Django, updating DB column, rest_framework - django

Question

A bit stuck at updating column in DB. I am sending put request to update a column. But an error returns.
assert isinstance(response, HttpResponseBase), ( AssertionError:
Expected a Response, HttpResponse or HttpStreamingResponse to be
returned from the view, but received a <class 'NoneType'>
here is the front end. sending request.
updateInvoceProject(id, company_name){
return axios.put(API_HANDLER.database_api + "api/v1/update-project", {id, company_name})
},
serializer.py
class InvocesSerializer(serializers.ModelSerializer):
class Meta:
model = Invoces
fields = ("__all__")
view
#csrf_exempt
#api_view(["PUT"])
def update(request):
if request.method == "PUT":
serializer = InvocesSerializer(data=request.data)
if serializer.is_valid():
invoce = Invoces.objects.get(id=serializer.data["id"])
invoce.company_name = serializer.data["company_name"]
invoce.save()
return Response(serializer.data)
urls
urlpatterns = [
#
path("api/v1/update-project", invocesView.update, name="update-project"),
#
]
But in the end, the error I mentioned above is popping. Am I missing something here?

Answer 1

This happens because you are not returning anything when the serialized data is not valid.
you can simply make it like this, to make sure that it is going to return something in all cases.
#csrf_exempt
#api_view(["PUT"])
def update(request):
# if request.method == "PUT":
# You don't have to check for method, since you already defined it
# in api_view(...) decorator.
serializer = InvocesSerializer(data=request.data)
# Raises a ValidatinException which will be sent as a 400 response.
serializer.is_valid(raise_exception=True)
invoce = Invoces.objects.get(id=serializer.data["id"])
invoce.company_name = serializer.data["company_name"]
invoce.save()
return Response(serializer.data)
Better Solution
I suggest that you use DRF's UpdateAPIView (Do it the DRF way :D), in order to avoid getting into such errors, and also to avoid doing all the validation, and serialization by hand.
like the following:
1. Keep your InvocesSerializer, and create another one just for Updating company_name
# Inside serializers.py
class InvocesCompanyNameUpdateSerializer(serializers.ModelSerializer):
def to_representation(self, instance):
return InvocesSerializer(instance).to_representation(instance)
class Meta:
model = Invoces
fields = ('company_name',)
2 . Create an UpdateAPIView class for that serializer
# Inside views.py
class InvoiceUpdateCompanyNameAPIView(UpdateAPIView):
http_method_names = ['put'] # This is only to allow PUT method on this view.
serializer_class = InvocesCompanyNameUpdateSerializer
queryset = Invoces.objects.all()
3 . Now append that view with a re_path to your urls.
# Inside urls.py
urlpatterns = [
#
# you have to add "pk" url path variable, so DRF use it internally to identify
# which object you want to update.
re_path(r"api/v1/update-project/(?P<pk>[\d]+)/",
invocesView.InvoiceUpdateCompanyNameAPIView.as_view(),
name="update-project"),
#
]