GenericAPIView类与几个扩展类的综合使用

• 五个扩展类

扩展类	作用	封装的方法	状态码（成功，失败）
ListModelMixin	查询多条数据	list	200
CreateModelMixin	新增一条数据	create	201，400
RetrieveModelMixin	查询一条数据	retrieve	200，404
UpdateModelMixin	更新一条数据	update，partial_update	200，400
DestroyModelMixin	删除一条数据	destroy	204，404

这五个扩展类需要搭配GenericAPIView (或者GenericViewSet)一起使用：五个扩展类的需要调用GenericAPIView提供的序列化器与数据库查询的方法。

• 使用方法

class DepartmentListAPIView(ListModelMixin,CreateModelMixin,GenericAPIView):

    queryset = Department.objects.all()
    serializer_class = DepartmentSerializer

    def get(self,request):
        """查询多条数据"""
        return self.list(request)

    def post(self,request):
        """新增一条数据"""
        return self.create(request)

class DepartmentDetailAPIView(RetrieveModelMixin,UpdateModelMixin,DestroyModelMixin,GenericAPIView):

    queryset = Department.objects.all()
    serializer_class = DepartmentSerializer

    def get(self,request,pk):
        """查询一条数据"""
        return self.retrieve(request,pk)

    def post(self,request,pk):
        """修改部门"""
        return self.update(request,pk)

    def delete(self,request,pk):
        """删除一个部门"""
        return self.destroy(request,pk)

• 五个扩展类的源代码

"""
Basic building blocks for generic class based views.

We don't bind behaviour to http method handlers yet,
which allows mixin classes to be composed in interesting ways.
"""
from __future__ import unicode_literals

from rest_framework import status
from rest_framework.response import Response
from rest_framework.settings import api_settings

class CreateModelMixin(object):
    """
    Create a model instance.
    """
    def create(self, request, *args, **kwargs):
        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        self.perform_create(serializer)
        headers = self.get_success_headers(serializer.data)
        return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)

    def perform_create(self, serializer):
        serializer.save()

    def get_success_headers(self, data):
        try:
            return {'Location': str(data[api_settings.URL_FIELD_NAME])}
        except (TypeError, KeyError):
            return {}

class ListModelMixin(object):
    """
    List a queryset.
    """
    def list(self, request, *args, **kwargs):
        queryset = self.filter_queryset(self.get_queryset())

        page = self.paginate_queryset(queryset)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)

        serializer = self.get_serializer(queryset, many=True)
        return Response(serializer.data)

class RetrieveModelMixin(object):
    """
    Retrieve a model instance.
    """
    def retrieve(self, request, *args, **kwargs):
        instance = self.get_object()
        serializer = self.get_serializer(instance)
        return Response(serializer.data)

class UpdateModelMixin(object):
    """
    Update a model instance.
    """
    def update(self, request, *args, **kwargs):
        partial = kwargs.pop('partial', False)
        instance = self.get_object()
        serializer = self.get_serializer(instance, data=request.data, partial=partial)
        serializer.is_valid(raise_exception=True)
        self.perform_update(serializer)

        if getattr(instance, '_prefetched_objects_cache', None):
            # If 'prefetch_related' has been applied to a queryset, we need to
            # forcibly invalidate the prefetch cache on the instance.
            instance._prefetched_objects_cache = {}

        return Response(serializer.data)

    def perform_update(self, serializer):
        serializer.save()

    def partial_update(self, request, *args, **kwargs):
        kwargs['partial'] = True
        return self.update(request, *args, **kwargs)

class DestroyModelMixin(object):
    """
    Destroy a model instance.
    """
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()
        self.perform_destroy(instance)
        return Response(status=status.HTTP_204_NO_CONTENT)

    def perform_destroy(self, instance):
        instance.delete()