Add a Django Rest Framework mixin for a GenericViewSet to replace create with an update_or_create method

update_create_mixin.py

from django.core.exceptions import ObjectDoesNotExist
from rest_framework import status
from rest_framework.mixins import CreateModelMixin
from rest_framework.response import Response


class UpdateOrCreateModelMixin(CreateModelMixin):
    """
    Update or create a model instance.
    """

    def create(self, request, *args, **kwargs):
        try:
            instance = self.get_or_update_object(request)
            serializer = self.get_serializer(instance, data=request.data)
            response_status = status.HTTP_200_OK
        except ObjectDoesNotExist:
            serializer = self.get_serializer(data=request.data)
            response_status = status.HTTP_201_CREATED
        serializer.is_valid(raise_exception=True)
        self.perform_create(serializer)
        headers = self.get_success_headers(serializer.data)
        return Response(serializer.data, status=response_status, headers=headers)



# Usage example
class ResponseView(
    mixins.ListModelMixin, UpdateOrCreateModelMixin, viewsets.GenericViewSet
):
    serializer_class = ResponseSerializer
    queryset = Response.objects.all()

    def get_or_update_object(self, request):
        return self.get_queryset().get(
            participation_id=request.data.get("participation_id"),
            question_id=request.data.get("question_id"),
        )