text: from __future__ import unicode_literals
  from django.db import models
  from django.shortcuts import get_object_or_404
  from django.test import TestCase
  from rest_framework import generics, renderers, serializers, status
  from rest_framework.test import APIRequestFactory
  from rest_framework.tests.models import BasicModel, Comment, SlugBasedModel
  from rest_framework.compat import six
  
  factory = APIRequestFactory()
  
  
  class RootView(generics.ListCreateAPIView):
      """
      Example description for OPTIONS.
      """
      model = BasicModel
  
  
  class InstanceView(generics.RetrieveUpdateDestroyAPIView):
      """
      Example description for OPTIONS.
      """
      model = BasicModel
  
      def get_queryset(self):
          queryset = super(InstanceView, self).get_queryset()
          return queryset.exclude(text='filtered out')
  
  
  class SlugSerializer(serializers.ModelSerializer):
      slug = serializers.Field()  # read only
  
      class Meta:
          model = SlugBasedModel
          exclude = ('id',)
  
  
  class SlugBasedInstanceView(InstanceView):
      """
      A model with a slug-field.
      """
      model = SlugBasedModel
      serializer_class = SlugSerializer
      lookup_field = 'slug'
  
  
  class TestRootView(TestCase):
      def setUp(self):
          """
          Create 3 BasicModel instances.
          """
          items = ['foo', 'bar', 'baz']
          for item in items:
              BasicModel(text=item).save()
          self.objects = BasicModel.objects
          self.data = [
              {'id': obj.id, 'text': obj.text}
              for obj in self.objects.all()
          ]
          self.view = RootView.as_view()
  
      def test_get_root_view(self):
          """
          GET requests to ListCreateAPIView should return list of objects.
          """
          request = factory.get('/')
          with self.assertNumQueries(1):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, self.data)
  
      def test_post_root_view(self):
          """
          POST requests to ListCreateAPIView should create a new object.
          """
          data = {'text': 'foobar'}
          request = factory.post('/', data, format='json')
          with self.assertNumQueries(1):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          self.assertEqual(response.data, {'id': 4, 'text': 'foobar'})
          created = self.objects.get(id=4)
          self.assertEqual(created.text, 'foobar')
  
      def test_put_root_view(self):
          """
          PUT requests to ListCreateAPIView should not be allowed
          """
          data = {'text': 'foobar'}
          request = factory.put('/', data, format='json')
          with self.assertNumQueries(0):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
          self.assertEqual(response.data, {"detail": "Method 'PUT' not allowed."})
  
      def test_delete_root_view(self):
          """
          DELETE requests to ListCreateAPIView should not be allowed
          """
          request = factory.delete('/')
          with self.assertNumQueries(0):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
          self.assertEqual(response.data, {"detail": "Method 'DELETE' not allowed."})
  
      def test_options_root_view(self):
          """
          OPTIONS requests to ListCreateAPIView should return metadata
          """
          request = factory.options('/')
          with self.assertNumQueries(0):
              response = self.view(request).render()
          expected = {
              'parses': [
                  'application/json',
                  'application/x-www-form-urlencoded',
                  'multipart/form-data'
              ],
              'renders': [
                  'application/json',
                  'text/html'
              ],
              'name': 'Root',
              'description': 'Example description for OPTIONS.',
              'actions': {
                  'POST': {
                      'text': {
                          'max_length': 100,
                          'read_only': False,
                          'required': True,
                          'type': 'string',
                          "label": "Text comes here",
                          "help_text": "Text description."
                      },
                      'id': {
                          'read_only': True,
                          'required': False,
                          'type': 'integer',
                          'label': 'ID',
                      },
                  }
              }
          }
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, expected)
  
      def test_post_cannot_set_id(self):
          """
          POST requests to create a new object should not be able to set the id.
          """
          data = {'id': 999, 'text': 'foobar'}
          request = factory.post('/', data, format='json')
          with self.assertNumQueries(1):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          self.assertEqual(response.data, {'id': 4, 'text': 'foobar'})
          created = self.objects.get(id=4)
          self.assertEqual(created.text, 'foobar')
  
  
  class TestInstanceView(TestCase):
      def setUp(self):
          """
          Create 3 BasicModel intances.
          """
          items = ['foo', 'bar', 'baz', 'filtered out']
          for item in items:
              BasicModel(text=item).save()
          self.objects = BasicModel.objects.exclude(text='filtered out')
          self.data = [
              {'id': obj.id, 'text': obj.text}
              for obj in self.objects.all()
          ]
          self.view = InstanceView.as_view()
          self.slug_based_view = SlugBasedInstanceView.as_view()
  
      def test_get_instance_view(self):
          """
          GET requests to RetrieveUpdateDestroyAPIView should return a single object.
          """
          request = factory.get('/1')
          with self.assertNumQueries(1):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, self.data[0])
  
      def test_post_instance_view(self):
          """
          POST requests to RetrieveUpdateDestroyAPIView should not be allowed
          """
          data = {'text': 'foobar'}
          request = factory.post('/', data, format='json')
          with self.assertNumQueries(0):
              response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_405_METHOD_NOT_ALLOWED)
          self.assertEqual(response.data, {"detail": "Method 'POST' not allowed."})
  
      def test_put_instance_view(self):
          """
          PUT requests to RetrieveUpdateDestroyAPIView should update an object.
          """
          data = {'text': 'foobar'}
          request = factory.put('/1', data, format='json')
          with self.assertNumQueries(2):
              response = self.view(request, pk='1').render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, {'id': 1, 'text': 'foobar'})
          updated = self.objects.get(id=1)
          self.assertEqual(updated.text, 'foobar')
  
      def test_patch_instance_view(self):
          """
          PATCH requests to RetrieveUpdateDestroyAPIView should update an object.
          """
          data = {'text': 'foobar'}
          request = factory.patch('/1', data, format='json')
  
          with self.assertNumQueries(2):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, {'id': 1, 'text': 'foobar'})
          updated = self.objects.get(id=1)
          self.assertEqual(updated.text, 'foobar')
  
      def test_delete_instance_view(self):
          """
          DELETE requests to RetrieveUpdateDestroyAPIView should delete an object.
          """
          request = factory.delete('/1')
          with self.assertNumQueries(2):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_204_NO_CONTENT)
          self.assertEqual(response.content, six.b(''))
          ids = [obj.id for obj in self.objects.all()]
          self.assertEqual(ids, [2, 3])
  
      def test_options_instance_view(self):
          """
          OPTIONS requests to RetrieveUpdateDestroyAPIView should return metadata
          """
          request = factory.options('/1')
          with self.assertNumQueries(1):
              response = self.view(request, pk=1).render()
          expected = {
              'parses': [
                  'application/json',
                  'application/x-www-form-urlencoded',
                  'multipart/form-data'
              ],
              'renders': [
                  'application/json',
                  'text/html'
              ],
              'name': 'Instance',
              'description': 'Example description for OPTIONS.',
              'actions': {
                  'PUT': {
                      'text': {
                          'max_length': 100,
                          'read_only': False,
                          'required': True,
                          'type': 'string',
                          'label': 'Text comes here',
                          'help_text': 'Text description.'
                      },
                      'id': {
                          'read_only': True,
                          'required': False,
                          'type': 'integer',
                          'label': 'ID',
                      },
                  }
              }
          }
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, expected)
  
      def test_options_before_instance_create(self):
          """
          OPTIONS requests to RetrieveUpdateDestroyAPIView should return metadata
          before the instance has been created
          """
          request = factory.options('/999')
          with self.assertNumQueries(1):
              response = self.view(request, pk=999).render()
          expected = {
              'parses': [
                  'application/json',
                  'application/x-www-form-urlencoded',
                  'multipart/form-data'
              ],
              'renders': [
                  'application/json',
                  'text/html'
              ],
              'name': 'Instance',
              'description': 'Example description for OPTIONS.',
              'actions': {
                  'PUT': {
                      'text': {
                          'max_length': 100,
                          'read_only': False,
                          'required': True,
                          'type': 'string',
                          'label': 'Text comes here',
                          'help_text': 'Text description.'
                      },
                      'id': {
                          'read_only': True,
                          'required': False,
                          'type': 'integer',
                          'label': 'ID',
                      },
                  }
              }
          }
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, expected)
  
      def test_get_instance_view_incorrect_arg(self):
          """
          GET requests with an incorrect pk type, should raise 404, not 500.
          Regression test for #890.
          """
          request = factory.get('/a')
          with self.assertNumQueries(0):
              response = self.view(request, pk='a').render()
          self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
  
      def test_put_cannot_set_id(self):
          """
          PUT requests to create a new object should not be able to set the id.
          """
          data = {'id': 999, 'text': 'foobar'}
          request = factory.put('/1', data, format='json')
          with self.assertNumQueries(2):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, {'id': 1, 'text': 'foobar'})
          updated = self.objects.get(id=1)
          self.assertEqual(updated.text, 'foobar')
  
      def test_put_to_deleted_instance(self):
          """
          PUT requests to RetrieveUpdateDestroyAPIView should create an object
          if it does not currently exist.
          """
          self.objects.get(id=1).delete()
          data = {'text': 'foobar'}
          request = factory.put('/1', data, format='json')
          with self.assertNumQueries(3):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          self.assertEqual(response.data, {'id': 1, 'text': 'foobar'})
          updated = self.objects.get(id=1)
          self.assertEqual(updated.text, 'foobar')
  
      def test_put_to_filtered_out_instance(self):
          """
          PUT requests to an URL of instance which is filtered out should not be
          able to create new objects.
          """
          data = {'text': 'foo'}
          filtered_out_pk = BasicModel.objects.filter(text='filtered out')[0].pk
          request = factory.put('/{0}'.format(filtered_out_pk), data, format='json')
          response = self.view(request, pk=filtered_out_pk).render()
          self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
  
      def test_put_as_create_on_id_based_url(self):
          """
          PUT requests to RetrieveUpdateDestroyAPIView should create an object
          at the requested url if it doesn't exist.
          """
          data = {'text': 'foobar'}
          # pk fields can not be created on demand, only the database can set the pk for a new object
          request = factory.put('/5', data, format='json')
          with self.assertNumQueries(3):
              response = self.view(request, pk=5).render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          new_obj = self.objects.get(pk=5)
          self.assertEqual(new_obj.text, 'foobar')
  
      def test_put_as_create_on_slug_based_url(self):
          """
          PUT requests to RetrieveUpdateDestroyAPIView should create an object
          at the requested url if possible, else return HTTP_403_FORBIDDEN error-response.
          """
          data = {'text': 'foobar'}
          request = factory.put('/test_slug', data, format='json')
          with self.assertNumQueries(2):
              response = self.slug_based_view(request, slug='test_slug').render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          self.assertEqual(response.data, {'slug': 'test_slug', 'text': 'foobar'})
          new_obj = SlugBasedModel.objects.get(slug='test_slug')
          self.assertEqual(new_obj.text, 'foobar')
  
      def test_patch_cannot_create_an_object(self):
          """
          PATCH requests should not be able to create objects.
          """
          data = {'text': 'foobar'}
          request = factory.patch('/999', data, format='json')
          with self.assertNumQueries(1):
              response = self.view(request, pk=999).render()
          self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
          self.assertFalse(self.objects.filter(id=999).exists())
  
  
  class TestOverriddenGetObject(TestCase):
      """
      Test cases for a RetrieveUpdateDestroyAPIView that does NOT use the
      queryset/model mechanism but instead overrides get_object()
      """
      def setUp(self):
          """
          Create 3 BasicModel intances.
          """
          items = ['foo', 'bar', 'baz']
          for item in items:
              BasicModel(text=item).save()
          self.objects = BasicModel.objects
          self.data = [
              {'id': obj.id, 'text': obj.text}
              for obj in self.objects.all()
          ]
  
          class OverriddenGetObjectView(generics.RetrieveUpdateDestroyAPIView):
              """
              Example detail view for override of get_object().
              """
              model = BasicModel
  
              def get_object(self):
                  pk = int(self.kwargs['pk'])
                  return get_object_or_404(BasicModel.objects.all(), id=pk)
  
          self.view = OverriddenGetObjectView.as_view()
  
      def test_overridden_get_object_view(self):
          """
          GET requests to RetrieveUpdateDestroyAPIView should return a single object.
          """
          request = factory.get('/1')
          with self.assertNumQueries(1):
              response = self.view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, self.data[0])
  
  
  # Regression test for #285
  
  class CommentSerializer(serializers.ModelSerializer):
      class Meta:
          model = Comment
          exclude = ('created',)
  
  
  class CommentView(generics.ListCreateAPIView):
      serializer_class = CommentSerializer
      model = Comment
  
  
  class TestCreateModelWithAutoNowAddField(TestCase):
      def setUp(self):
          self.objects = Comment.objects
          self.view = CommentView.as_view()
  
      def test_create_model_with_auto_now_add_field(self):
          """
          Regression test for #285
  
          https://github.com/tomchristie/django-rest-framework/issues/285
          """
          data = {'email': 'foobar@example.com', 'content': 'foobar'}
          request = factory.post('/', data, format='json')
          response = self.view(request).render()
          self.assertEqual(response.status_code, status.HTTP_201_CREATED)
          created = self.objects.get(id=1)
          self.assertEqual(created.content, 'foobar')
  
  
  # Test for particularly ugly regression with m2m in browsable API
  class ClassB(models.Model):
      name = models.CharField(max_length=255)
  
  
  class ClassA(models.Model):
      name = models.CharField(max_length=255)
      childs = models.ManyToManyField(ClassB, blank=True, null=True)
  
  
  class ClassASerializer(serializers.ModelSerializer):
      childs = serializers.PrimaryKeyRelatedField(many=True, source='childs')
  
      class Meta:
          model = ClassA
  
  
  class ExampleView(generics.ListCreateAPIView):
      serializer_class = ClassASerializer
      model = ClassA
  
  
  class TestM2MBrowseableAPI(TestCase):
      def test_m2m_in_browseable_api(self):
          """
          Test for particularly ugly regression with m2m in browsable API
          """
          request = factory.get('/', HTTP_ACCEPT='text/html')
          view = ExampleView().as_view()
          response = view(request).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
  
  
  class InclusiveFilterBackend(object):
      def filter_queryset(self, request, queryset, view):
          return queryset.filter(text='foo')
  
  
  class ExclusiveFilterBackend(object):
      def filter_queryset(self, request, queryset, view):
          return queryset.filter(text='other')
  
  
  class TwoFieldModel(models.Model):
      field_a = models.CharField(max_length=100)
      field_b = models.CharField(max_length=100)
  
  
  class DynamicSerializerView(generics.ListCreateAPIView):
      model = TwoFieldModel
      renderer_classes = (renderers.BrowsableAPIRenderer, renderers.JSONRenderer)
  
      def get_serializer_class(self):
          if self.request.method == 'POST':
              class DynamicSerializer(serializers.ModelSerializer):
                  class Meta:
                      model = TwoFieldModel
                      fields = ('field_b',)
              return DynamicSerializer
          return super(DynamicSerializerView, self).get_serializer_class()
  
  
  class TestFilterBackendAppliedToViews(TestCase):
  
      def setUp(self):
          """
          Create 3 BasicModel instances to filter on.
          """
          items = ['foo', 'bar', 'baz']
          for item in items:
              BasicModel(text=item).save()
          self.objects = BasicModel.objects
          self.data = [
              {'id': obj.id, 'text': obj.text}
              for obj in self.objects.all()
          ]
  
      def test_get_root_view_filters_by_name_with_filter_backend(self):
          """
          GET requests to ListCreateAPIView should return filtered list.
          """
          root_view = RootView.as_view(filter_backends=(InclusiveFilterBackend,))
          request = factory.get('/')
          response = root_view(request).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(len(response.data), 1)
          self.assertEqual(response.data, [{'id': 1, 'text': 'foo'}])
  
      def test_get_root_view_filters_out_all_models_with_exclusive_filter_backend(self):
          """
          GET requests to ListCreateAPIView should return empty list when all models are filtered out.
          """
          root_view = RootView.as_view(filter_backends=(ExclusiveFilterBackend,))
          request = factory.get('/')
          response = root_view(request).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, [])
  
      def test_get_instance_view_filters_out_name_with_filter_backend(self):
          """
          GET requests to RetrieveUpdateDestroyAPIView should raise 404 when model filtered out.
          """
          instance_view = InstanceView.as_view(filter_backends=(ExclusiveFilterBackend,))
          request = factory.get('/1')
          response = instance_view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
          self.assertEqual(response.data, {'detail': 'Not found'})
  
      def test_get_instance_view_will_return_single_object_when_filter_does_not_exclude_it(self):
          """
          GET requests to RetrieveUpdateDestroyAPIView should return a single object when not excluded
          """
          instance_view = InstanceView.as_view(filter_backends=(InclusiveFilterBackend,))
          request = factory.get('/1')
          response = instance_view(request, pk=1).render()
          self.assertEqual(response.status_code, status.HTTP_200_OK)
          self.assertEqual(response.data, {'id': 1, 'text': 'foo'})
  
      def test_dynamic_serializer_form_in_browsable_api(self):
          """
          GET requests to ListCreateAPIView should return filtered list.
          """
          view = DynamicSerializerView.as_view()
          request = factory.get('/')
          response = view(request).render()
          self.assertContains(response, 'field_b')
          self.assertNotContains(response, 'field_a')
  