Django后端项目---- rest framework（3）

一、版本

程序也来越大时，可能通过版本不同做不同的处理

没用rest_framework之前，我们可以通过以下这样的方式去获取。

 1 class UserView(APIView):
 2     def get(self,request,*args,**kwargs):
 3         version = request.query_params.get('version')
 4         print(version)
 5         if version=='v1':
 6             #如果版本是v1
 7             ret = {
 8                 'code':111,
 9                 'msg':'版本一的内容'
10             }
11 
12         elif version=='v2':
13             # 如果是v2
14             ret = {
15                 'code': 112,
16                 'msg': '版本二的内容'
17             }
18         else:
19             ret = {
20                 'code': 0,
21                 'msg': '不支持其他版本'
22             }
23         return Response(ret)

View Code

现在我们来用rest_framework实现一下，有两种方式

1、基于url的方式

 #基于url传参的形式
     versioning_class = QueryParameterVersioning
    #http://127.0.0.1:8080/api/users/?version=v2
    
#基于url的形式
　　versioning_class = URLPathVersioning
　　#http://127.0.0.1:8080/api/v1/users/

具体步骤

1 REST_FRAMEWORK = {
2     'DEFAULT_VERSION': 'v1',  #默认的版本
3     'ALLOWED_VERSIONS': ['v1','v2'],  #允许的版本
4     'VERSION_PARAM': 'version',
5 }

1、配置

1 from django.conf.urls import url,include
2 from django.contrib import admin
3 
4 
5 urlpatterns = [
6     url(r'^admin/', admin.site.urls),
7     url(r'^api/(?P<version>[v1|v2]+)/', include('api.urls'), name='users-list'),
8 ]

urls.py

1 from api import views
2 urlpatterns = [
3     # url(r'^users/', views.UserView.as_view()),
4     url(r'^users/', views.UserView1.as_view()),
5 
6 ]

urls.py

 1 class UserView1(APIView):
 2     #基于url传参的形式
 3     # versioning_class = QueryParameterVersioning
 4     #http://127.0.0.1:8080/api/users/?version=v2
 5 
 6     #基于url的形式
 7     #http://127.0.0.1:8080/api/v1/users/
 8     versioning_class = URLPathVersioning
 9     def get(self,request,*args,**kwargs):
10         # self.dispatch
11         print(request.version)  #打印的是版本
12         print(request.versioning_scheme)  #打印的是对象
13         if request.version=='v2':
14             return Response('我是版本二')
15         elif request.version=='v1':
16             return Response('我是版本一')
17         else:
18             return Response('去去去')

views.py

注：在配置的时候

REST_FRAMEWORK = {
                'VERSION_PARAM':'version',
                'DEFAULT_VERSION':'v1',
                'ALLOWED_VERSIONS':['v1','v2'],
                # 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning" 
 　　　　　　　　　　#如果加上这个配置就不用versioning_class = QueryParameterVersioning这样在指定了，

　　　　　　　　　　 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning" }

附加：restful提供的反向生成

#http://127.0.0.1:8080/api/v1/users/

 1 #urls.py 
 2 #分发路由
 3 urlpatterns = [
 4     url(r'^admin/', admin.site.urls),
 5     url(r'^api/(?P<version>[v1|v2]+)/', include('api.urls')),
 6 ]
 7 
 8 #api.urls.py
 9 urlpatterns = [
10     url(r'^users/', views.UserView1.as_view(), name='users-list'),
11 ]
12 
13 #views.py 
14 导入类
15 from rest_framework.reverse import reverse
16 url = request.versioning_scheme.reverse(viewname='users-list',request=request)
17         print(url)

restfoamework反向解析

我们自己用django实现的，当前版本不一样的时候可以用这种方式

 from django.urls import reverse
        url = reverse(viewname='users-list',kwargs={'version':'v2'}) #指定的是v2就是v2，当你路径中输入v1的时候还是v2的路径
        print(url) #/api/v2/users/

2、基于子域名传参

 1 #分发url
 2             urlpatterns = [
 3                 #url(r'^admin/', admin.site.urls),
 4                 url(r'^api/', include('api.urls')),
 5             ]
 6 
 7             urlpatterns = [
 8                 url(r'^users/', views.UsersView.as_view(),name='u'),
 9             ]
10             
11             
12             class UsersView(APIView):
13                 
14                 def get(self,request,*args,**kwargs):
15                     self.dispatch
16                     print(request.version) # QueryParameterVersioning().detemiin_version()
17                     print(request.versioning_scheme) # QueryParameterVersioning()
18 
19             
20             REST_FRAMEWORK = {
21                 'VERSION_PARAM':'version',
22                 'DEFAULT_VERSION':'v1',
23                 'ALLOWED_VERSIONS':['v1','v2'],
24                 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"
25             }
26             
27             # C:WindowsSystem32driversetc
28             # vim /etc/hosts
29             127.0.0.1    v1.luffy.com
30             127.0.0.1    v2.luffy.com
31             
32             #配置ALLOWED_HOSTS = ['*']

基于子域名传参

如果遇到这样的错误

这是由于没有允许，解决办法，在settings里面配置一下

ALLOWED_HOSTS = ['*']

二、解析器：reqest.data取值的时候才执行

对请求的数据进行解析：是针对请求体进行解析的。表示服务器可以解析的数据格式的种类

django中的发送请求

#如果是这样的格式发送的数据，在POST里面有值
Content-Type: application/url-encoding.....
    request.body
    request.POST
    
#如果是发送的json的格式，在POST里面是没有值的，在body里面有值，可通过decode,然后loads取值        
Content-Type: application/json.....
    request.body
    request.POST

为了这种情况下每次都要decode，loads，显得麻烦，所以才有的解析器。弥补了django的缺点

 1 客户端：
 2             Content-Type: application/json
 3             '{"name":"alex","age":123}'
 4         
 5         服务端接收：
 6             读取客户端发送的Content-Type的值 application/json
 7             
 8             parser_classes = [JSONParser,FormParser]  #表示服务器可以解析的数据格式的种类
 9             media_type_list = ['application/json','application/x-www-form-urlencoded']
10         
11             如果客户端的Content-Type的值和 application/json 匹配：JSONParser处理数据
12             如果客户端的Content-Type的值和 application/x-www-form-urlencoded 匹配：FormParser处理数据
13         
14         
15         配置：
16             单视图：
17             class UsersView(APIView):
18                 parser_classes = [JSONParser,]
19                 
20             全局配置：
21                 REST_FRAMEWORK = {
22                     'VERSION_PARAM':'version',
23                     'DEFAULT_VERSION':'v1',
24                     'ALLOWED_VERSIONS':['v1','v2'],
25                     # 'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.HostNameVersioning"
26                     'DEFAULT_VERSIONING_CLASS':"rest_framework.versioning.URLPathVersioning",
27                     'DEFAULT_PARSER_CLASSES':[
28                         'rest_framework.parsers.JSONParser',
29                         'rest_framework.parsers.FormParser',
30                     ]
31                 }
32                 
33                 class UserView(APIView):
34                     def get(self,request,*args,**kwargs):
35                         return Response('ok')
36                     def post(self,request,*args,**kwargs):
37                         print(request.data)  #以后取值就在这里面去取值
38                         return Response('...')

具体讲解

传上传文件

1 from django.conf.urls import url, include
2 from web.views import TestView
3 
4 urlpatterns = [
5     url(r'test/(?P<filename>[^/]+)', TestView.as_view(), name='test'),
6 ]

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.request import Request
 6 from rest_framework.parsers import FileUploadParser
 7 
 8 
 9 class TestView(APIView):
10     parser_classes = [FileUploadParser, ]
11 
12     def post(self, request, filename, *args, **kwargs):
13         print(filename)
14         print(request.content_type)
15 
16         # 获取请求的值，并使用对应的JSONParser进行处理
17         print(request.data)
18         # application/x-www-form-urlencoded 或 multipart/form-data时，request.POST中才有值
19         print(request.POST)
20         print(request.FILES)
21         return Response('POST请求，响应内容')
22 
23     def put(self, request, *args, **kwargs):
24         return Response('PUT请求，响应内容')

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 <form action="http://127.0.0.1:8000/test/f1.numbers" method="post" enctype="multipart/form-data">
 9     <input type="text" name="user" />
10     <input type="file" name="img">
11 
12     <input type="submit" value="提交">
13 
14 </form>
15 </body>
16 </html>

upload.html

全局使用

1 REST_FRAMEWORK = {
2     'DEFAULT_PARSER_CLASSES':[
3         'rest_framework.parsers.JSONParser'
4         'rest_framework.parsers.FormParser'
5         'rest_framework.parsers.MultiPartParser'
6     ]
7 
8 }

settings.py

三、序列化

序列化用于对用户请求数据进行验证和数据进行序列化（为了解决queryset序列化问题）。

那什么是序列化呢？序列化就是把对象转换成字符串，反序列化就是把字符串转换成对象

models.py

from django.db import models

# Create your models here.
class Group(models.Model):
    title = models.CharField(max_length=32)
    mu = models.ForeignKey(to='Menu',default=1)

class UserInfo(models.Model):
    name = models.CharField(max_length=32)
    pwd = models.CharField(max_length=32)
    group = models.ForeignKey(to="Group")

    roles = models.ManyToManyField(to="Role")
class Menu(models.Model):
    name = models.CharField(max_length=21)

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

1、基本操作

 1 from django.shortcuts import render,HttpResponse
 2 from rest_framework.views import APIView
 3 from rest_framework.response import Response
 4 from rest_framework.versioning import BaseVersioning
 5 from rest_framework.versioning import QueryParameterVersioning  #获取version的值
 6 from rest_framework.versioning import URLPathVersioning #支持版本
 7 from rest_framework.versioning import HostNameVersioning
 8 from rest_framework.parsers import JSONParser  #解析器
 9 from rest_framework import serializers
10 from app03 import models
11 class UsersSerializer(serializers.Serializer):
12     name = serializers.CharField()  #字段名字
13     pwd = serializers.CharField()
14 
15 class UserView(APIView):
16     def get(self,request,*args,**kwargs):
17         # 方式一实现
18         # user_list = models.UserInfo.objects.values('name','pwd','group__mu','group__title')
19         # print(type(user_list))
20         # return Response(user_list)
21 
22         # 方式二之多对象
23         # user_list = models.UserInfo.objects.all()  #直接这样查会报错，借助他提供的系列化
24         # ser = UsersSerializer(instance=user_list,many=True) #可允许多个
25         # # print(type(ser))  #<class 'rest_framework.serializers.ListSerializer'>
26         # print(ser.data)  #返回的是一个有序字典
27 
28         #方式三之单对象
29         user = models.UserInfo.objects.all().first()
30         ser = UsersSerializer(instance=user,many=False)
31 
32         return Response(ser.data)

views.py

2、跨表

 x1 = serializers.CharField(source='group.mu.name')

如果你想跨表拿你任何需要的数据，都可以用上面的这种操作，内部做判断，如果可用内部就加括号调用了

 1 from rest_framework.views import APIView
 2 from rest_framework.response import Response
 3 from rest_framework import serializers
 4 from app03 import models
 5 class UsersSerializer(serializers.Serializer):
 6     name = serializers.CharField()  #字段名字
 7     pwd = serializers.CharField()
 8     # group = serializers.CharField()  #会显示对象
 9     # group_id = serializers.CharField()  #会显示id
10     x1 = serializers.CharField(source='group.mu.name')
11     roles = serializers.CharField(source='roles.all') #多对多关系的这样查出的是queryset对象
12 
13 class UserView2(APIView):
14     '''跨表操作'''
15     def get(self,request,*args,**kwargs):
16 
17         user = models.UserInfo.objects.all()
18         ser = UsersSerializer(instance=user,many=True)
19 
20         return Response(ser.data)

Views.py

3、复杂序列化

解决方案一：

 1 class MyCharField(serializers.CharField):
 2 
 3     def to_representation(self, value): ##打印的是所有的数据
 4         data_list = []
 5         for row in value:
 6             data_list.append(row.name)
 7         return data_list
 8 
 9 class UsersSerializer(serializers.Serializer):
10     name = serializers.CharField() # obj.name
11     pwd = serializers.CharField()  # obj.pwd
12     group_id = serializers.CharField() # obj.group_id
13     xxxx = serializers.CharField(source="group.title") # obj.group.title
14     x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
15     # x2 = serializers.CharField(source="roles.all") #  多对多关系的这样查出的是queryset对象
16     x2 = MyCharField(source="roles.all") # obj.mu.name

Views.py

解决方案二：

 1 class MyCharField(serializers.CharField):
 2     def to_representation(self, value):
 3         return {'id':value.pk, 'name':value.name}
 4 
 5 class UsersSerializer(serializers.Serializer):
 6     name = serializers.CharField() # obj.name
 7     pwd = serializers.CharField()  # obj.pwd
 8     group_id = serializers.CharField() # obj.group_id
 9     xxxx = serializers.CharField(source="group.title") # obj.group.title
10     x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
11     # x2 = serializers.CharField(source="roles.all") # obj.mu.name
12     x2 = serializers.ListField(child=MyCharField(),source="roles.all") # obj.mu.name

Views.py

解决方案三（推荐使用）

 1 class UsersSerializer(serializers.Serializer):
 2     name = serializers.CharField() # obj.name
 3     pwd = serializers.CharField()  # obj.pwd
 4     group_id = serializers.CharField() # obj.group_id
 5     xxxx = serializers.CharField(source="group.title") # obj.group.title
 6     x1 = serializers.CharField(source="group.mu.name") # obj.mu.name
 7     # x2 = serializers.CharField(source="roles.all") # obj.mu.name
 8     # x2 = serializers.ListField(child=MyCharField(),source="roles.all") # obj.mu.name
 9     x2 = serializers.SerializerMethodField()
10 
11     def get_x2(self,obj):  #get_字段名
12         print(obj)   ##UserInfo object
13         obj.roles.all()
14         role_list = obj.roles.filter(id__gt=1)
15         data_list = []
16         for row in role_list:
17             data_list.append({'pk':row.pk,'name':row.name})
18         return data_list
19

Views.py

4、基于Model

 1 class UsersSerializer(serializers.ModelSerializer):
 2 x1 = serializers.CharField(source='name')
 3 group = serializers.HyperlinkedIdentityField(view_name='detail')
 4 class Meta:
 5     
 6     model = models.UserInfo
 7     # fields = "__all__"
 8     fields = ['name','pwd','group','x1']  #自定义字段的时候注意要指定source,scource里面的数据必须是数据库有的数据
 9     depth = 1 #表示深度
10 
11 
12 class UsersView(APIView):
13     def get(self,request,*args,**kwargs):
14         self.dispatch
15         # 方式一：
16         # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
17         # return Response(user_list)
18 
19         # 方式二之多对象
20         user_list = models.UserInfo.objects.all()
21         # [obj1,obj2,obj3]
22         ser = UsersSerializer(instance=user_list,many=True)
23         return Response(ser.data)

Views.py

5、生成URL

 1 class UsersSerializer(serializers.ModelSerializer):  #
 2     group = serializers.HyperlinkedIdentityField(view_name='detail')
 3     class Meta:
 4         model = models.UserInfo
 5         fields = "__all__"
 6         fields = ['name', 'pwd','group']
 7         depth = 1
 8 
 9 
10 class UsersView(APIView):
11     def get(self,request,*args,**kwargs):
12         self.dispatch
13         # 方式一：
14         # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
15         # return Response(user_list)
16 
17         # 方式二之多对象
18         user_list = models.UserInfo.objects.all()
19         # [obj1,obj2,obj3]
20         ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
21         return Response(ser.data)

views.py

from django.conf.urls import url,include
from django.contrib import admin
from app03 import views
urlpatterns = [

    url(r'^users4/', views.UserView4.as_view(), name='xxx'), #吧users4的group的值反向生成users5的url
    url(r'^users5/(?P<pk>.*)', views.UserView5.as_view(), name='detail'),  #必须叫pk
    # url(r'^users4/(?P<pk>.*)', views.UserView4.as_view(), name='detail'),
]

6、全局生成URL

 1 class UsersSerializer(serializers.HyperlinkedModelSerializer): #继承他自动生成
 2     class Meta:
 3         model = models.UserInfo
 4         fields = "__all__"
 5 
 6         # fields = ['id','name','pwd']  
 7 
 8 class UsersView(APIView):
 9     def get(self,request,*args,**kwargs):
10         self.dispatch
11         # 方式一：
12         # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
13         # return Response(user_list)
14 
15         # 方式二之多对象
16         user_list = models.UserInfo.objects.all()
17         # [obj1,obj2,obj3]
18         ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
19         return Response(ser.data)

views.py

四、请求数据验证：

a、自己手写

 1 class PasswordValidator(object):
 2     def __init__(self, base):
 3         self.base = base
 4 
 5     def __call__(self, value):
 6         if value != self.base:
 7             message = '用户输入的值必须是 %s.' % self.base
 8             raise serializers.ValidationError(message)
 9 
10     def set_context(self, serializer_field):
11         """
12         This hook is called by the serializer instance,
13         prior to the validation call being made.
14         """
15         # 执行验证之前调用,serializer_fields是当前字段对象
16         pass
17 
18 class UsersSerializer(serializers.Serializer):
19         name = serializers.CharField(min_length=6)
20         pwd = serializers.CharField(error_messages={'required': '密码不能为空'}, validators=[PasswordValidator('666')])

views.py

b、基于model

 1 class PasswordValidator(object):
 2     def __init__(self, base):
 3         self.base = base
 4 
 5     def __call__(self, value):
 6         if value != self.base:
 7             message = '用户输入的值必须是 %s.' % self.base
 8             raise serializers.ValidationError(message)
 9 
10     def set_context(self, serializer_field):
11         """
12         This hook is called by the serializer instance,
13         prior to the validation call being made.
14         """
15         # 执行验证之前调用,serializer_fields是当前字段对象
16         pass
17 
18 class UsersSerializer(serializers.ModelSerializer):
19     class Meta:
20         model = models.UserInfo
21         fields = "__all__"
22         #自定义验证规则
23         extra_kwargs = {
24             'name': {'min_length': 6},
25             'pwd': {'validators': [PasswordValidator(666), ]}
26         }

views.py

使用

 1 class UsersView(APIView):
 2     def get(self,request,*args,**kwargs):
 3         self.dispatch
 4         # 方式一：
 5         # user_list = models.UserInfo.objects.all().values('name','pwd','group__id',"group__title")
 6         # return Response(user_list)
 7 
 8         # 方式二之多对象
 9         user_list = models.UserInfo.objects.all()
10         # [obj1,obj2,obj3]
11         ser = UsersSerializer(instance=user_list,many=True,context={'request':request})
12         return Response(ser.data)
13 
14     def post(self,request,*args,**kwargs):
15         ser = UsersSerializer(data=request.data)
16         if ser.is_valid():
17             print(ser.validated_data)
18         else:
19             print(ser.errors)
20         return Response('...')

viewS.py

钩子函数

def validate_字段(self,validated_value):
       raise ValidationError(detail='xxxxxx')
       return validated_value