Django Rest Framework - "detail": "Not found."

Hi when doing this request: groups/25010a31-fc5b-47c8-9c5c-d740e5743f52/members/4/ - I get "detail": "Not found"

However, if you look in the queryset I have printed the Groupmember instance and this ends up printing out that particular instance so clearly it exists?

View:

class MemberDetail(mixins.RetrieveModelMixin, mixins.DestroyModelMixin, mixins.UpdateModelMixin, generics.GenericAPIView): serializer_class = GroupMembersSerializer lookup_field = "user_id" lookup_url_kwarg = "uuid" def get_queryset(self): group = self.kwargs["uuid"] user_id = self.kwargs["user_id"] print GroupMember.objects.get(group = group, user_id = user_id) return GroupMember.objects.get(group = group, user_id = user_id) def get(self, request, *args, **kwargs): return self.retrieve(self, request, *args, **kwargs) def put(self, request, *args, **kwargs): return self.update(self, request, *args, **kwargs) def delete(self, request, *args, **kwargs): return self.destroy(self, request, *args, **kwargs) 

urls:

 urlpatterns = [ url(r'^$', views.GroupList.as_view()), url(r'^(?P<uuid>[^/]+)/$', views.GroupDetail.as_view()), url(r'^(?P<uuid>[^/]+)/members/$', views.MemberList.as_view()), url(r'^(?P<uuid>[^/]+)/members/(?P<user_id>[0-9]+)/$', views.MemberDetail.as_view()), ] 

Any help?

4 Answers

Firstly, you need to return a queryset in get_queryset() method.

Also, you have incorrectly defined lookup_url_kwarg as uuid. It should infact be user_id as this url kwarg value is used to perform lookup for uuid lookup_field in the queryset returned from the get_queryset() method.

The default value for lookup_url_kwarg if unset is the same value as lookup_field. So, we don't need to define lookup_url_kwarg even. It will be computed from lookup_field.

class MemberDetail(mixins.RetrieveModelMixin, mixins.DestroyModelMixin, mixins.UpdateModelMixin, generics.GenericAPIView): serializer_class = GroupMembersSerializer lookup_field = "user_id" # no need to define 'lookup_url_kwarg' as both have same value def get_queryset(self): group = self.kwargs["uuid"] return GroupMember.objects.filter(group = group) # return a queryset 

In the get_queryset() method, we just filter using the group and not by user_id as this will be performed by DRF itself whenever there is a retrieve request.

Using .get() on a queryset will return an object and not a queryset. To perform filtering based on the value of lookup_field, we need a queryset. Now, .filter() returns a queryset so we used that here.

Note: When you returned GroupMember.objects.filter(group = group, user_id = user_id), the retrieve tried to perform lookup on this returned queryset on the user_id field with its value as lookup_url_kwarg value i.e. user_id=25010a31-fc5b-47c8-9c5c-d740e5743f52. Since no such object exists in that queryset, it returned that error.

In my case in my routers.py file I had written it like this

router.register(r'',PersonViewSet) router.register(r'PersonEmployee',PersonEmployeeViewSet) 

so I changed it to

router.register(r'PersonEmployee',PersonEmployeeViewSet) router.register(r'',PersonViewSet) 

It was reading the empty path URL first and throwing detail not found, so I kept router with the empty path at last and it worked fine.

normally this error appears when you installed Django rest framework datatables, please check the next values on the configuration of Rest Framework on your settings:

REST_FRAMEWORK = { 'DEFAULT_AUTHENTICATION_CLASSES': ( 'rest_framework.authentication.TokenAuthentication', 'rest_framework.authentication.SessionAuthentication', ), 'DEFAULT_RENDERER_CLASSES': ( 'rest_framework.renderers.JSONRenderer', 'rest_framework.renderers.BrowsableAPIRenderer', 'rest_framework_datatables.renderers.DatatablesRenderer', ), 'DEFAULT_FILTER_BACKENDS': ( 'rest_framework_datatables.filters.DatatablesFilterBackend', ), 'DEFAULT_PAGINATION_CLASS': 'rest_framework_datatables.pagination.DatatablesPageNumberPagination', 'PAGE_SIZE': 50, 'EXCEPTION_HANDLER': 'utils.rest_framework.views.exception_handler' } 

Just wanted to add. In the case I was looking at the queryset wasn't returning a queryset with the expected object, so in terms of what the changes would look like for your question:

class MemberDetail(generics.GenericAPIView): serializer_class = GroupMembersSerializer queryset = GroupMember.objects.filter(...) 

changed to:

queryset = GroupMember.objects.all()