Django REST Framework：尝试获取序列化器上字段的值时发生AttributeError

Question

I'm having trouble trying to correct the following error: AttributeError at /api/v1/tasks/queue/ Got AttributeError when attempting to get a value for field start_at on serializer TaskSerializer . The serializer field might be named incorrectly and not match any attribute or key on the bytes instance. Original exception text was: 'bytes' object has no attribute 'start_at'.

The error happens when i send a request to the API tasks/queue, i'm having a 500 Internal Server Error.

I've tried several solutions presented on similar problems here on StackOverflow, including changing the field and serializer, but to no avail.

Posted below is relevant code snippets:

serializers.py

class TaskSerializer(serializers.ModelSerializer):
    start_at = serializers.DateField(format=settings.api_settings.DATE_FORMAT)

    class Meta:
        model = Task
        fields = '__all__'
        depth = 2

views.py

class TaskQueue(generics.ListCreateAPIView):
    serializer_class = TaskSerializer

    def get_queryset(self):
        queryset = Task.objects.all()
        update_histogram()
        role = self.request.query_params.get('role', None)
        user = self.request.user
        if authorization(user,1) and role in ['camp', 'prod']:
            if Task.objects.filter(status='todo', service__role=role).exclude(service__type='incident').count() <= 1:
                return Task.objects.filter(status='todo', service__role=role).exclude(service__type='incident')
            else:
                queue = queryset.filter(status='todo', previous_task__isnull=True, next_task__isnull=False, service__role=role).exclude(service__type='incident')
                node = queue
                while node.first().next_task:
                    node = Task.objects.filter(previous_task=node.first())
                    queue = queue | node
                return queue
        else:
            return HttpResponse(status=404)

The expected output is a json with the object, but instead i'm getting an error 500.

Any help would be very appreciated.

Answer 1

The TaskQueue.get_queryset method is returning an HttpResponse .

View.get_queryset when overridden must return a QuerySet and no other object.

In order to resolve an unauthorized request to a 404, return an empty QuerySet or move this check higher up using a permission class.

class TaskQueue(generics.ListCreateAPIView):
    serializer_class = TaskSerializer

    def get_queryset(self):
        # ...
        if authorization(user,1) and role in ['camp', 'prod']:
            #...
        else:
            return Task.objects.none()