How to use Pagination in a Non-Generic View/Viewse

2019-01-12 07:21发布

Prologue:

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

and can also be applied here:

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?

1条回答
迷人小祖宗
2楼-- · 2019-01-12 07:56

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.

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