如何在Django REST Framework中返回自定义JSON

Question

我试图返回自定义json get_queryset但总是得到404 error回应.

class TestViewSet(viewsets.ModelViewSet):
    """
    API endpoint that allows groups to be viewed or edited.
    """
    queryset = Test.objects.all()
    serializer_class = TestSerializer

    def get_queryset(self):
        if self.request.method == "GET":
            content = {'user_count': '2'}
            return HttpResponse(json.dumps(content), content_type='application/json')

如果我删除所有内容,def我会用标准的json数据得到正确的响应.我做错了什么？

Answer 1

如果您不需要ModelViewSet并且只想在GET请求上使用自定义JSON

您也可以使用APIView不需要模型的

class MyOwnView(APIView):
    def get(self, request):
        return Response({'some': 'data'})

和

urlpatterns = [
    url(r'^my-own-view/$', MyOwnView.as_view()),
]

使用ModelViewSet

您已将自定义JSON放入get_queryset,这是错误的.如果你想使用a ModelViewSet,这本身就足够了:

class TestViewSet(viewsets.ModelViewSet):
    queryset = Test.objects.all()
    serializer_class = TestSerializer

这种ModelViewSet带有默认实现.list(),.retrieve(),.create(),.update(),和.destroy().您可以根据需要覆盖(自定义)

从.retrieve()和/或 .list()中返回自定义JSONModelViewSet

例如,.retrieve()在检索单个对象时覆盖以返回自定义视图.我们可以看一下默认实现,如下所示:

def retrieve(self, request, *args, **kwargs):
    instance = self.get_object()
    serializer = self.get_serializer(instance)
    return Response(serializer.data)

以此作为返回自定义JSON的示例:

class TestViewSet(viewsets.ModelViewSet):
    queryset = Test.objects.all()
    serializer_class = TestSerializer

    def retrieve(self, request, *args, **kwargs):
        return Response({'something': 'my custom JSON'})

    def list(self, request, *args, **kwargs):
        return Response({'something': 'my custom JSON'})

Answer 2

有两种方法可以使用ModelViewSet在基于类的视图中自定义响应

解决方案1：在views.py中自定义

class StoryViewSet(viewsets.ModelViewSet):
    permission_classes = (permissions.AllowAny,)
    queryset = Story.objects.all()
    serializer_class = StorySerializer

    def retrieve(self, request, *args, **kwargs):
        # ret = super(StoryViewSet, self).retrieve(request)
        return Response({'key': 'single value'})

    def list(self, request, *args, **kwargs):
        # ret = super(StoryViewSet, self).list(request)
        return Response({'key': 'list value'})

解决方案2：在serializers.py中 自定义（我推荐这个解决方案）

class StorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Story
        fields = "__all__"

    def to_representation(self, instance):
        ret = super(StorySerializer, self).to_representation(instance)
        # check the request is list view or detail view
        is_list_view = isinstance(self.instance, list)
        extra_ret = {'key': 'list value'} if is_list_view else {'key': 'single value'}
        ret.update(extra_ret)
        return ret