restful中的分页

普通分页

普通分页类似于Django中的分页

源码

class PageNumberPagination(BasePagination):
    """
    A simple page number based style that supports page numbers as
    query parameters. For example:

    http://api.example.org/accounts/?page=4
    http://api.example.org/accounts/?page=4&page_size=100
    """
    # The default page size.
    # Defaults to `None`, meaning pagination is disabled.
    page_size = api_settings.PAGE_SIZE

    # DjangoPaginator就是Django中的Paginator类
    django_paginator_class = DjangoPaginator

    # Client can control the page using this query parameter.
    page_query_param = 'page'
    page_query_description = _('A page number within the paginated result set.')

    # Client can control the page size using this query parameter.
    # Default is 'None'. Set to eg 'page_size' to enable usage.
    page_size_query_param = None
    page_size_query_description = _('Number of results to return per page.')

    # Set to an integer to limit the maximum page size the client may request.
    # Only relevant if 'page_size_query_param' has also been set.
    max_page_size = None

    last_page_strings = ('last',)

    template = 'rest_framework/pagination/numbers.html'

    invalid_page_message = _('Invalid page.')

源码重要的四个参数详解

# page_size是APISettings中的默认配置，用户配置则使用用户配置，未配置则使用DEFAULTS配置，默认为None
page_size = api_settings.PAGE_SIZE
# ？之后的参数，如127.0.0.1/books/?page=3
page_query_param = 'page'
# 每页最多显示的条数，如：127.0.0.1/books/?page=3&size=5
page_size_query_param = 'size'
# 超出后每页的最多显示数
max_page_size = None

简单使用

REST_FRAMEWORK = {
    # 每页的显示数量
    'PAGE_SIZE': 2
}

views.py文件

from rest_framework.pagination import PageNumberPagination


class Book(ViewSetMixin, APIView):
    def get_all(self, request):
        response = {'status': 100, 'msg': '查询成功'}
        book_list = models.Book.objects.all()
        # 实例化产生一个分页对象
        page = PageNumberPagination()
        # 第一个参数:要分页的数据,第二个参数request对象,第三个参数,当前视图对象
        page_list = page.paginate_queryset(book_list, request, self)
        # 再序列化的时候,用分页之后的数据
        ser = mySer.BookSerializer(instance=page_list, many=True)
        response['data'] = ser.data
        return Response(response)

或者可以自定义类来修改数据属性

from rest_framework.pagination import PageNumberPagination

class MyPageNumberPagination(PageNumberPagination):
    page_size = 3
    page_query_param = 'test'
    page_size_query_param = 'size'
    max_page_size = 5


class Book(ViewSetMixin, APIView):
    def get_all(self, request):
        response = {'status': 100, 'msg': '查询成功'}
        book_list = models.Book.objects.all()
        # 实例化产生一个分页对象
        page = MyPageNumberPagination()
        # 第一个参数:要分页的数据,第二个参数request对象,第三个参数,当前视图对象
        page_list = page.paginate_queryset(book_list, request, self)
        # 再序列化的时候,用分页之后的数据
        ser = mySer.BookSerializer(instance=page_list, many=True)
        response['data'] = ser.data
        return Response(response)

不继承修改属性

from rest_framework.pagination import PageNumberPagination


class Book(ViewSetMixin, APIView):
    def get_all(self, request):
        response = {'status': 100, 'msg': '查询成功'}
        book_list = models.Book.objects.all()
        # 实例化产生一个分页对象
        # 不继承来修改对象的值
        page = PageNumberPagination()
        page.page_size = 2
        page.page_query_param = 'bb'
        # page = MyPageNumberPagination()
        # 第一个参数:要分页的数据,第二个参数request对象,第三个参数,当前视图对象
        page_list = page.paginate_queryset(book_list, request, self)
        # 再序列化的时候,用分页之后的数据
        ser = mySer.BookSerializer(instance=page_list, many=True)
        response['data'] = ser.data
        return Response(response)
        # 会带着链接,和总共的条数(不建议用)
        # return page.get_paginated_response(ser.data)
        # return Response(ser.data)

偏移分页

源码

class LimitOffsetPagination(BasePagination):
    """
    A limit/offset based style. For example:

    http://api.example.org/accounts/?limit=100
    http://api.example.org/accounts/?offset=400&limit=100
    """
    default_limit = api_settings.PAGE_SIZE
    limit_query_param = 'limit'
    limit_query_description = _('Number of results to return per page.')
    offset_query_param = 'offset'
    offset_query_description = _('The initial index from which to return the results.')
    max_limit = None
    template = 'rest_framework/pagination/numbers.html'

重要参数详解

# 默认显示数量
default_limit = api_settings.PAGE_SIZE
# 标杆值，从哪开始偏移
offset_query_param = 'offset'
# 根据标杆值的偏移量
limit_query_param = 'limit'
# 超出后限制最多的显示多少条
max_limit = None

其余用法跟普通分页相同，都是实例化对象，对象调用paginate_queryset(self, queryset, request, view=None)方法，参数解释（queryset：要分页的数据，request：request对象，view：当前视图对象）

加密分页

源码

class CursorPagination(BasePagination):
    """
    The cursor pagination implementation is necessarily complex.
    For an overview of the position/offset style we use, see this post:
    https://cra.mr/2011/03/08/building-cursors-for-the-disqus-api
    """
    cursor_query_param = 'cursor'
    cursor_query_description = _('The pagination cursor value.')
    page_size = api_settings.PAGE_SIZE
    invalid_cursor_message = _('Invalid cursor')
    ordering = '-created'
    template = 'rest_framework/pagination/previous_and_next.html'

    # Client can control the page size using this query parameter.
    # Default is 'None'. Set to eg 'page_size' to enable usage.
    page_size_query_param = None
    page_size_query_description = _('Number of results to return per page.')

    # Set to an integer to limit the maximum page size the client may request.
    # Only relevant if 'page_size_query_param' has also been set.
    max_page_size = None

    # The offset in the cursor is used in situations where we have a
    # nearly-unique index. (Eg millisecond precision creation timestamps)
    # We guard against malicious users attempting to cause expensive database
    # queries, by having a hard cap on the maximum possible size of the offset.
    offset_cutoff = 1000

重要参数解释

# 按哪个字段排序
ordering = 'id'
# ？后的参数
cursor_query_param = 'cursor'
# 每页的显示数量
page_size = api_settings.PAGE_SIZE
# 每页最多显示的条数
page_size_query_param = 'size'
# 最大显示数
max_page_size = None

最后返回时调用对象的get_paginated_response(self, data)方法，返回一个加密后的页数链接