Mixin扩展类

特点：

1）继承自object

2）Mixin不能单独使用，需要配合GenericAPIView使用

5个扩展类：
1）ListModelMixin：list

class ListModelMixin(object):
    def list(self, request, *args, **kwargs):
        """封装获取一组数据通用代码"""
        queryset = self.get_queryset()
        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

2）CreateModelMixin：create

class CreateModelMixin(object):
    def create(self, request, *args, **kwargs):
        """封装新增数据通用代码"""
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()  # 调用序列化器类中的create
        return Response(serializer.data, status=status.HTTP_201_CREATED)

3）RetrieveModelMixin：retrieve

class RetrieveModelMixin(object):
    def retrieve(self, request, *args, **kwargs):
        """封装获取指定数据的通用代码"""
        instance = self.get_object()
        serializer = self.get_serializer(instance)
        return Response(serializer.data)

4）UpdateModelMixin：update

class UpdateModelMixin(object):
    def update(self, request, *args, **kwargs):
        """封装更新指定数据的通用代码"""
        instance = self.get_object()
        serializer = self.get_serializer(instance, data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()  # 调用序列化器类中的update
        return Response(serializer.data)

5）DestroyModelMixin：destroy

class DestroyModelMixin(object):
    def destroy(self, request, *args, **kwargs):
        """封装删除指定数据的通用代码"""
        instance = self.get_object()
        instance.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

Mixin改写RestAPI接口

# views.py
from rest_framework.generics import GenericAPIView
from rest_framework import mixins
from rest_framework import status

from booktest.serializers import BookInfoSerializer
from booktest.models import BookInfo

# /books/
class BookListView(mixins.ListModelMixin,
                   mixins.CreateModelMixin,
                   GenericAPIView):
    """
    获取所有图书、增加图书
    """
    # 指定视图所使用的序列化器类
    serializer_class = BookInfoSerializer
    # 指定视图所使用的查询集
    queryset = BookInfo.objects.all()

    def get(self, request):
        """
        获取所有的图书数据
        """
        return self.list(request)

    def post(self, request):
        """
        新增一个图书数据
        """
        return self.create(request)

# /books/(?P<pk>\d+)/
class BookDetailView(mixins.RetrieveModelMixin,
                     mixins.UpdateModelMixin,
                     mixins.DestroyModelMixin,
                     GenericAPIView):
    """
    获取、修改、删除指定图书
    """
    # 指定视图所使用的序列化器类
    serializer_class = BookInfoSerializer
    # 指定视图所使用的查询集
    queryset = BookInfo.objects.all()

    def get(self, request, pk):
        """
        获取指定图书
        """
        return self.retrieve(request, pk)

    def put(self, request, pk):
        """
        修改指定图书
        """
        return self.update(request, pk)

    def delete(self, request, pk):
        """
        删除指定图书：
        """
        return self.destroy(request, pk)