05 Django REST Framework 分页

01-分页模式

rest framework中提供了三种分页模式：

from rest_framework.pagination import PageNumberPagination, LimitOffsetPagination, CursorPagination

02-全局配置

REST_FRAMEWORK = {
    'DEFAULT_PAGINATION_CLASS': 'rest_framework.pagination.LimitOffsetPagination',
    'PAGE_SIZE': 100
}

03-局部配置

我们可以在视图类中进行局部设置

class PublisherViewSet(ModelViewSet):
    queryset = models.Publisher.objects.all()
    serializer_class = PublisherModelSerializer
    pagination_class = PageNumberPagination  # 注意不是列表（只能有一个分页模式）

04-内置分页器-PageNumberPagination

按页码数分页，第n页，每页显示m条数据

例如：http://127.0.0.1:8000/api/article/?page=2&size=1

class MyPageNumber(PageNumberPagination):
    page_size = 2  # 每页显示多少条
    page_size_query_param = 'size'  # URL中每页显示条数的参数
    page_query_param = 'page'  # URL中页码的参数
    max_page_size = None  # 最大页码数限制

4.1 视图

class ArticleList(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all().order_by("id")
        # 分页
        page_obj = MyPageNumber()
        page_article = page_obj.paginate_queryset(queryset=article_list, request=request, view=self)
        ser_obj = ArticleSerializer(page_article, many=True)
        res["data"] = ser_obj.data
        return Response(res)

4.2 返回带页码链接的响应

class ArticleList(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all().order_by("id")
        # 分页
        page_obj = MyPageNumber()
        page_article = page_obj.paginate_queryset(queryset=article_list, request=request, view=self)
        ser_obj = ArticleSerializer(page_article, many=True)
        res["data"] = ser_obj.data
        return page_obj.get_paginated_response(res)

05-LimitOffsetPagination

分页，在n位置，向后查看m条数据

例如：http://127.0.0.1:8000/api/article/?offset=2&limit=2

5.1 分页器

# offset分页
class MyLimitOffset(LimitOffsetPagination):
    default_limit = 1
    limit_query_param = 'limit'
    offset_query_param = 'offset'
    max_limit = 999

5.2 视图

class ArticleList(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all().order_by("id")
        # 分页
        page_obj = MyLimitOffset()
        page_article = page_obj.paginate_queryset(queryset=article_list, request=request, view=self)
        ser_obj = ArticleSerializer(page_article, many=True)
        res["data"] = ser_obj.data
        return page_obj.get_paginated_response(res)

06-CursorPagination

加密分页，把上一页和下一页的id值记住

6.1 分页器

# 加密分页
class MyCursorPagination(CursorPagination):
    cursor_query_param = 'cursor'
    page_size = 1
    ordering = '-id'  # 重写要排序的字段

6.2 视图

class ArticleList(APIView):
    def get(self, request, *args, **kwargs):
        res = {"code": 0}
        article_list = models.Article.objects.all().order_by("id")
        # 分页
        page_obj = MyCursorPagination()
        page_article = page_obj.paginate_queryset(queryset=article_list, request=request, view=self)
        ser_obj = ArticleSerializer(page_article, many=True)
        res["data"] = ser_obj.data
        # return Response(res)
        return page_obj.get_paginated_response(res)