Styjun

I'm studying django rest framework and would like the create a function. In this function, I need to pass a list in JSON and update by serializer.

For help I wrote a code example below.

Serialzer example:

class GarageViewSet(viewsets.ModelViewSet):
 queryset = Garage.objects.all()
 serializer_class = GarageSerializer
 model = Garage

class CarViewSet(RestrictedQuerysetMixin, viewsets.ModelViewSet):
 queryset = Car.objects.all()
 serializer_class = CarSerializer
 model = Car

Well. I need to update a car list through the garage serializer. I'm thinking anything like this:

(example view)

class GarageViewSet(viewsets.ModelViewSet):
 queryset = Garage.objects.all()
 serializer_class = GarageSerializer
 model = Garage

 @action(detail=True, methods=['put'])
 def update_car(self, request):
 ...
 serializer = CarSerializer(queryset, many=True)
 ...
 return Response(serializer.data)

Attempt 1:

Searching and reading the doc, I tried this way:

 @action(methods=['put'], detail=False)
 def update_car(self, request, *args, **kwargs): 
 if request.method == 'PUT':
 data = JSONParser().parse(request)
 serializer = CarSerializer(data=data, many=True)
 if serializer.is_valid():
 serializer.save()
 return JsonResponse(serializer.data)
 return JsonResponse(serializer.errors, status=400)

But I received this error:

non_field_errors:
["Expected a list of items but got type "dict"."]

Attempt 2:

With a @fxgx I tried too:

 def update_car(self, request):
 serializer = CarSerializer(data=request.data)
 serializer.is_valid(raise_exception=True)
 validated_data = dict(list(serializer.validated_data.items()))
 queryset = Car.objects.update(**validated_data)
 return Response(CarSerializer(queryset, many=True).data)

But I received this error:

 "detail": "Not found."

DRF serializers do not support bulk updates, you must pass an object instance to serializer to update it. What you can do is serializing data using serializer, updating objects with validated data and then serializing objects again to get response data:

 class GarageViewSet(viewsets.ModelViewSet):
 queryset = Garage.objects.all()
 serializer_class = GarageSerializer
 model = Garage

 @action(detail=False, methods=['put'])
 def update_car(self, request):
 ...
 # Use partial=True for partial updates.
 serializer = CarSerializer(data=request.data)

 # Validate data.
 serializer.is_valid(raise_exception=True)

 # Get validated data in dictionary format.
 validated_data = dict(list(serializer.validated_data.items()))

 # Update objects
 quertset.update(**validated_data)

 ...
 return Response(CarSerializer(queryset, many=True).data)