Fix KeyError exception for nested resource during generate swagger.

This patch fix bug #227

rest_framework_nested/viewsets.py

@@ -46,6 +46,9 @@ def get_queryset(self):
         """
         queryset = super(NestedViewSetMixin, self).get_queryset()
 
+        if getattr(self, 'swagger_fake_view', False):
+            return queryset
+
         orm_filters = {}
         parent_lookup_kwargs = self._get_parent_lookup_kwargs()
         for query_param, field_name in parent_lookup_kwargs.items():

tests/test_viewsets.py

@@ -9,6 +9,7 @@
 from rest_framework.serializers import HyperlinkedModelSerializer, ModelSerializer
 from rest_framework.viewsets import ModelViewSet
 from rest_framework.reverse import reverse as drf_reverse
+from rest_framework.schemas import generators
 
 from rest_framework_nested.routers import NestedSimpleRouter
 from rest_framework_nested.serializers import NestedHyperlinkedModelSerializer
@@ -210,3 +211,13 @@ def test_create_child_on_viewset_with_mixin(self):
                                  kwargs={'pk': self.root_1.pk},
                                  request=response.wsgi_request)
         self.assertEqual(data['parent'], parent_url)
+
+    def test_get_queryset_for_children_resource(self):
+        gen = generators.BaseSchemaGenerator()
+        gen._initialise_endpoints()
+        for path, method, callback in gen.endpoints:
+            view = gen.create_view(callback, method)
+            # drf_yasg set swagger_fake_view attribute for all view
+            setattr(view, 'swagger_fake_view', True)
+            # no error message should be raised here
+            view.get_queryset()