结合ListModelMixin和APIView来显示分页

Question

我想在我的API中显示分页功能，并且我正在将APIView与多个序列化程序一起使用。
我知道用ListView显示分页非常容易。
我在某个地方见过组合ListModelMixin和{}可以工作，但是如果我的代码如下：

class ListModelMixin(object):
    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())
        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)
        serializer = self.get_serializer(queryset, many=True)
        return Response(serilaizer.data)

class ItemsAPIView(APIView):
    permission_classes = (permissions.IsAuthenticated,)
    pagination_class = api_settings.DEFAULT_PAGINATION_CLASS

    def get(self, request, format=None):
        """
        Return a list of all devices of this user.
        """
        reply = {}
        try:
            products = BaseItem.objects.owned_items().filter(owner=request.user)
            reply['data'] = OwnedItemSerializer(products, many=True).data

            items = BaseItem.objects.dev_items().filter(owner=request.user)
            reply['data'].extend(ItemSerializer(items, many=True).data)

        except:
            reply['data'] = []
        return Response(reply, status.HTTP_200_OK)

如何将它们组合在一起，以便获得分页结果？
提前谢谢！在

Answer 1

首先，你现在做的事情太复杂了，没有理由。在

为了实现“paginatable”查询集，最好在简单的过滤器组合中更改owned_items()和{}，而不是模型方法。举例说明：

products = BaseItem.objects.filter(owner=request.user, owned=True)

而不是

^{pr2}$

这样，您就可以生成一个更容易分页的查询集：

user_items = BaseItem.objects.filter(
                 Q(owner=request.user, owned=True) |
                 Q(owner=request.user, dev=True)
             )

注意1:如果你愿意，你可以进一步简化事情，但这超出了你的问题范围。作为思考的食粮，看看这个：

user_items =  BaseItem.objects.filter(owner=request.user).distinct()

注意2:您应该为单个模型使用一个序列化程序，因为您所做的增加了复杂性而没有好处（高风险低回报的情况）

---

基于上述假设：

这里有一些方法可以实现您的目标：

1. 通过使用GeneriAPIView和ListModelMixin，您可以重构类，使{}方法具有自动分页功能：

   from rest_framework import mixins, generics
   
   class ItemsAPIView(mixins.ListModelMixin, generics.GenericAPIView,):
       permission_classes = (permissions.IsAuthenticated,)
       pagination_class = api_settings.DEFAULT_PAGINATION_CLASS
       serializer_class = OwnedItemSerializer
   
       # You can define .get in here if you really need it.
       # You can also override .list to add specific functionality
   

2. 如果您不想使用上述方法，并且希望保留您的APIView，那么您可以保留您的get方法并为其提供分页，如Q&A example所述：

   class ItemsAPIView(APIView):
       permission_classes = (permissions.IsAuthenticated,)
       pagination_class = api_settings.DEFAULT_PAGINATION_CLASS
       serializer_class = MyNewUnifiedSerializerClass
   
       def get(self, request):
           user_items =  BaseItem.objects.filter(
                             owner=request.user
                         ).distinct()
           page = self.paginate_queryset(user_items)
   
           if page is not None:
               serializer = self.serializer_class(page, many=True)
               return self.get_paginated_response(serializer.data)
   
           serializer = self.get_serializer(user_items, many=True)
           return Response(serializer.data)
   
       # Now add the pagination handlers taken from 
       #  django-rest-framework/rest_framework/generics.py
   
       @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)