四、drf视图组件

drf视图组件

一、基于APIView

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from app01 import models
  from app01.ser import BookSerializer
  from rest_framework.views import APIView
  from rest_framework.response import Response
  
  # 自定义一个Response对象
  class MyResponse():
      def __init__(self):
          self.status = '1000'
          self.msg = '成功'
      @property
      def get_dict(self):
          return self.__dict__
  
  class BookView1(APIView):
      # 查询一条数据
      def get(self,request,pk):
          response_msg = MyResponse()
          book_obj = models.Book.objects.filter(id=pk).first()
          book_ser = BookSerializer(instance=book_obj)
          response_msg.data = book_ser.data
          return Response(response_msg.get_dict)
  
      # 删除一条数据
      def delete(self,request,pk):
          response_msg = MyResponse()
          models.Book.objects.filter(pk=pk).delete()
          response_msg.msg = '删除成功'
          return Response(response_msg.get_dict)
  
      # 修改一条数据
      def put(self,request,pk):
          response_msg = MyResponse()
          book_obj = models.Book.objects.filter(pk=pk).first()
          book_ser = BookSerializer(instance=book_obj,data=request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '校验失败，请稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  class BooksView1(APIView):
      # 查询所有数据
      def get(self,request):
          response_msg = MyResponse()
          books_obj = models.Book.objects.all()
          books_ser = BookSerializer(instance=books_obj,many=True)
          response_msg.data = books_ser.data
          return Response(response_msg.get_dict)
  
      # 新增一条数据
      def post(self,request):
          response_msg = MyResponse()
          book_ser = BookSerializer(data=request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.msg = '新增成功'
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '新增失败，情稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  

• urls.py

  url(r'^book1/(?P<pk>d+)', views.BookView1.as_view()),
  url(r'^books1/', views.BooksView1.as_view()),
  

• 总结

  1. 继承关系: APIView继承View
  2. APIView基于View的拓展:
      APIView重写了View的dispatch方法, 在该方法中实现了实现了一下功能:
      (1) 对来的原生请求对象request进行了封装.
      (2) 提供了对包装过后的请求对象的三段认证: 认证, 权限控制, 频率控制
      (3) 重写了View中通过本次请求的方式动态的反射到自定义继承APIView类实例化的对象中定义的请求方法
      (4) 使用异常处理处理2,3步骤中的异常
      (5) 处理完毕异常以后使用drf的response对象对请求响应
  3. 针对路由配置
      路由中的有名分组必须指定pk, 视图中使用必须使用相同的关键字参数接受
  

二、基于GenericView

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  # 最好使用ModelSerializer类，不用重写update和create方法
  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from rest_framework.generics import GenericAPIView
  class BookGenericView2(GenericAPIView):
      # queryset要传queryset对象，查询了所有的图书
      # serializer_class使用哪个序列化类来序列化这堆数据
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # queryset=models.Book.objects.all()
      # 查询一条数据
      def get(self,request,pk):
          response_msg = MyResponse()
          book_obj = self.get_object()
          book_ser = self.get_serializer(book_obj)
          response_msg.data = book_ser.data
          return Response(response_msg.get_dict)
  
      # 删除一条数据
      def delete(self,request,pk):
          response_msg = MyResponse()
          self.get_object().delete()
          response_msg.msg = '删除成功'
          return Response(response_msg.get_dict)
  
      # 修改一条数据
      def put(self,request,pk):
          response_msg = MyResponse()
          book_obj = self.get_object()
          book_ser = self.get_serializer(book_obj,request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '校验失败，请稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  class BooksGenericView2(GenericAPIView):
      # queryset要传queryset对象，查询了所有的图书
      # serializer_class使用哪个序列化类来序列化这堆数据
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # queryset=models.Book.objects.all()
      # 查询所有数据
      def get(self,request):
          response_msg = MyResponse()
          books_obj = self.get_queryset()
          books_ser = self.get_serializer(books_obj,many=True)
          response_msg.data = books_ser.data
          return Response(response_msg.get_dict)
  
      # 新增一条数据
      def post(self,request):
          response_msg = MyResponse()
          book_ser = self.get_serializer(data=request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.msg = '新增成功'
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '新增失败，情稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  

• urls.py

  url(r'^bookG2/(?P<pk>d+)',views.BookGenericView2.as_view()),
  url(r'^bookGs2/',views.BooksGenericView2.as_view()),
  

• 总结

  1.GenericAPIView继承自APIView，它在APIView的功能上增加了两个功能：
  	- 通用的模型类(传入需要序列化的模型数据)	queryset = None; 
  	- 通用的序列化器(传入对应的序列化器对象)	serializer_class = None
    	- 通用的有名分组名
      	lookup_field = 'pk':好像不能改
          lookup_url_kwarg = None:可以改,改成自己的有名分组名即可
  2.三个常用方法
  	- get_queryset() # 获取queryset对象，用于查询多条数据
  	- get_object()	# 获取一条对象数据
  	- get_serializer(*args, **kwargs)	# 获取序列化器对象，该传什么参数就传什么参数
  4.在写视图类时,模型表必须是queryset对象(加上objects),即queryset = Book.objects
  5.
  

三、基于GenericView+5个视图拓展类

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  # 最好使用ModelSerializer类，不用重写update和create方法
  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from  rest_framework.mixins import ListModelMixin,CreateModelMixin,UpdateModelMixin,DestroyModelMixin,RetrieveModelMixin
  class BookGenericView3(GenericAPIView,UpdateModelMixin,DestroyModelMixin,RetrieveModelMixin):
      """
      UpdateModelMixin:修改
      DestroyModelMixin:删除
      RetrieveModelMixin:查询一条数据
      """
      # queryset要传queryset对象，查询了所有的图书
      # serializer_class使用哪个序列化类来序列化这堆数据
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # 查询一条数据
      def get(self,request,pk):
          return self.retrieve(request,pk)
  
      # 删除一条数据
      def delete(self,request,pk):
          return self.destroy(request,pk)
  
      # 修改一条数据
      def put(self,request,pk):
          return self.update(request,pk)
  class BooksGenericView3(GenericAPIView,ListModelMixin,CreateModelMixin):
      """
      ListModelMixin:查询所有
      CreateModelMixin:创建一条数据
      """
      # queryset要传queryset对象，查询了所有的图书
      # serializer_class使用哪个序列化类来序列化这堆数据
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # queryset=models.Book.objects.all()
      # 查询所有数据
      def get(self,request):
          return self.list(request)
  
      # 新增一条数据
      def post(self,request):
          return self.create(request)
  

• urls.py

  url(r'^bookG3/(?P<pk>d+)',views.BookGenericView3.as_view()),
  url(r'^bookGs3/',views.BooksGenericView3.as_view()),
  

• 总结

  1.使用GenericAPIView写不同类的接口，只是queryset参数和serializer_class参数的不同，其他的方法几乎完全一样
  2.这五个扩展类需要搭配GenericAPIView父类，因为五个扩展类的实现需要调用GenericAPIView提供的序列化器与数据库查询的方法。
  3.DestroyModelMixin、RetrieveModelMixin、UpdateModelMixin的路由中，必须使用pk
  
  # ListModelMixin 	     内部封装了list方法, 实现了查询所有数据
  	提供list(request, *args, **kwargs)方法快速实现列表视图，返回200状态码。
      该Mixin的list方法会对数据进行过滤和分页。
  # CreateModelMixin 		 内部封装了create方法, 实现了新增一条数据
  	提供create(request, *args, **kwargs)方法快速实现创建资源的视图，成功返回201状态码。
  	如果序列化器对前端发送的数据验证失败，返回400错误。
  # RetrieveModelMixin	 内部封装了retrieve方法, 实现了查询一条数据
  	提供retrieve(request, *args, **kwargs)方法，可以快速实现返回一个存在的数据对象。
  	如果存在，返回200， 否则返回404。
  # UpdateModelMixin       内部封装了update方法, 实现了更新一条数据
   	提供update(request, *args, **kwargs)方法，可以快速实现更新一个存在的数据对象。
      同时也提供partial_update(request, *args, **kwargs)方法，可以实现局部更新。
      成功返回200，序列化器校验数据失败时，返回400错误。
  # DestroyModelMixin      内部封装了destroy方法，实现了删除一条数据
  	提供destroy(request, *args, **kwargs)方法，可以快速实现删除一个存在的数据对象。
  	成功返回204，不存在返回404。
  4.在写视图类时,模型表必须是queryset对象(加上objects),即queryset = Book.objects
  

四、基于GenericView+九个拓展类

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  # 最好使用ModelSerializer类，不用重写update和create方法
  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from rest_framework.generics import GenericAPIView,
      CreateAPIView, DestroyAPIView, UpdateAPIView, ListAPIView, RetrieveAPIView, 
      ListCreateAPIView, RetrieveDestroyAPIView, RetrieveUpdateDestroyAPIView, RetrieveUpdateAPIView
  
  # 创建一个数据
  class BookCreateAPIView(CreateAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
  
  # 删除一个数据
  class BookDestroyAPIView(DestroyAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
      
  # 修改一个数据
  class BookUpdateAPIView(UpdateAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
      
  # 获取所有数据
  class BookListAPIView(ListAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
  # 获取一个数据
  class BookRetrieveAPIView(RetrieveAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
      
  # 获取所有数据和创造一个数据
  class BookListCreateAPIView(ListCreateAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
  
  # 获取一个数据和删除一个数据
  class BookRetrieveDestroyAPIView(RetrieveDestroyAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
  
  # 获取一个数据和修改一个数据
  class BookRetrieveUpdateAPIView(RetrieveUpdateAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
     
  # 获取一个数据和修改一个数据和删除一个数据
  class BookRetrieveUpdateDestroyAPIView(RetrieveUpdateDestroyAPIView):
      queryset = Book.objects
      serializer_class = BookModelSerializer
  

• urls.py

  url(r'^books/$', views.BookModelViewSet.as_view(),
  url(r'^books/(?P<pk>d+)',views.BookModelViewSet.as_view(),
  

• 总结

  1.不需要指定路由的actions参数,因为根本就没有
  2.在写视图类时,模型表必须是queryset对象(加上objects),即queryset = Book.objects
  

五、基于ModelViewSet

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  # 最好使用ModelSerializer类，不用重写update和create方法
  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from rest_framework.viewsets import ModelViewSet
  class BookGenericView4(ModelViewSet):
      """
      5个接口都有，但是路由有点问题
      问？怎么区别那种请求触发该请求方式的方法
      需要在路由中添加一个参数：actions={'get':'list','post':'create','get':'retrieve','delete':'destroy','put':'update'}
      """
      queryset = models.Book.objects
      serializer_class = BookSerializer
  

• urls.py

  url(r'^bookG4/(?P<pk>d+)', views.BookGenericView4.as_view(actions={'delete':'destroy','get':'retrieve','put':'update'})), # 这个路由中有删除一个、查询一个、修改一个的请求
      url(r'^bookGs4/', views.BookGenericView4.as_view(actions={'get':'list','post':'create'})), # 这个路由中有查询所有、增添一个的请求
  

• 总结

  1.路由处的as_view()中必须传一个action参数（字典），格式：action={'get':'list','post':'creat'}
  2.在写视图类时,模型表必须是queryset对象(加上objects),即queryset = Book.objects
  

六、继承ViewSetMixin

• models.py

  from django.db import models
  class Book(models.Model):
      id = models.AutoField(primary_key=True)
      title = models.CharField(max_length=32)
      price = models.DecimalField(max_digits=5,decimal_places=2)
      publish = models.CharField(max_length=32)
      author = models.CharField(max_length=32)
  

• ser.py（自定义序列化文件）

  # 最好使用ModelSerializer类，不用重写update和create方法
  from app01 import models
  from rest_framework import serializers
  class BookSerializer(serializers.ModelSerializer):
      class Meta:
          model = models.Book
          fields = "__all__"
  

• view.py

  from rest_framework.viewsets import ViewSetMixin
  class BookGenericView5(ViewSetMixin,GenericAPIView):
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # 查询一条数据
      def get_one_data(self,request,pk):
          response_msg = MyResponse()
          book_obj = self.get_object()
          book_ser = self.get_serializer(book_obj)
          response_msg.data = book_ser.data
          return Response(response_msg.get_dict)
  
      # 删除一条数据
      def delete_one_data(self,request,pk):
          response_msg = MyResponse()
          self.get_object().delete()
          response_msg.msg = '删除成功'
          return Response(response_msg.get_dict)
  
      # 修改一条数据
      def put_one_data(self,request,pk):
          response_msg = MyResponse()
          book_obj = self.get_object()
          book_ser = self.get_serializer(book_obj,request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '校验失败，请稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  class BooksGenericView5(ViewSetMixin,GenericAPIView):
      queryset = models.Book.objects
      serializer_class = BookSerializer
      # 查询所有数据
      def get_all_data(self,request):
          response_msg = MyResponse()
          books_obj = self.get_queryset()
          books_ser = self.get_serializer(books_obj,many=True)
          response_msg.data = books_ser.data
          return Response(response_msg.get_dict)
  
      # 新增一条数据
      def post_one_data(self,request):
          response_msg = MyResponse()
          book_ser = self.get_serializer(data=request.data)
          if book_ser.is_valid():
              book_ser.save()
              response_msg.msg = '新增成功'
              response_msg.data = book_ser.data
          else:
              response_msg.status = '1001'
              response_msg.msg = '新增失败，情稍后再试'
              response_msg.data = book_ser.errors
          return Response(response_msg.get_dict)
  

• urls.py

  url(r'^bookG5/(?P<pk>d+)', views.BookGenericView5.as_view(actions={'delete':'delete_one_data','get':'get_one_data','put':'put_one_data'})), # 这个路由中有删除一个、查询一个、修改一个的请求
      url(r'^bookGs5/', views.BooksGenericView5.as_view(actions={'get':'get_all_data','post':'post_one_data'})), # 这个路由中有查询所有、增添一个的请求
  

• 总结

  1.ViewSetMixin类一定要放在GenericAPIView类前面
  2.ViewSetMixin类可以与APIView类使用,请求函数和使用APIView类时一样,只不过可以自定义自己的请求方式名
  	def get_all_data(,self,request):
          pass
  3.自定义自己的请求方式函数时,需要在路由的as_view()中的action中设置好映射关系
  	url(r'^index/',view.Data.as_view(action={'get':'get_all_data'}))
  4.在写视图类时,模型表必须是queryset对象(加上objects),即queryset = Book.objects