Call ViewSet method from another view

Question

I have a mobile app with a Django REST framework API and I have a lot of ModelViewSet that I call to retrieve data. I have performance issue because I need to call a lot of routes after the user login, and I would like to keep the REST logic but also returns after the login all the viewsets content in the login response (keeping their filters).

Is it possible to call a ModelViewset list() from another view (viewset or APIView)?

The only answer I found on SO was to do something like this

class ContentGenerator(APIView):

    def get(self, request, format=None):
         data = MyModelViewSet.as_view({'get': 'list'})(request).data

         return Response({'data': data})

But it is not supported

Exception Value: The `request` argument must be an instance of `django.http.HttpRequest`, not `rest_framework.request.Request`

Is there another solution?

Answer 1

After some research, it looks like there might be side-effects to reuse the request in other views, so it is not officially supported by DRF. It is hacky, but if you know what you are doing, this is a solution.

data = MyModelViewSet.as_view({'get': 'list'})(request._request).data

Answer 2

I solved this in 2 ways. Assume I have a view A and a viewset B and that I want to call B.my_action from A. B.my_action handles a specific id e.g. user id, product id etc.

1st way

code w/in BViewSet

@action(detail=True, methods=['post'])
def my_action(self, request, pk=None):
 try:
   # works when you call from web UI, through router
   # automatically you have one specific view corresponding
   # to specific id e.g. user id, product id etc
   instance = self.get_object()
 except AttributeError as ae:
   # here you don't have a specific view instantiated
   # and you have many ids e.g. user ids, product ids etc
   # pick one id
   instance = MyModelObject.objects.get(id=pk)

 # rest of code as is, no change

code w/in e.g. AView.utils.py that calls BViewSet.my_action

Below request is the request passed to AView when AView called through web UI.

from django.http import HttpRequest

data = BViewSet(detail=True)
new_request = HttpRequest()
new_request.data = any_data_I_need_to_pass # e.g. request.data

ret = data.my_action(new_request, pk=request.data['id'])
return ret

2nd way

I decoupled my_action functionality from my_action call i.e.

code w/in BViewSet

@action(detail=True, methods=['post'])
def my_action(self, request, pk=None):
  instance = self.get_object()
  ret = my_action_server(instance, request.data)
  return Response(data=ret)

def my_action_server(instance, data):
   # all code comes here
   return result

code w/in Aview

# import my_action_server as needed
# call my_action_server
# AView should provide everything needed