Django Rest Framework 3.1打破了pagination.PaginationSerializer

Question

我刚刚更新到Django Rest Framework 3.1,似乎一切都崩溃了.

在我的serializers.py我有以下代码:

class TaskSerializer(serializers.ModelSerializer):
    class Meta:
    model = task
    exclude = ('key', ...)

class PaginatedTaskSerializer(pagination.PaginationSerializer):
    class Meta:
        object_serializer_class = TaskSerializer

哪个工作得很好.现在随着3.1的发布,我无法找到关于如何做同样事情的例子,因为PaginationSerializer已经不存在了.我试图子类PageNumberPagination并使用它的默认paginate_queryset和get_paginated_response方法,但我不能再将它们的结果序列化.

换句话说,我的问题是我不能再这样做了:

class Meta:
    object_serializer_class = TaskSerializer

有任何想法吗？

提前致谢

Answer 1

我想我想出来了(至少大部分):

从一开始我们应该使用的是:

只需使用内置的分页器并将其更改views.py为:

from rest_framework.pagination import PageNumberPagination

class CourseListView(AuthView):
    def get(self, request, format=None):
        """
        Returns a JSON response with a listing of course objects
        """
        courses = Course.objects.order_by('name').all()
        paginator = PageNumberPagination()
        # From the docs:
        # The paginate_queryset method is passed the initial queryset 
        # and should return an iterable object that contains only the 
        # data in the requested page.
        result_page = paginator.paginate_queryset(courses, request)
        # Now we just have to serialize the data just like you suggested.
        serializer = CourseSerializer(result_page, many=True)
        # From the docs:
        # The get_paginated_response method is passed the serialized page 
        # data and should return a Response instance.
        return paginator.get_paginated_response(serializer.data)

对于所需的页面大小刚好设置PAGE_SIZE在settings.py:

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.PageNumberPagination',
    'PAGE_SIZE': 15
}

您现在应该已经全部设置了响应正文中存在的所有选项(计数,下一个和后一个链接),就像更新之前一样.

然而还有一件事情让我感到困扰:我们也应该能够获得新的html分页控件,这些控件由于某些原因暂时缺失...

我绝对可以在这个问题上使用更多的建议......

Answer 2

我不确定这是否是完全正确的方法,但它适合我的需要.它使用Django Paginator和自定义序列化器.

这是我的View类,它检索序列化的对象

class CourseListView(AuthView):
    def get(self, request, format=None):
        """
        Returns a JSON response with a listing of course objects
        """
        courses = Course.objects.order_by('name').all()
        serializer = PaginatedCourseSerializer(courses, request, 25)
        return Response(serializer.data)

这是使用我的课程序列化程序的黑客一起串行化程序.

from django.core.paginator import Paginator, PageNotAnInteger, EmptyPage

class PaginatedCourseSerializer():
    def __init__(self, courses, request, num):
        paginator = Paginator(courses, num)
        page = request.QUERY_PARAMS.get('page')
        try:
            courses = paginator.page(page)
        except PageNotAnInteger:
            courses = paginator.page(1)
        except EmptyPage:
            courses = paginator.page(paginator.num_pages)
        count = paginator.count

        previous = None if not courses.has_previous() else courses.previous_page_number()
        next = None if not courses.has_next() else courses.next_page_number()
        serializer = CourseSerializer(courses, many=True)
        self.data = {'count':count,'previous':previous,
                 'next':next,'courses':serializer.data}

这给了我一个类似于旧分页器给出的行为的结果.

{
    "previous": 1,
    "next": 3,
    "courses": [...],
    "count": 384
}

我希望这有帮助.我仍然认为必须采用一种更好的方式来实现新的API,但它并没有很好地记录下来.如果我想出更多的东西,我会编辑我的帖子.

编辑

我想我已经找到了一种更好,更优雅的方法来创建我自己的自定义分页器来获得像以前用旧的Paginated Serializer类那样的行为.

这是一个自定义的分页器类.我重载了响应和下一页的方法来获得我想要的结果(即?page=2代替完整的url).

from rest_framework.response import Response
from rest_framework.utils.urls import replace_query_param

class CustomCoursePaginator(pagination.PageNumberPagination):
    def get_paginated_response(self, data):
        return Response({'count': self.page.paginator.count,
                         'next': self.get_next_link(),
                         'previous': self.get_previous_link(),
                         'courses': data})

    def get_next_link(self):
        if not self.page.has_next():
            return None
        page_number = self.page.next_page_number()
        return replace_query_param('', self.page_query_param, page_number)

    def get_previous_link(self):
        if not self.page.has_previous():
            return None
        page_number = self.page.previous_page_number()
        return replace_query_param('', self.page_query_param, page_number)

然后我的课程视图与您实现它的方式非常相似,只是这次使用Custom paginator.

class CourseListView(AuthView):
    def get(self, request, format=None):
        """
        Returns a JSON response with a listing of course objects
        """
        courses = Course.objects.order_by('name').all()
        paginator = CustomCoursePaginator()
        result_page = paginator.paginate_queryset(courses, request)
        serializer = CourseSerializer(result_page, many=True)
        return paginator.get_paginated_response(serializer.data)

现在我得到了我正在寻找的结果.

{
    "count": 384,
    "next": "?page=3",
    "previous": "?page=1",
    "courses": []
}

我仍然不确定它如何适用于Browsable API(我没有使用drf的这个功能).我想你也可以为此创建自己的自定义类.我希望这有帮助!