Question

我想在我的API中显示分页功能，我正在使用APIView多个序列化程序。
我知道用ListView显示分页很容易我已经看到将ListModelMixin和APIView结合起来的地方，但如果我的代码如下：

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)

如何将它们组合起来以便获得分页结果？
提前谢谢！

Answer 1

首先，你目前正在做的事情太复杂而没有理由。

为了实现“可分页”查询集，最好在简单的过滤器组合中更改owned_items()和dev_items()，而不是模型方法。通过例子澄清：

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

而不是

products = BaseItem.objects.owned_items().filter(owner=request.user)

这样，您可以生成一个更易于分页的查询集：

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

注1：如果您愿意，可以进一步简化，但这超出了您的问题范围。作为思考的食物，请查看：

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

注2：您应该为单个模型使用单个序列化程序，因为您正在做的事情会增加复杂性而没有任何好处（高风险 - 低奖励情况）

通过上述提及并假定：

有一些方法可以实现您想要的目标：

利用GeneriAPIView和ListModelMixin，您可以通过自动分页.list()方法重构您的课程：

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

如果您不想使用上述内容，并希望保留APIView，那么您可以保留get方法并为其提供分页，如此处所述{ {3}}：

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)

将ListModelMixin与APIView组合以显示分页

1 个答案: