Django Rest Framework（八）之分页

urls.py

from django.conf.urls import url,include
from django.contrib import admin
from api import views

urlpatterns = [
　　url(r'^(?P<version>[v1|v2]+)/page/$',views.PagerViews.as_view()),
]

 

models.py

from django.db import models

# Create your models here.


class UserGroup(models.Model):
    title = models.CharField(max_length=32)


class UserInfo(models.Model):
    user_type_choices = (
        (1,'普通用户'),
        (2,'VIP'),
        (3,'SVIP'),
    )
    user_type = models.IntegerField(choices=user_type_choices)

    username = models.CharField(max_length=32,unique=True)
    password = models.CharField(max_length=64)

    group = models.ForeignKey("UserGroup")
    roles = models.ManyToManyField("Role")


class UserToken(models.Model):
    user = models.OneToOneField(to='UserInfo')
    token = models.CharField(max_length=64)


class Role(models.Model):
    title = models.CharField(max_length=32)

 

使用django自带的分页类

views.py

from django.shortcuts import render,HttpResponse

from rest_framework.views import APIViewfrom api import models
from rest_framework.response import Response  　　　　　　　　#渲染
from rest_framework.pagination import PageNumberPagination  #系统自带的默认的分页方法


#序列化分页类
class PageSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

class PagerViews(APIView):
    def get(self,request,*args,**kwargs):

        #①默认获取所有数据，不分页
        # obj= models.Role.objects.all()
        # ser = PageSerializer(instance=obj,many=True)

        # return Response(ser.data)


        #②分页，获取所有数据
        obj= models.Role.objects.all()

        #创建分页对象
        pg = PageNumberPagination()
        pager_roles = pg.paginate_queryset(queryset=obj,request=request,view=self)    #queryset表示从数据库拿数据，view为当前视图，为self

        ser = PageSerializer(instance=pager_roles, many=True)
        #print (pager_roles)　　　　　　　　　　　　　　　　　　#打印分页的结果对像
        return Response(ser.data)    　　　　　　　　　　　　　#返回渲染的数据
        #return pg.get_paginated_response(ser.data)　　　　　　　　　　#这里返回的数据中包含前一页和后一页的链接地址，

 

根据PageNumberPagination源码得知，设置分页的时候还需要定义page_size(即一页显示多少条数据)，源码如下

class PageNumberPagination(BasePagination):
   
    page_size = api_settings.PAGE_SIZE　　　　　　　　#这里设置page_size

    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.')

    
    page_size_query_param = None
    page_size_query_description = _('Number of results to return per page.')

   
    max_page_size = None

    last_page_strings = ('last',)

    template = 'rest_framework/pagination/numbers.html'

    invalid_page_message = _('Invalid page.')

 

所以设置settings.py

REST_FRAMEWORK = {
    "DEFAULT_VERSIONING_CLASS":"rest_framework.versioning.URLPathVersioning",
    "DEFAULT_VERSION":"v1",
    "ALLOWED_VERSIONS":['v1','v2'],
    "VERSION_PARAM":'version',
    "DEFAULT_PARSER_CLASSES":['rest_framework.parsers.JSONParser','rest_framework.parsers.FormParser'],
    "PAGE_SIZE": 3
}

 

访问测试：http://127.0.0.1:8000/api/v1/page/?page=2

 

自定义分页类

from rest_framework.response import Response  #渲染
from rest_framework.pagination import PageNumberPagination  #f分页


#自定义分页类（字段均取自源码）
class MyPageNumberPagination(PageNumberPagination):

    page_size = 4                       #一页显示几条数据（源码里用的这个字段，不能变）
    page_size_query_param = 'size'
    max_page_size = 8                       #一页最大显示多少条数据
　　 page_query_param = 'page'　　　　　　　　 #源码默认为page，可自定义。但是访问的时候参数要写对


class PageSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

class PagerViews(APIView):
    def get(self,request,*args,**kwargs):
        #获取所有数据
        obj= models.Role.objects.all()

        #创建分页对象pg = MyPageNumberPagination()
        pager_roles = pg.paginate_queryset(queryset=obj,request=request,view=self)    #queryset表示从数据库拿数据，view为当前视图，为self

        ser = PageSerializer(instance=pager_roles, many=True)
        #print (pager_roles)
        return Response(ser.data)　　　　　　　　　　　　　　　　　　#这里同上
        #return pg.get_paginated_response(ser.data)　　　　　　　　#这里同上

 

访问测试http://127.0.0.1:8000/api/v1/page/?page=1&size=5 表示一页显示5条数据

 

 

LimitOffsetPagination

urls.py 不变

 

views.py

 

from rest_framework.response import Response  #渲染
from rest_framework.pagination import LimitOffsetPagination 　　　　　　#导入Limit类

class PageSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

class PagerViews(APIView):
    def get(self,request,*args,**kwargs):

        #获取所有数据
        obj= models.Role.objects.all()

        #创建分页对象
        pg = LimitOffsetPagination()　　　　　　　　#实例化Limit
      
        pager_roles = pg.paginate_queryset(queryset=obj,request=request,view=self)    #queryset表示从数据库拿数据，view为当前视图，为self

        ser = PageSerializer(instance=pager_roles, many=True)
        #print (pager_roles)
        #return Response(ser.data)
        return pg.get_paginated_response(ser.data)

 

 

访问地址：http://127.0.0.1:8000/api/v1/page/?offset=1&limit=5    其中，offset索引从0开始,limit表示每页显示多少条数据

 

同样，根据limitoffsetPagenation源码也可以自定义分页类

 

LimitOffsetPagination一部分源码

class LimitOffsetPagination(BasePagination):
    
    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'

 

根据源码自定义limit分页类

from rest_framework.response import Response  #渲染
from rest_framework.pagination import LimitOffsetPagination 　　　　　　#导入Limit类


#自定义Limit分页类
class MyLimitOffsetPagination(LimitOffsetPagination):
    # default_limit = api_settings.PAGE_SIZE　　　　　　　　　　　　#源码里用default_limit类指定限制每页多少条数据
    default_limit = 2
    limit_query_param = 'limit'
    offset_query_param = 'offset'
    max_limit = 5　　　　　　　　　　　　#最大显示几条数据


class PageSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

class PagerViews(APIView):
    def get(self,request,*args,**kwargs):

        #获取所有数据
        obj= models.Role.objects.all()

        #创建分页对象
        pg = myLimitOffsetPagination()　　　　　　　　#实例化Limit类
      
        pager_roles = pg.paginate_queryset(queryset=obj,request=request,view=self)    #queryset表示从数据库拿数据，view为当前视图，为self

        ser = PageSerializer(instance=pager_roles, many=True)
        #print (pager_roles)
        #return Response(ser.data)
        return pg.get_paginated_response(ser.data)

 

访问地址不变

 

 加密分页 CursorPagination

urls.py不变

 

查看CursorPagination源码

class CursorPagination(BasePagination):
    
    cursor_query_param = 'cursor'
    cursor_query_description = _('The pagination cursor value.')
    page_size = api_settings.PAGE_SIZE
    invalid_cursor_message = _('Invalid cursor')
    ordering = '-created'　　　　　　　　　　　　　　　　　　#根据那个字段排序，-表示倒序

    template = 'rest_framework/pagination/previous_and_next.html'

  
    page_size_query_param = None
    page_size_query_description = _('Number of results to return per page.')

   
    max_page_size = None

 

views.py（自定义加密分页类）

from rest_framework.response import Response  #渲染
from rest_framework.pagination import CursorPagination　　#引入加密分页类

#自定义加密分页类

class MyCursorPagination(CursorPagination):
    cursor_query_param = 'cursor'       #url参数
    #page_size = api_settings.PAGE_SIZE　　　　　　　　　　#默认情况下，加密分页类也是用的page_size字段来显示几条数据
    page_size = 2
    ordering = 'id'                   #根据什么字段进行排序
    page_size_query_param = "lll"　　　　　　#每页显示多少条数据的url参数
    max_page_size = 4

    template = 'rest_framework/pagination/previous_and_next.html'       #结果渲染到哪个页面，可以自定义


class PageSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Role
        fields = "__all__"

class PagerViews(APIView):
    def get(self,request,*args,**kwargs):


        #获取所有数据
        obj= models.Role.objects.all()

        #创建分页对象
        pg = MyCursorPagination()　　　　#实例化加密分页对象
       
        pager_roles = pg.paginate_queryset(queryset=obj,request=request,view=self)    #queryset表示从数据库拿数据，view为当前视图，为self

        ser = PageSerializer(instance=pager_roles, many=True)
        #print (pager_roles)
        #return Response(ser.data)
        return pg.get_paginated_response(ser.data)

 

初次访问时访问地址 http://127.0.0.1:8000/api/v1/page/?lll=4      #lll代表每页显示几条数据