Django REST Framework: Validate before a delete

Question

I want to run a validation before an object is deleted, to prevent deletion in certain cases and return as a validation error. How do I do that? What I have currently doesn't seem right:

class CallDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = XCall.objects.all()
    serializer_class = CallSerializer
    ...

    def pre_delete(self, obj):
        if obj.survey:
            raise serializers.ValidationError("Too late to delete")

Answer 1

The solution I found was to override the destroy method on the api.

class CallDetail(generics.RetrieveUpdateDestroyAPIView):
    queryset = XCall.objects.all()
    serializer_class = CallSerializer
    ...

    def destroy(self, request, *args, **kwargs):
        obj = self.get_object()
        if obj.survey:
            return Response(data={'message': "Too late to delete"},
                            status=status.HTTP_400_BAD_REQUEST)
        self.perform_destroy(obj)
        return Response(status=status.HTTP_204_NO_CONTENT)

For me makes much more sense to validate on the destroy method instead of validating on the object permission check as avances123 mentioned, since permission should only check for permission stuffs, and doesn't return any messages related to validation.

Hope that helps ;)