diff --git a/rest_framework/compat.py b/rest_framework/compat.py index 7783bced3..dacc1ac8a 100644 --- a/rest_framework/compat.py +++ b/rest_framework/compat.py @@ -139,14 +139,11 @@ except ImportError: requests = None -# Django-guardian is optional. Import only if guardian is in INSTALLED_APPS -# Fixes (#1712). We keep the try/except for the test suite. -guardian = None -try: - if 'guardian' in settings.INSTALLED_APPS: - import guardian # noqa -except ImportError: - pass +def is_guardian_installed(): + """ + django-guardian is optional and only imported if in INSTALLED_APPS. + """ + return 'guardian' in settings.INSTALLED_APPS # PATCH method is not implemented by Django diff --git a/rest_framework/filters.py b/rest_framework/filters.py index cf8f6d1f7..ab2ce68b4 100644 --- a/rest_framework/filters.py +++ b/rest_framework/filters.py @@ -16,7 +16,9 @@ from django.utils import six from django.utils.encoding import force_text from django.utils.translation import ugettext_lazy as _ -from rest_framework.compat import coreapi, coreschema, distinct, guardian +from rest_framework.compat import ( + coreapi, coreschema, distinct, is_guardian_installed +) from rest_framework.settings import api_settings @@ -282,7 +284,7 @@ class DjangoObjectPermissionsFilter(BaseFilterBackend): has read object level permissions. """ def __init__(self): - assert guardian, 'Using DjangoObjectPermissionsFilter, but django-guardian is not installed' + assert is_guardian_installed(), 'Using DjangoObjectPermissionsFilter, but django-guardian is not installed' perm_format = '%(app_label)s.view_%(model_name)s' @@ -290,6 +292,7 @@ class DjangoObjectPermissionsFilter(BaseFilterBackend): # We want to defer this import until run-time, rather than import-time. # See https://github.com/encode/django-rest-framework/issues/4608 # (Also see #1624 for why we need to make this import explicitly) + from guardian import VERSION as guardian_version from guardian.shortcuts import get_objects_for_user extra = {} @@ -300,7 +303,7 @@ class DjangoObjectPermissionsFilter(BaseFilterBackend): 'model_name': model_cls._meta.model_name } permission = self.perm_format % kwargs - if tuple(guardian.VERSION) >= (1, 3): + if tuple(guardian_version) >= (1, 3): # Maintain behavior compatibility with versions prior to 1.3 extra = {'accept_global_perms': False} else: diff --git a/tests/test_permissions.py b/tests/test_permissions.py index 3440f143e..37540eb8e 100644 --- a/tests/test_permissions.py +++ b/tests/test_permissions.py @@ -13,7 +13,7 @@ from rest_framework import ( HTTP_HEADER_ENCODING, authentication, generics, permissions, serializers, status, views ) -from rest_framework.compat import guardian +from rest_framework.compat import is_guardian_installed from rest_framework.filters import DjangoObjectPermissionsFilter from rest_framework.routers import DefaultRouter from rest_framework.test import APIRequestFactory @@ -308,7 +308,7 @@ class GetQuerysetObjectPermissionInstanceView(generics.RetrieveUpdateDestroyAPIV get_queryset_object_permissions_view = GetQuerysetObjectPermissionInstanceView.as_view() -@unittest.skipUnless(guardian, 'django-guardian not installed') +@unittest.skipUnless(is_guardian_installed(), 'django-guardian not installed') class ObjectPermissionsIntegrationTests(TestCase): """ Integration tests for the object level permissions API.