 +9,7 @@
 
 setup(
     name='django-rest-framework-roles',
-    version='0.5',
+    version='0.6',
     packages=['drf_roles'],
     include_package_data=True,
     license='BSD License',