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REST framework （组件使用之视图、序列化）

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

1 urlpatterns = [
2     url(r'^admin/', admin.site.urls),
3     url(r'^app01/(?P<version>[v1|v2]+)/', include('app01.urls'))
4 
5 ]

urls.py

1 urlpatterns = [
2     url(r'^index1/', views.IndexView1.as_view()),
3     url(r'^index2/', views.IndexView2.as_view()),
4     url(r'^index3/', views.IndexView3.as_view()),
5     url(r'^index4/', views.IndexView4.as_view()),
6     url(r'^index5/', views.IndexView5.as_view()),
7 
8 ]

app01.url

 1 from rest_framework.views import APIView
 2 from rest_framework.response import Response
 3 from app01.serializes.myserializes import MySerializes
 4 from rest_framework.pagination import LimitOffsetPagination
 5 from app01 import models
 6 
 7 # =========== 可以自己进行自定制分页，基于limitoffset===================
 8 class P1(LimitOffsetPagination):
 9     max_limit = 3  # 最大限制默认是None
10     default_limit =2  # 设置每一页显示多少条
11     limit_query_param = 'limit'  # 往后取几条
12     offset_query_param = 'offset'  # 当前所在的位置
13 
14 class IndexView2(APIView):
15     #使用http://127.0.0.1:8080/app01/v1/index2/?offset=2&limit=4可进行判断
16     def get(self,request,*args,**kwargs):
17         user_list = models.UserInfo.objects.all()
18         p1 = P1()#注册分页
19         page_user_list = p1.paginate_queryset(queryset=user_list,request=request,view=self)
20         print('打印的是分页的数据',page_user_list)
21         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个
22         # return Response(ser.data) #不含上一页下一页
23         return p1.get_paginated_response(ser.data)
24 
25 =======================也可以用下面这种形式===========
26 class BaseResponse(object):
27     def __init__(self,code=1000,data=None,error=None):
28         self.code = code
29         self.data = data
30         self.error = error
31 class IndexView(views.APIView):
32     '''第二种类表示的方式'''
33     def get(self,request,*args,**kwargs):
34         ret = BaseResponse()
35         try:
36             user_list = models.UserInfo.objects.all()
37             p1 = P1()
38             page_user_list = p1.paginate_queryset(queryset=user_list,request=request,view=self)
39             ser = IndexSerializer(instance=page_user_list,many=True)
40             ret.data = ser.data
41             ret.next = p1.get_next_link()
42         except Exception as e:
43             ret.code= 1001
44             ret.error = 'xxxx错误'
45         return Response(ret.__dict__)

views.py

2、基于页码的分页

from rest_framework.pagination import PageNumberPagination

 1 # ======================基于页码实现的分页==============
 2 class P2(PageNumberPagination):
 3     #默认每页显示的数据条数
 4     page_size = 2
 5     #获取url参数中设置的每页显示数据条数
 6     page_size_query_param = 'size'
 7     #获取url中传入的页码key
 8     page_query_param = 'page'
 9     #最大支持的每页显示的数据条数
10     max_page_size = 5
11 
12 class IndexView3(APIView):
13     #使用http://127.0.0.1:8080/app01/v1/index3/?page=1&page_size=1可进行判断
14     def get(self,request,*args,**kwargs):
15         user_list = models.UserInfo.objects.all()
16         #实例化分页对象，获取数据库中的分页数据
17         p2 = P2()
18         print(p2.page_size_query_description)
19         page_user_list = p2.paginate_queryset(queryset=user_list,request=request,view=self)
20         print('打印的是分页的数据',page_user_list)
21 
22         #序列化对象
23         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个
24 
25         #生成分页和数据
26         # return Response(ser.data) #不含上一页下一页
27         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，

 1 # =====================基于Cursor的分页============
 2 class P3(CursorPagination):
 3     # URL传入的游标参数
 4     cursor_query_param = 'cursor'
 5     # 默认每页显示的数据条数
 6     page_size = 2
 7     # URL传入的每页显示条数的参数
 8     page_size_query_param = 'size'
 9     # 每页显示数据最大条数
10     max_page_size = 3
11 
12     # 根据ID从大到小排列
13     ordering = "id"
14     
15 class IndexView4(APIView):
16     #使用http://127.0.0.1:8080/app01/v1/index4/?cursor=cj0xJnA9NA%3D%3D&size=3可进行判断
17     def get(self,request,*args,**kwargs):
18         user_list = models.UserInfo.objects.all().order_by('-id')
19         p3 = P3()#注册分页
20         page_user_list = p3.paginate_queryset(queryset=user_list,request=request,view=self)
21         print('打印的是分页的数据',page_user_list)
22         ser = MySerializes(instance=page_user_list,many=True)  #可允许多个
23         # return Response(ser.data) #不含上一页下一页
24         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

1 class IndexView2(APIView):
2     def get(self,request,*args,**kwargs):
3         user_list = models.UserInfo.objects.all()
4         ser = MySerializes(instance=user_list,many=True)
5         return Response(ser.data)

APIView

2、GenericAPIView(APIView)

 1 from rest_framework.response import Response
 2 from rest_framework.generics import GenericAPIView
 3 from app01 import models
 4 from app01.serializes.myserializes import MySerializes
 5 from rest_framework.pagination import LimitOffsetPagination
 6 class P1(LimitOffsetPagination):
 7     max_limit = 3  # 最大限制默认是None
 8     default_limit =2  # 设置每一页显示多少条
 9     limit_query_param = 'limit'  # 往后取几条
10     offset_query_param = 'offset'  # 当前所在的位置
11 
12 class IndexView1(GenericAPIView):
13     queryset = models.UserInfo.objects.all()
14     serializer_class = MySerializes
15     pagination_class = P1
16     def get(self,request,*args,**kwargs):
17         user_list = self.get_queryset()
18         p1 = P1()  #注册分页
19         data = p1.paginate_queryset(queryset=user_list,request=request,view=self)  #获取分页的数据
20         ser = self.get_serializer(instance=data,many=True) #序列化
21         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

1 urlpatterns = [
2 
3     url(r'^index/$', views.IndexView.as_view()),
4     url(r'^index/(?P<pk>d+)$', views.IndexView.as_view()),
5 ]

urls.py

 1 class IndexView(views.APIView):
 2 
 3     def get(self,request,*args,**kwargs):
 4         pk = kwargs.get('pk')
 5         if pk:
 6             pass # 获取单条信息
 7         else:
 8             pass # 获取列表信息
 9 
10     def post(self,request,*args,**kwargs):
11         pass
12 
13     def put(self,request,*args,**kwargs):
14         pass
15 
16     def patch(self,request,*args,**kwargs):
17         pass
18 
19     def delete(self,request,*args,**kwargs):
20                 pass

views.py

用了GenericViewSet这种方式的时候注意url变了

1 urlpatterns = [
2     url(r'^index3/$', views.IndexView3.as_view({'get': 'list','post':'create'})),
3     url(r'^index3/(?P<pk>d+)/$', views.IndexView3.as_view({'get': 'retrieve'})),
4    
5 ]

urls.py

 1 class IndexView3(GenericViewSet):
 2     queryset = models.UserInfo.objects.all()
 3     serializer_class = MySerializes
 4     pagination_class = P1
 5 
 6     def list(self,request,*args,**kwargs):
 7         #获取列表信息
 8         return Response('...')
 9 
10     def retrieve(self,request,*args,**kwargs):
11         #获取单条数据
12         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

1 urlpatterns = [
2 
3     url(r'^index4/', views.IndexView4.as_view({'get': 'list','post':'create'})),  #获取数据和添加数据
4     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
5     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
6     url(r'^index4(?P<pk>d+).(?P<format>[a-z0-9]+)/', views.IndexView4.as_view({'get': 'retrieve', 'delete': 'destroy','put':'partial_update'})),
7 
8 ]

urls.py

 1  注意啦：用ModelSerializer这种方法必须要用IndexSerializer(ModelSerializer)这种方式序列化
 2 class P2(PageNumberPagination):
 3     page_size = 3  #每一页显示的条数
 4     page_query_param = 'page' #获取参数中传入的页码
 5     page_size_query_param = 'size' #获取url参数中每页显示的数据条数
 6 
 7     max_page_size = 5
 8 
 9 class IndexSerializer(ModelSerializer):
10     class Meta:
11         model = models.UserInfo
12         fields = "__all__"
13 
14 class IndexView4(ModelViewSet):
15     queryset = models.UserInfo.objects.all()
16     serializer_class = IndexSerializer
17     pagination_class = P2

views.py

自定制

 1 class P2(PageNumberPagination):
 2     page_size = 3  #每一页显示的条数
 3     page_query_param = 'page' #获取参数中传入的页码
 4     page_size_query_param = 'size' #获取url参数中每页显示的数据条数
 5 
 6     max_page_size = 5
 7 
 8 class IndexSerializer(ModelSerializer):
 9     class Meta:
10         model = models.UserInfo
11         fields = "__all__"
12 
13 class IndexView4(ModelViewSet):
14     queryset = models.UserInfo.objects.all()
15     serializer_class = IndexSerializer
16     pagination_class = P2
17 
18     def list(self, request, *args, **kwargs):
19         '''获取get请求的所有'''
20         pass
21 
22     def retrieve(self, request, *args, **kwargs):
23         '''查看单条数据'''
24         pass
25     def destroy(self, request, *args, **kwargs):
26         '''删除DELETE'''
27         pass
28     def create(self, request, *args, **kwargs):
29         '''添加数据POST'''
30         pass
31     def update(self, request, *args, **kwargs):
32         '''全部修改PUT'''
33         pass
34     def partial_update(self, request, *args, **kwargs):
35         '''局部修改PATCH'''
36         pass

基于ModelViewSet自定制

继承关系

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/

1 from django.conf.urls import url, include
2 from web.views import s11_render
3 
4 urlpatterns = [
5     url(r'^test/$', s11_render.TestView.as_view()),
6     url(r'^test.(?P<format>[a-z0-9]+)', s11_render.TestView.as_view()),
7 ]

urls.py

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from rest_framework.views import APIView
 4 from rest_framework.response import Response
 5 from rest_framework import serializers
 6 
 7 from rest_framework.renderers import JSONRenderer
 8 
 9 from .. import models
10 
11 
12 class TestSerializer(serializers.ModelSerializer):
13     class Meta:
14         model = models.UserInfo
15         fields = "__all__"
16 
17 
18 class TestView(APIView):
19     renderer_classes = [JSONRenderer, ]
20 
21     def get(self, request, *args, **kwargs):
22         user_list = models.UserInfo.objects.all()
23         ser = TestSerializer(instance=user_list, many=True)
24         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/

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from rest_framework.views import APIView
 4 from rest_framework.response import Response
 5 from rest_framework import serializers
 6 
 7 from rest_framework.renderers import AdminRenderer
 8 
 9 from .. import models
10 
11 
12 class TestSerializer(serializers.ModelSerializer):
13     class Meta:
14         model = models.UserInfo
15         fields = "__all__"
16 
17 
18 class TestView(APIView):
19     renderer_classes = [AdminRenderer, ]
20 
21     def get(self, request, *args, **kwargs):
22         user_list = models.UserInfo.objects.all()
23         ser = TestSerializer(instance=user_list, many=True)
24         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/

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from rest_framework.views import APIView
 4 from rest_framework.response import Response
 5 from rest_framework import serializers
 6 
 7 from rest_framework.renderers import JSONRenderer
 8 from rest_framework.renderers import AdminRenderer
 9 from rest_framework.renderers import HTMLFormRenderer
10 
11 from .. import models
12 
13 
14 class TestSerializer(serializers.ModelSerializer):
15     class Meta:
16         model = models.UserInfo
17         fields = "__all__"
18 
19 
20 class TestView(APIView):
21     renderer_classes = [HTMLFormRenderer, ]
22 
23     def get(self, request, *args, **kwargs):
24         user_list = models.UserInfo.objects.all().first()
25         ser = TestSerializer(instance=user_list, many=False)
26         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/

1 from django.conf.urls import url, include
2 from web.views import s11_render
3 
4 urlpatterns = [
5     url(r'^test/$', s11_render.TestView.as_view()),
6     url(r'^test.(?P<format>[a-z0-9]+)', s11_render.TestView.as_view()),
7 ]

urls.py

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from rest_framework.views import APIView
 4 from rest_framework.response import Response
 5 from rest_framework import serializers
 6 from rest_framework.renderers import TemplateHTMLRenderer
 7 
 8 from .. import models
 9 
10 
11 class TestSerializer(serializers.ModelSerializer):
12     class Meta:
13         model = models.UserInfo
14         fields = "__all__"
15 
16 
17 class TestView(APIView):
18     renderer_classes = [TemplateHTMLRenderer, ]
19 
20     def get(self, request, *args, **kwargs):
21         user_list = models.UserInfo.objects.all().first()
22         ser = TestSerializer(instance=user_list, many=False)
23         return Response(ser.data, template_name='user_detail.html')

views.py

 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title>Title</title>
 6 </head>
 7 <body>
 8     {{ user }}
 9     {{ pwd }}
10     {{ ut }}
11 </body>
12 </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/

 1 #!/usr/bin/env python
 2 # -*- coding:utf-8 -*-
 3 from rest_framework.views import APIView
 4 from rest_framework.response import Response
 5 from rest_framework import serializers
 6 
 7 from rest_framework.renderers import JSONRenderer
 8 from rest_framework.renderers import BrowsableAPIRenderer
 9 
10 from .. import models
11 
12 
13 class TestSerializer(serializers.ModelSerializer):
14     class Meta:
15         model = models.UserInfo
16         fields = "__all__"
17 
18 
19 class CustomBrowsableAPIRenderer(BrowsableAPIRenderer):
20     def get_default_renderer(self, view):
21         return JSONRenderer()
22 
23 
24 class TestView(APIView):
25     renderer_classes = [CustomBrowsableAPIRenderer, ]
26 
27     def get(self, request, *args, **kwargs):
28         user_list = models.UserInfo.objects.all().first()
29         ser = TestSerializer(instance=user_list, many=False)
30         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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原文地址：https://www.cnblogs.com/zhangliang91/p/10926939.html