二、视图

2.1 普通方式

• views.py

  from rest_framework.views import APIView
  from rest_framework.response import Response
  
  class BookView(APIView):
      """ 全部 """
  
      def get(self, request):
          book_list = Book.objects.all()
          ret = BookSerializer(book_list, many=True)
          return Response(ret.data)
  
      def post(self, request):
          serializer = BookSerializer(data=request.data)
          if serializer.is_valid():
              serializer.save()
              return Response(serializer.data)
          else:
              return Response(serializer.errors)
  
            
  class BookEditView(RetrieveUpdateDestroyAPIView):
      """ 局部 """
  
      def get(self, request, id):
          book_obj = Book.objects.filter(id=id).first()
          ret = BookSerializer(book_obj)
          return Response(ret.data)
  
      def put(self, request, id):
          book_obj = Book.objects.filter(id=id).first()
          serializer = BookSerializer(book_obj, data=request.data, partial=True)  # partial=True，允许部分更新
          if serializer.is_valid():
              serializer.save()
              # return Response(serializer.validated_data)  # validated_data，验证成功的数据
              return Response(serializer.data)  # data 验证成功，并序列化好的数据
          else:
              return Response(serializer.errors)
  
      def delete(self, request, id):
          book_obj = Book.objects.filter(id=id).first()
          book_obj.delete()
          return Response("")
  
  

2.2 代码优化

• urls.py

  urlpatterns = [
      path('list', BookView.as_view()),
      path('retrieve/<int:id>', BookEditView.as_view()),
  ]
  
  

• views.py

  from rest_framework.views import APIView
  from rest_framework.response import Response
  
  class GenericAPIView(APIView):
      """ 通用类 """
      query_set = None
      serializer_class = None
  
      def get_queryset(self):
          """ 获取model对象 """
          return self.query_set
  
      def get_serializer(self, *args, **kwargs):
          """
          获取serializer对象
          :param args: 实例化所需的参数
          :param kwargs:
          :return: 序列化器对象
          """
          return self.serializer_class(*args, **kwargs)
  
  
  class ListModelMixin(object):
      """ 混合类：全部GET """
  
      def list(self, request):
          queryset = self.get_queryset()
          ret = self.get_serializer(queryset, many=True)
          return Response(ret.data)
  
  
  class CreateModelMixin(object):
      """ 混合类：全部POST """
  
      def create(self, request):
          serializer = self.get_serializer(data=request.data)
          if serializer.is_valid():
              serializer.save()
              return Response(serializer.data)
          else:
              return Response(serializer.errors)
  
  
  class RetrieveModelMixin(object):
      """ 混合类：局部GET """
  
      def retrieve(self, request, id):
          book_obj = self.get_queryset().filter(id=id).first()
          ret = self.get_serializer(book_obj)
          return Response(ret.data)
  
  
  class UpdateModelMixin(object):
      """ 混合类：局部PUT """
  
      def update(self, request, id):
          book_obj = self.get_queryset().filter(id=id).first()
          serializer = self.get_serializer(book_obj, data=request.data, partial=True)
          if serializer.is_valid():
              serializer.save()
              return Response(serializer.data)
          else:
              return Response(serializer.errors)
  
  
  class DestroyModelMixin(object):
      """ 混合类：局部DELETE """
  
      def destroy(self, request, id):
          book_obj = self.get_queryset().filter(id=id).first()
          book_obj.delete()
          return Response("")
  
  
  class ListCreateAPIView(GenericAPIView, ListModelMixin, CreateModelMixin):
      """ 基础继承类 """
      pass
  
  
  class RetrieveUpdateDestroyAPIView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
      """ 基础继承类 """
      pass
  
  
  class BookView(ListCreateAPIView):
      query_set = Book.objects.all()
      serializer_class = BookSerializer
  
      def get(self, request):
          return self.list(request)
  
      def post(self, request):
          return self.create(request)
  
  
  class BookEditView(RetrieveUpdateDestroyAPIView):
      """ 部分更新 """
      query_set = Book.objects.all()
      serializer_class = BookSerializer
  
      def get(self, request, id):
          return self.retrieve(request, id)
  
      def put(self, request, id):
          return self.update(request, id)
  
      def delete(self, request, id):
          return self.destroy(request, id)
  
  

2.3 最终版（利用框架）

• 框架原生提供了大部分所需的基础类

  from rest_framework import views
  from rest_framework import generics
  from rest_framework import mixins
  from rest_framework import viewsets
  

• urls.py

  urlpatterns = [
      path('list', BookModelViewSet.as_view({"get": "list", "post": "create"})),
      # 使用框架提供的方法时，id改成pk
      path('retrieve/<int:pk>', BookModelViewSet.as_view({"get": "retrieve", "put": "update", "delete": "destroy"})),
  ]
  
  

• views.py

  class ViewSetMixin(object):
      def as_view(self):
          """
          重写aa_views()方法，以实现按照路由中的参数去匹配
          get-->list、put-->update ...
          """
          pass
  
  
  # rest_framework已经提供了ViewSetMixin
  from rest_framework.viewsets import ViewSetMixin
  
  
  class ModelViewSet(ViewSetMixin, GenericAPIView, ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
      """ 基础继承类 """
      pass
  
  
  # rest_framework也已经提供了ModelViewSet
  from rest_framework.viewsets import ModelViewSet
  
  
  class BookModelViewSet(ModelViewSet):
      """ 最终合并到一个类 """
      # query_set = Book.objects.all()
      queryset = Book.objects.all()  # 使用框架的ModelViewSet，改成queryset
      serializer_class = BookSerializer