How to use Pagination in a Non-Generic View/Viewset?

Question

Prologue:

I have seen this question arising in more than one posts:

• Django Rest Framework - APIView Pagination
• Pagination not working in DRF APIView
• Django rest framework global pagination parameters not working for ModelViewSet

and can also be applied here:

• Combine ListModelMixin with APIView to show pagination

I have composed an example on SO Documentation to unify my answers in the above questions but since the Documentation will get shutdown on August 8 2017, I will follow the suggestion of this widely upvoted and discussed meta answer and transform my example to a self-answered post.

Of course I would be more than happy to see any different approach as well!!

---

Question:

I want to use a Non Generic View/Viewset (eg: APIView) on a Django Rest Framework project.
As I read on the pagination documentation:

Pagination is only performed automatically if you're using the generic views or viewsets. If you're using a regular APIView, you'll need to call into the pagination API yourself to ensure you return a paginated response. See the source code for the mixins.ListModelMixin and generics.GenericAPIView classes for an example.

Can I still continue using a non generic view/viewset?
How can I implement pagination on it?

Answer 1

We can find a solution without the need to reinvent the wheel:

1. Let's have a look on how the generics pagination is implemented: django-rest-framework/rest_framework/generics.py.
   That is exactly what we are going to use to our view as well!

2. Let's assume that we have a global pagination setup like the following in:
   settings.py:

   REST_FRAMEWORK = {
       'DEFAULT_PAGINATION_CLASS': 
           'rest_framework.pagination.DESIRED_PAGINATION_STYLE',
       'PAGE_SIZE': 100
   }
   

3. In order not to bloat our view/viewset's code, we can create a custom mixin to store our pagination code:

   class MyPaginationMixin(object):
   
       @property
       def paginator(self):
           """
           The paginator instance associated with the view, or `None`.
           """
            if not hasattr(self, '_paginator'):
                if self.pagination_class is None:
                    self._paginator = None
                else:
                    self._paginator = self.pagination_class()
            return self._paginator
   
        def paginate_queryset(self, queryset):
            """
            Return a single page of results, or `None` if pagination 
            is disabled.
            """
            if self.paginator is None:
                return None
            return self.paginator.paginate_queryset(
                queryset, self.request, view=self)
   
        def get_paginated_response(self, data):
            """
            Return a paginated style `Response` object for the given 
            output data.
            """
            assert self.paginator is not None
            return self.paginator.get_paginated_response(data)
   

4. Then on views.py:

   from rest_framework.settings import api_settings
   from rest_framework.views import APIView
   
   from my_app.mixins import MyPaginationMixin
   
   class MyView(APIView, MyPaginationMixin):
       queryset = OurModel.objects.all()
       serializer_class = OurModelSerializer
       pagination_class = api_settings.DEFAULT_PAGINATION_CLASS 
   
       # We need to override the get method to insert pagination
       def get(self, request):
           ...
           page = self.paginate_queryset(self.queryset)
           if page is not None:
               serializer = self.serializer_class(page, many=True)
               return self.get_paginated_response(serializer.data)
   

And now we have an APIView with pagination.