django之drf框架（两个视图基类、5个扩展视图类、9个视图子类）
两个视图基类
APIView和GenericAPIView
drf提供的最顶层的父类就是APIView，以后所有的类都继承自他
GenericAPIView继承自APIView，他里面封装了一些工能
基于APIView+ModelSerializer+Resposne写5个接口
子路由：app01>>>urls.py
from django.urls import path, include
from . import views
urlpatterns = [
path('books/', views.BookView.as_view()),
path('books/' , views.BookDetailView.as_view()),
path('publish/', views.PublishView.as_view()),
path('publish/' , views.PublishDetailView.as_view()),
]
主路由：
from django.contrib import admin
from django.urls import path, include
urlpatterns = [
path('admin/', admin.site.urls),
path('api/v1/', include('app01.urls')),
]
序列化类：
class BookSerializer(serializers.ModelSerializer):
class Meta:
model = Book
fields = ['id', 'name', 'price', 'publish', 'authors', 'publish_detail', 'author_list']
extra_kwargs = {
'publish': {'write_only': True},
'authors': {'write_only': True},
'publish_detail': {'read_only': True},
'author_list': {'read_only': True}
}
模型表：
from django.db import models
class Book(models.Model):
name = models.CharField(max_length=32)
price = models.DecimalField(max_digits=5, decimal_places=2)
publish = models.ForeignKey(to='Publish', on_delete=models.CASCADE)
authors = models.ManyToManyField(to='Author')
@property
def publish_detail(self):
return {'name': self.publish.name, 'city': self.publish.city}
@property
def author_list(self):
l = []
for author in self.authors.all():
l.append({'name': author.name, 'age': author.age})
return l
def __str__(self):
return self.name
class Author(models.Model):
name = models.CharField(max_length=32)
age = models.IntegerField()
author_detail = models.OneToOneField(to='AuthorDetail', on_delete=models.CASCADE)
def __str__(self):
return self.name
class AuthorDetail(models.Model):
telephone = models.BigIntegerField()
birthday = models.DateField()
addr = models.CharField(max_length=64)
class Publish(models.Model):
name = models.CharField(max_length=32)
city = models.CharField(max_length=32)
email = models.EmailField()
def __str__(self):
return self.name
class Meta:
verbose_name = '出版社'
verbose_name_plural = verbose_name
视图类：
# 第一层：继承APIView+序列化类+Response写接口
class BookView(APIView):
def get(self, request):
book_list = Book.objects.all()
ser = BookSerializer(instance=book_list, many=True)
return Response(ser.data)
def post(self, request):
ser = BookSerializer(data=request.data)
if ser.is_valid():
ser.save()
return Response(ser.data)
else:
return Response(ser.errors)
class BookDetailView(APIView):
def put(self,request,*args,**kwargs):
book = Book.objects.filter(pk=kwargs.get('pk')).first()
ser = BookSerializer(instance=book,data=request.data)
if ser.is_valid():
ser.save()
return Response(ser.data)
else:
return Response(ser.errors)
def get(self,request,*args,**kwargs):
book = Book.objects.filter(pk=kwargs.get('pk')).first()
ser = BookSerializer(instance=book)
return Response(ser.data)
def delete(self,request,*args,**kwargs):
Book.objects.filter(pk=kwargs.get('pk')).delete()
return Response('')
继承GenericAPIView，编写五个接口
class BookView(GenericAPIView):
# 配置两个类属性
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
obj_list = self.get_queryset()
ser = self.get_serializer(instance=obj_list, many=True)
return Response(ser.data)
def post(self, request):
ser = self.get_serializer(data=request.data)
if ser.is_valid():
ser.save()
return Response(ser.data)
else:
return Response(ser.errors)
class BookDetailView(GenericAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
def put(self, request, *args, **kwargs):
# book = Book.objects.filter(pk=kwargs.get('pk')).first()
obj = self.get_object() # 获取单条数据
ser = self.get_serializer(instance=obj, data=request.data)
if ser.is_valid():
ser.save()
return Response(ser.data)
else:
return Response(ser.errors)
def get(self, request, *args, **kwargs):
obj = self.get_object()
ser = self.get_serializer(instance=obj)
return Response(ser.data)
def delete(self, request, *args, **kwargs):
self.get_object().delete()
return Response('')
继承GenericAPIView+序列化类+Response写接口
#1 继承GenericAPIView的写法
-1 在类中，写两个类属性：所有数据，序列化类
queryset = Book.objects.all()
serializer_class = BookSerializer
-2 获取所有要序列化的数据
self.get_queryset()
-3 获取序列化类
self.get_serializer(参数跟之前一样)
-4 获取单挑
self.get_object()
# 2 如果想快速写出Publish的5个接口，只需要修改视图类上的两个类属性即可，其他的不用动
queryset = Publish.objects.all()
serializer_class = PublishSerializer
# GenericAPIView源码分析
-1 继承了APIView
-2 有些类属性--》目前只记住两个queryset，serializer_class
queryset # 要序列化的所有数据
serializer_class # 序列化类
lookup_field = 'pk' # 查询单条，前端传入的参数对应值【pk】，转换器
filter_backends # 后续要学的，过滤
pagination_class # 后续要学的，分页
-3 有些对象方法
-get_queryset： 返回待序列化的数据
1 调用 .all
2 在子类中重写，控制要序列化的数据
-get_serializer： 返回 序列化类 以后用它
-本质就是---》 self.serializer_class(instance=object_list, many=True)
-内部调用了：self.get_serializer_class
-后期在子类中重写get_serializer_class，返回什么序列化类，以后就以哪个序列化类做序列化
- get_serializer_class 它是用来重写的
def get_serializer_class(self):
if self.request.method=='GET':
return '序列化的类'
else:
return '反序列化的类'
-get_object 获取单条---》根据它：lookup_field 获取
五个视图扩展类
继承GenericAPIView+5个视图扩展类+序列化类+Response
# 第三层：继承GenericAPIView+5个视图扩展类+序列化类+Response
from rest_framework.mixins import CreateModelMixin, ListModelMixin, RetrieveModelMixin, UpdateModelMixin,DestroyModelMixin
class BookView(GenericAPIView, CreateModelMixin, ListModelMixin):
# 配置两个类属性
queryset = Book.objects.all()
serializer_class = BookSerializer
def get(self, request):
return super().list(request)
def post(self, request):
return super().create(request)
class BookDetailView(GenericAPIView, RetrieveModelMixin, DestroyModelMixin, UpdateModelMixin):
queryset = Book.objects.all()
serializer_class = BookSerializer
def put(self, request, *args, **kwargs):
return super(BookDetailView, self).update(request, *args, **kwargs)
def get(self, request, *args, **kwargs):
return super().retrieve(request, *args, **kwargs)
def delete(self, request, *args, **kwargs):
return super().destroy(request, *args, **kwargs)
九个视图子类
这九个是视图子类，不需要额外继承GenericAPIView，只需要继承9个中其中某个，就会有某个或某几个接口，可以点击ListAPIView源码分析可知，该视图类有一个get方法，返回是一个list；该类继承的是GenericAPIView,父类有的方法，子类都可以使用，所以不再需要额外继承GenericAPIView
""" 基于上面再封装成九个视图类"""
from rest_framework.generics import ListAPIView, CreateAPIView, ListCreateAPIView
from rest_framework.generics import RetrieveAPIView, UpdateAPIView, DestroyAPIView, RetrieveDestroyAPIView, \
RetrieveUpdateAPIView, RetrieveUpdateDestroyAPIView # 没有DestroyUpdateAPIView方法，前提是没有查询删除不了
# 查询图书所有
class BookListView(ListAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 图书新增
class BookCreateView(CreateAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 图书修改
class BookUpdateView(UpdateAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 查询图书单条
class BookRetrieveView(RetrieveAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 删除图书
class BookDestroyView(DestroyAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 图书查询和删除功能
class BookRetrieveDestroyView(RetrieveDestroyAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 图书查询和修改功能
class BookRetrieveUpdateView(RetrieveUpdateAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 图书查询、修改和删除
# 查询图书单条
class BookRetrieveUpdateDestroyView(RetrieveUpdateDestroyAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
""" 总结：
ListAPIView + CreateAPIView = ListCreateAPIView 给BookView继承的
RetrieveAPIView + DestroyAPIView = RetrieveDestroyAPIView 给BookDetailView视图提供的
RetrieveAPIView + UpdateAPIView = RetrieveDestroyAPIView 给BookDetailView视图提供的
RetrieveAPIView + UpdateAPIView + DestroyAPIView = RetrieveUpdateDestroyAPIView 给BookDetailView视图提供的
发现Destroy 和Update 方法没有整合，
"""
最终通过继承可以写成下面两个类
""" 将上述的功能再整合一起"""
# 路由
urlpatterns = [
path('books/', views.BookView.as_view()),
path('books//' , views.BookView.as_view()),
]
# 视图
class BookAPIView(ListCreateAPIView):# 查询所有和新增一个
queryset = Book.objects.all()
serializer_class = BookSerializer
class BookDetailView(RetrieveUpdateDestroyAPIView): # 查询单条、更新和删除
queryset = Book.objects.all()
serializer_class = BookSerializer
基于ModelViewSet继承，编写5个类
要编写五个接口，对应写两个视图类，配置两条路由，通过观察发现连个视图类的代码几乎一模一样，我们借此引入了ModelViewSet类，继承自GenericAPIView，继承它只需要编写一个视图类
改变了路由写法—>
path('books/', views.BookAPIView.as_view({'get':'list','post':'create'})),
path('books/' , views.BookAPIView.as_view({'get':'retrieve','put':'update','delete':'destroy'})),
在路由里面指名两个get方法分别对应的类具体方法,当是get请求，访问这个地址，就执行视图类的list方法或retrieve方法
视图类：
from rest_framework.viewsets import ModelViewSet
class BookAPIView(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
点开ModelViewSet源码可知，ModelViewSet封装了ListAPIView、 CreateAPIView、RetrieveAPIView、UpdateAPIView、DestroyAPIView，直接继承ModelViewSet可以直接使用create、list、retrieve、destroy和update五种方法，但是我们查询单表和多条都是get的方法，所以需要在路由指名两个路由的get方法分别对应内置的方法（ path(‘books/’, views.BookAPIView.as_view({‘get’: ‘list’, ‘post’: ‘create’}))）
ViewSetMixin源码分析
只要是继承了ViewSetMixin，路由写法就变了
ViewSetMixin,不是视图类，支持路由映射的写法，核心原理是重写了as_view
请求来了：
原来：执行APIView的as_view内的view(request)
现在：执行ViewSetMixin的as_view内的view(request)
class ViewSetMixin:
@classonlymethod
def as_view(cls, actions=None, **initkwargs):
# actions={'get':'list','post':'create'}
def view(request, *args, **kwargs):
self = cls(**initkwargs) # self是BookView 视图类的对象
if 'get' in actions and 'head' not in actions:
actions['head'] = actions['get']
self.action_map = actions
for method, action in actions.items():
# 每次循环都是method:get,actions:list
# 去视图类对象中self反射list方法
# handler就是BookView的对象中的list方法
handler = getattr(self, action)
# 反射，设置值，把method:get，设置成list方法
# BookView类的对象，以后就是get方法也就是list方法
setattr(self, method, handler)
return self.dispatch(request, *args, **kwargs)
# 根据请求方式执行跟请求方式同名的方法，get请求-----》》》get方法
ViewSetMixin的总结
以后路由写法as_view()必须传入字典，写成映射关系
什么请求方式，就会去执行视图类中什么方法，根据映射关系去执行
以后只要继承了APIView，但是路由写法变化，就要继承ViewSetMixin
以后只要继承了GenericAPIView，但是路由写法变化，就要继承ViewSetMixin
视图类
# ViewSetMixin必须在APIView的前面
class UserView(ViewSetMixin, APIView):
def login(self, reqeust):
return Response('login')
路由
path('users/', views.UserView.as_view({'post':'login'})),
ReadOnlyModelViewSet（只读）
也是继承了GenericAPIView，但是内部封装的方法只有两个list、retrieve，只查询，查询单条和所有
路由写法也改变了
只能写两个方法，写多个会报错
path('books/', views.BookAPIView.as_view({'get':'list'})),
path('books/' , views.BookAPIView.as_view({'get':'retrieve'})),
drf之路由
视图类没有继承了ViewSetMixin，路由写法跟之前一样
path('books/', views.BookView.as_view())
只要视图类继承了ViewSetMixin，路由写法必须写成映射的方式
path('books/', views.BookView.as_view({'get': 'list'})),
只要视图类继承了ModelViewSet，还可以这么写
# 导入
from rest_framework.routers import SimpleRouter
# 实例化
router=SimpleRouter()
# 注册
router.register('books',views.BookAPIView,'books')
# 这句话就是相当于写了这两句
path('books/', views.BookAPIView.as_view({'get':'list','post':'create'})),
path('books/' , views.BookAPIView.as_view({'get':'retrieve','put':'update','delete':'destroy'})),
# 添加到路由中
urlpatterns += router.urls
假如视图类中有个login，如何应对
from rest_framework.decorators import action
class BookAPIView(ModelViewSet):
queryset = Book.objects.all()
serializer_class = BookSerializer
# 手动映射
# methods=None，请求方式
# detail=None，只能写True或False,如果写了False就是不带pk的路径，如果写了True就是带了pk的路径
# url_path=None，路径，会在之前的路径上，拼上这个路径，如果不写默认以函数名拼接
# url_path='login' 写了login就会在http://127.0.0.1:8000/api/v1/books/login/，books后面加上login
# url_name=None，别名，用作反向解析
@action(methods=['POST','GET'], detail=False) # 这个时候就只能POST，GET请求，别的请求不支持
def login(self, request):
return Response('login')
@action(methods=['POST'], detail=False) # 这个时候就只能POST请求，别的请求不支持
def register(self, request):
return Response('login')
总结
以后只要是继承了ViewSetMixin，就可以使用SimpleRouter方式写路由
#1 导入
from rest_framework.routers import SimpleRouter，DefaultRouter
#2 实例化 ：SimpleRouter，DefaultRouter
router = SimpleRouter()
或：认为他们一样即可---》DefaultRouter多一条路径
router = DefaultRouter()
#3 注册路径
router.register('books', views.BookView, 'books')
#4 加入到路由中:
# 方式一：（用这个）
urlpatterns += router.urls
# 方式二：
urlpatterns = [
path('', include(router.urls)),
]
# 5 list,create,retrieve,destroy,update--->自动映射--》SimpleRouter
# 6 视图类中自己的方法，再做映射--action装饰器
@action(methods=['POST'],detail=False,)
def login(self,request):
return Response('login')
认证组件
登录进系统后，再访问接口信息，需要携带登录信息，如果没携带就不允许访问，这个控制就是认证
之前我们学过cookie(浏览器自带的)和Session（后端存储的键值对）
写个登录
models.py
# 用户表用来做登录
class User(models.Model):
username = models.CharField(max_length=64)
password = models.CharField(max_length=64)
class UserToken(models.Model):
user = models.OneToOneField(to='User', on_delete=models.CASCADE)
token = models.CharField(max_length=64)
views.py
from .models import User, UserToken
from rest_framework.viewsets import ViewSet
import uuid
class UserView(ViewSet):
@action(methods=['POST'], detail=False)
def login(self, request):
username = request.data.get('username')
password = request.data.get('password')
user = User.objects.filter(username=username, password=password).first()
if user:
# 生成随机字符串，放到UserToken表中，把随机字符串返回给前端
token = str(uuid.uuid4())
# 如果之前UserToken中有数据，就要更新，没有就有新增
UserToken.objects.update_or_create(defaults={'token': token}, user_id=user.pk)
return Response({'code': 100, 'msg': 'ok', 'token': token})
else:
return Response({'code': 101, 'msg': 'no'})
app01>>>urls
# 导入
from rest_framework.routers import SimpleRouter
# 实例化
router=SimpleRouter()
# 注册
# router.register('books',views.BookAPIView,'books')
router.register('users',views.UserView,'users')
urlpatterns = []
# 添加到路由中
urlpatterns += router.urls
每当我提交一次POST请求，token就会刷新，UserToken表里的数据也会刷新
认证组件步骤
1.写一个认证类，继承BaseAuthentication
2.在类中重写 authenticate，在方法中完成认证，如果通过，返回两个值，如果失败，抛异常
def authenticate(self, request):
# 完成对用户的校验
# 当次请求request
token = request.query_params.get('token')
# 表中校验
user_token = UserToken.objects.filter(token=token).first()
# 当前登录用户
if user_token:
user = user_token.user
# 校验过后，返回两个值
return user, user_token
else:
raise AuthenticationFailed("token不合法")
3.是用认证类：需要放在登录后才能访问的视图类上
class BookView(ViewSet,ListCreateAPIView):
queryset = Book.objects.all()
serializer_class = BookSerializer
class BookDetailView(ViewSet,RetrieveUpdateDestroyAPIView):
authentication_classes = [LoginAuth]
queryset = Book.objects.all()
serializer_class = BookSerializer