Django-RestFrameWork之分页 视图 路由 渲染器

时间：2022-11-11 08:55:05

目录

一、分页

二、视图

三、路由

四、渲染器

一、分页

试问如果当数据量特别大的时候，你是怎么解决分页的？

  • 方式a、记录当前访问页数的数据id
  • 方式b、最多显示120页等
  • 方式c、只显示上一页，下一页，不让选择页码，对页码进行加密

1、基于limit offset 做分页

from rest_framework.pagination import LimitOffsetPagination
 urlpatterns = [

     url(r'^admin/', admin.site.urls),

     url(r'^app01/(?P<version>[v1|v2]+)/', include('app01.urls'))

 ]

urls.py

 urlpatterns = [

     url(r'^index1/', views.IndexView1.as_view()),

     url(r'^index2/', views.IndexView2.as_view()),

     url(r'^index3/', views.IndexView3.as_view()),

     url(r'^index4/', views.IndexView4.as_view()),

     url(r'^index5/', views.IndexView5.as_view()),

 ]

app01.url

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from app01.serializes.myserializes import MySerializes

 from rest_framework.pagination import LimitOffsetPagination

 from app01 import models

 # =========== 可以自己进行自定制分页，基于limitoffset===================

 class P1(LimitOffsetPagination):

     max_limit = 3  # 最大限制默认是None

     default_limit =2  # 设置每一页显示多少条

     limit_query_param = 'limit'  # 往后取几条

     offset_query_param = 'offset'  # 当前所在的位置

 class IndexView2(APIView):

     #使用http://127.0.0.1:8080/app01/v1/index2/?offset=2&limit=4可进行判断

     def get(self,request,*args,**kwargs):

         user_list = models.UserInfo.objects.all()

         p1 = P1()#注册分页

         page_user_list = p1.paginate_queryset(queryset=user_list,request=request,view=self)

         print('打印的是分页的数据',page_user_list)

         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个

         # return Response(ser.data) #不含上一页下一页

         return p1.get_paginated_response(ser.data)

 =======================也可以用下面这种形式===========

 class BaseResponse(object):

     def __init__(self,code=1000,data=None,error=None):

         self.code = code

         self.data = data

         self.error = error

 class IndexView(views.APIView):

     '''第二种类表示的方式'''

     def get(self,request,*args,**kwargs):

         ret = BaseResponse()

         try:

             user_list = models.UserInfo.objects.all()

             p1 = P1()

             page_user_list = p1.paginate_queryset(queryset=user_list,request=request,view=self)

             ser = IndexSerializer(instance=page_user_list,many=True)

             ret.data = ser.data

             ret.next = p1.get_next_link()

         except Exception as e:

             ret.code= 1001

             ret.error = 'xxxx错误'

         return Response(ret.__dict__)

views.py

2、基于页码的分页

from rest_framework.pagination import PageNumberPagination
 # ======================基于页码实现的分页==============

 class P2(PageNumberPagination):

     #默认每页显示的数据条数

     page_size = 2

     #获取url参数中设置的每页显示数据条数

     page_size_query_param = 'size'

     #获取url中传入的页码key

     page_query_param = 'page'

     #最大支持的每页显示的数据条数

     max_page_size = 5

 class IndexView3(APIView):

     #使用http://127.0.0.1:8080/app01/v1/index3/?page=1&page_size=1可进行判断

     def get(self,request,*args,**kwargs):

         user_list = models.UserInfo.objects.all()

         #实例化分页对象，获取数据库中的分页数据

         p2 = P2()

         print(p2.page_size_query_description)

         page_user_list = p2.paginate_queryset(queryset=user_list,request=request,view=self)

         print('打印的是分页的数据',page_user_list)

         #序列化对象

         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个

         #生成分页和数据

         # return Response(ser.data) #不含上一页下一页

         return p2.get_paginated_response(ser.data)

views.py

3、基于Cursor的分页

2可能存在性能问题，如果用户吧page给改的很大，查询速度就会很慢。还有一种页码加密的方式，

 # =====================基于Cursor的分页============

 class P3(CursorPagination):

     # URL传入的游标参数

     cursor_query_param = 'cursor'

     # 默认每页显示的数据条数

     page_size = 2

     # URL传入的每页显示条数的参数

     page_size_query_param = 'size'

     # 每页显示数据最大条数

     max_page_size = 3

     # 根据ID从大到小排列

     ordering = "id"

 class IndexView4(APIView):

     #使用http://127.0.0.1:8080/app01/v1/index4/?cursor=cj0xJnA9NA%3D%3D&size=3可进行判断

     def get(self,request,*args,**kwargs):

         user_list = models.UserInfo.objects.all().order_by('-id')

         p3 = P3()#注册分页

         page_user_list = p3.paginate_queryset(queryset=user_list,request=request,view=self)

         print('打印的是分页的数据',page_user_list)

         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个

         # return Response(ser.data) #不含上一页下一页

         return p3.get_paginated_response(ser.data)

views.py

二、视图

写视图函数可继承的几个类，我们以前经常用到的是APIView，现在我们来了解一下其他的类，其中1、3、4用到的最多

需要导入的类

from rest_framework.views import APIView

from rest_framework.generics import GenericAPIView

from rest_framework.viewsets import GenericViewSet

from rest_framework.viewsets import ModelViewSet

1、APIView

 class IndexView2(APIView):

     def get(self,request,*args,**kwargs):

         user_list = models.UserInfo.objects.all()

         ser = MySerializes(instance=user_list,many=True)

         return Response(ser.data)

APIView

2、GenericAPIView(APIView)

 from rest_framework.response import Response

 from rest_framework.generics import GenericAPIView

 from app01 import models

 from app01.serializes.myserializes import MySerializes

 from rest_framework.pagination import LimitOffsetPagination

 class P1(LimitOffsetPagination):

     max_limit = 3  # 最大限制默认是None

     default_limit =2  # 设置每一页显示多少条

     limit_query_param = 'limit'  # 往后取几条

     offset_query_param = 'offset'  # 当前所在的位置

 class IndexView1(GenericAPIView):

     queryset = models.UserInfo.objects.all()

     serializer_class = MySerializes

     pagination_class = P1

     def get(self,request,*args,**kwargs):

         user_list = self.get_queryset()

         p1 = P1()  #注册分页

         data = p1.paginate_queryset(queryset=user_list,request=request,view=self)  #获取分页的数据

         ser = self.get_serializer(instance=data,many=True) #序列化

         return Response(ser.data)

GenericAPIView

3、 GenericViewSet(ViewSetMixin, generics.GenericAPIView)

增

    POST

    /users/

删

    DELETE

    /users/1/

改   #全部修改

    PUT

    /users/1/

    #局部修改

    patch

    /users/1/

查

    GET

    /users/

    GET

    /users/1/
在GET请求的时候如果带ID说明查一条，如果不带则查所有

原始的

 urlpatterns = [

     url(r'^index/$', views.IndexView.as_view()),

     url(r'^index/(?P<pk>\d+)$', views.IndexView.as_view()),

 ]

urls.py

 class IndexView(views.APIView):

     def get(self,request,*args,**kwargs):

         pk = kwargs.get('pk')

         if pk:

             pass # 获取单条信息

         else:

             pass # 获取列表信息

     def post(self,request,*args,**kwargs):

         pass

     def put(self,request,*args,**kwargs):

         pass

     def patch(self,request,*args,**kwargs):

         pass

     def delete(self,request,*args,**kwargs):

                 pass

views.py

用了GenericViewSet这种方式的时候注意url变了

 urlpatterns = [

     url(r'^index3/$', views.IndexView3.as_view({'get': 'list','post':'create'})),

     url(r'^index3/(?P<pk>\d+)/$', views.IndexView3.as_view({'get': 'retrieve'})),

 ]

urls.py

 class IndexView3(GenericViewSet):

     queryset = models.UserInfo.objects.all()

     serializer_class = MySerializes

     pagination_class = P1

     def list(self,request,*args,**kwargs):

         #获取列表信息

         return Response('...')

     def retrieve(self,request,*args,**kwargs):

         #获取单条数据

         return Response('xxx')

GenericViewSet

4、 ModelViewSet(mixins.CreateModelMixin,mixins.RetrieveModelMixin,mixins.UpdateModelMixin,mixins.DestroyModelMixin,mixins.ListModelMixin,GenericViewSet)

利用ModelViewSet增删改查不用自己写了，内部把增删改查都干了，当满足不了需求的时候我们也可以自定制

 urlpatterns = [

     url(r'^index4/', views.IndexView4.as_view({'get': 'list','post':'create'})),  #获取数据和添加数据

     url(r'^index4\.(?P<format>[a-z0-9]+)/', views.IndexView4.as_view({'get': 'list','post':'create'})), #.json想让页面上显示成json格式

     url(r'^index4/(?P<pk>\d+)/', views.IndexView4.as_view({'get': 'retrieve', 'delete': 'destroy','put':'partial_update'})), #查看单条，删除，修改数据

     url(r'^index4(?P<pk>\d+)\.(?P<format>[a-z0-9]+)/', views.IndexView4.as_view({'get': 'retrieve', 'delete': 'destroy','put':'partial_update'})),

 ]

urls.py

  注意啦：用ModelSerializer这种方法必须要用IndexSerializer(ModelSerializer)这种方式序列化

 class P2(PageNumberPagination):

     page_size = 3  #每一页显示的条数

     page_query_param = 'page' #获取参数中传入的页码

     page_size_query_param = 'size' #获取url参数中每页显示的数据条数

     max_page_size = 5

 class IndexSerializer(ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class IndexView4(ModelViewSet):

     queryset = models.UserInfo.objects.all()

     serializer_class = IndexSerializer

     pagination_class = P2

views.py

自定制

 class P2(PageNumberPagination):

     page_size = 3  #每一页显示的条数

     page_query_param = 'page' #获取参数中传入的页码

     page_size_query_param = 'size' #获取url参数中每页显示的数据条数

     max_page_size = 5

 class IndexSerializer(ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class IndexView4(ModelViewSet):

     queryset = models.UserInfo.objects.all()

     serializer_class = IndexSerializer

     pagination_class = P2

     def list(self, request, *args, **kwargs):

         '''获取get请求的所有'''

         pass

     def retrieve(self, request, *args, **kwargs):

         '''查看单条数据'''

         pass

     def destroy(self, request, *args, **kwargs):

         '''删除DELETE'''

         pass

     def create(self, request, *args, **kwargs):

         '''添加数据POST'''

         pass

     def update(self, request, *args, **kwargs):

         '''全部修改PUT'''

         pass

     def partial_update(self, request, *args, **kwargs):

         '''局部修改PATCH'''

         pass

基于ModelViewSet自定制

继承关系

Django-RestFrameWork之分页 视图 路由 渲染器

三、路由

第一类：自定义路由

# http://127.0.0.1:8000/api/v1/auth/

url(r'^auth/$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth.json # 想要让页面显示json格式

url(r'^auth\.(?P<format>[a-z0-9]+)$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth/1/

url(r'^auth/(?P<pk>\d+)/$', views.AuthView.as_view()),

# http://127.0.0.1:8000/api/v1/auth/1.json

url(r'^auth/(?P<pk>\d+)\.(?P<format>[a-z0-9]+)$', views.AuthView.as_view()),

class AuthView(views.APIView):

    def get(self,request,*args,**kwargs):

        return Response('...')

第二类：半自动路由

url(r'^index/$', views.IndexView.as_view({'get':'list','post':'create'})),

url(r'^index\.(?P<format>[a-z0-9]+)$', views.IndexView.as_view({'get':'list','post':'create'})),

url(r'^index/(?P<pk>\d+)/$', views.IndexView.as_view({'get':'retrieve','delete':'destroy','put':'update','patch':'partial_update'})),

url(r'^index(?P<pk>\d+)\.(?P<format>[a-z0-9]+)$', views.IndexView.as_view({'get':'retrieve','delete':'destroy','put':'update','patch':'partial_update'})),

class IndexView(viewsets.ModelViewSet):

    queryset = models.UserInfo.objects.all()

    serializer_class = IndexSerializer

    pagination_class = P2

第三类：全自动路由，会自动生成四个url

router = DefaultRouter()

router.register('index',views.IndexViewSet)

urlpatterns = [

    url(r'^', include(router.urls)),

]

class IndexViewSet(viewsets.ModelViewSet):

    queryset = models.UserInfo.objects.all()

    serializer_class = IndexSerializer

    pagination_class = P2

class IndexSerializer(serializers.ModelSerializer):

    class Meta:

        model = models.UserInfo

        fields = "__all__"

四、渲染器

根据 用户请求URL 或 用户可接受的类型，筛选出合适的 渲染组件。
用户请求URL：

  • http://127.0.0.1:8000/test/?format=json
  • http://127.0.0.1:8000/test.json

用户请求头：

  • Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8

1、. json

访问URL：

  • http://127.0.0.1:8000/test/?format=json
  • http://127.0.0.1:8000/test.json
  • http://127.0.0.1:8000/test/
 from django.conf.urls import url, include

 from web.views import s11_render

 urlpatterns = [

     url(r'^test/$', s11_render.TestView.as_view()),

     url(r'^test\.(?P<format>[a-z0-9]+)', s11_render.TestView.as_view()),

 ]

urls.py

 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from rest_framework import serializers

 from rest_framework.renderers import JSONRenderer

 from .. import models

 class TestSerializer(serializers.ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class TestView(APIView):

     renderer_classes = [JSONRenderer, ]

     def get(self, request, *args, **kwargs):

         user_list = models.UserInfo.objects.all()

         ser = TestSerializer(instance=user_list, many=True)

         return Response(ser.data)

views.py

2、.表格

访问URL：

  • http://127.0.0.1:8000/test/?format=admin
  • http://127.0.0.1:8000/test.admin
  • http://127.0.0.1:8000/test/
 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from rest_framework import serializers

 from rest_framework.renderers import AdminRenderer

 from .. import models

 class TestSerializer(serializers.ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class TestView(APIView):

     renderer_classes = [AdminRenderer, ]

     def get(self, request, *args, **kwargs):

         user_list = models.UserInfo.objects.all()

         ser = TestSerializer(instance=user_list, many=True)

         return Response(ser.data)

views.py

3、 Form表单

访问URL：

  • http://127.0.0.1:8000/test/?format=form
  • http://127.0.0.1:8000/test.form
  • http://127.0.0.1:8000/test/
 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from rest_framework import serializers

 from rest_framework.renderers import JSONRenderer

 from rest_framework.renderers import AdminRenderer

 from rest_framework.renderers import HTMLFormRenderer

 from .. import models

 class TestSerializer(serializers.ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class TestView(APIView):

     renderer_classes = [HTMLFormRenderer, ]

     def get(self, request, *args, **kwargs):

         user_list = models.UserInfo.objects.all().first()

         ser = TestSerializer(instance=user_list, many=False)

         return Response(ser.data)

views.py

4、 自定义显示模板

访问URL：

  • http://127.0.0.1:8000/test/?format=html
  • http://127.0.0.1:8000/test.html
  • http://127.0.0.1:8000/test/
 from django.conf.urls import url, include

 from web.views import s11_render

 urlpatterns = [

     url(r'^test/$', s11_render.TestView.as_view()),

     url(r'^test\.(?P<format>[a-z0-9]+)', s11_render.TestView.as_view()),

 ]

urls.py

 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from rest_framework import serializers

 from rest_framework.renderers import TemplateHTMLRenderer

 from .. import models

 class TestSerializer(serializers.ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class TestView(APIView):

     renderer_classes = [TemplateHTMLRenderer, ]

     def get(self, request, *args, **kwargs):

         user_list = models.UserInfo.objects.all().first()

         ser = TestSerializer(instance=user_list, many=False)

         return Response(ser.data, template_name='user_detail.html')

views.py

 <!DOCTYPE html>

 <html lang="en">

 <head>

     <meta charset="UTF-8">

     <title>Title</title>

 </head>

 <body>

     {{ user }}

     {{ pwd }}

     {{ ut }}

 </body>

 </html>

userdetail.html

5、浏览器格式API+JSON

访问URL：

  • http://127.0.0.1:8000/test/?format=api
  • http://127.0.0.1:8000/test.api
  • http://127.0.0.1:8000/test/
 #!/usr/bin/env python

 # -*- coding:utf-8 -*-

 from rest_framework.views import APIView

 from rest_framework.response import Response

 from rest_framework import serializers

 from rest_framework.renderers import JSONRenderer

 from rest_framework.renderers import BrowsableAPIRenderer

 from .. import models

 class TestSerializer(serializers.ModelSerializer):

     class Meta:

         model = models.UserInfo

         fields = "__all__"

 class CustomBrowsableAPIRenderer(BrowsableAPIRenderer):

     def get_default_renderer(self, view):

         return JSONRenderer()

 class TestView(APIView):

     renderer_classes = [CustomBrowsableAPIRenderer, ]

     def get(self, request, *args, **kwargs):

         user_list = models.UserInfo.objects.all().first()

         ser = TestSerializer(instance=user_list, many=False)

         return Response(ser.data, template_name='user_detail.html')

views.py

注意：如果同时多个存在时，自动根据URL后缀来选择渲染器。

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