两个视图基类，五个视图扩展类

• 两个视图基类

• 五个视图扩展类

---

两个视图基类

# 之前写5个接口，继承APIView
# 还可以继承GenericAPIView：它帮我们干了好多事

# GenericAPIView:属性和方法
	-属性
    	-queryset    # 要序列化的数据
    	-serializer_class # 序列化类
        -----了解------
        -lookup_field  # 通过get_object  获取单个对象的查询key值，value值是路由中传进来的
        -filter_backends  # 过滤类
        -pagination_class # 分页类
    -方法
    	-get_queryset # 获取要序列化的数据
        -get_object   # 根据lookup_field配置的参数获取单个对象
        -get_serializer # 获取序列化类，咱们直接用的
        
        -get_serializer_class # 获取序列化类，不是咱们直接用的get_serializer调用了它
        -------了解-----
        -filter_queryset # 跟过滤有关系
        -paginate_xxx    # 跟分页有关

                                           

---

五个视图扩展类

必须配合GenericAPIView使用，不能配合APIView使用

# RetrieveModelMixin:写了一个Create方法，就是原来咱们post中的代码
# RetrieveModelMixin：retrieve，就是咱们原来的get
# UpdateModelMixin：update方法，就是咱们原来的put
# ListModelMixin：list方法，就是原来咱们的get
# DestroyModelMixin：destroy方法，就是原来咱们的delete

基于GenericAPIView+5个视图扩展类编写5个接口

views.py

from .models import Publish
from .serializer import PublishModelSerializer
from rest_framework.generics import GenericAPIView
from rest_framework.mixins import RetrieveModelMixin, CreateModelMixin, UpdateModelMixin, DestroyModelMixin, \
    ListModelMixin


class PublishView(GenericAPIView, ListModelMixin, CreateModelMixin):
    queryset = Publish.objects.all()
    serializer_class = PublishModelSerializer

    def get(self, request, *args, **kwargs):
        return self.list(request, *args, **kwargs)

    def post(self, request, *args, **kwargs):
        return self.create(request, *args, **kwargs)


class PublishDetailView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
    queryset = Publish.objects.all()
    serializer_class = PublishModelSerializer

    def get(self, request, *args, **kwargs):
        return self.retrieve(request, *args, **kwargs)

    def Put(self, request, *args, **kwargs):
        return self.update(request, *args, **kwargs)

    def delete(self, request, *args, **kwargs):
        return self.destroy(request, *args, **kwargs)

 

9个视图子类

# 视图类:继承了GenericAPIView+某个或某几个视图扩展类

基于9个视图子类编写5个接口

views.py

from rest_framework.generics import ListAPIView, CreateAPIView, RetrieveAPIView, DestroyAPIView, UpdateAPIView
from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView, RetrieveDestroyAPIView, \
    RetrieveUpdateAPIView


class PublishView(ListCreateAPIView):
    queryset = Publish.objects.all()
    serializer_class = PublishModelSerializer


class PublishDetailView(RetrieveUpdateDestroyAPIView):
    queryset = Publish.objects.all()
    serializer_class = PublishModelSerializer

视图集

# 使用视图集ViewSet，可以将一系列逻辑相关的动作放到一个类中：

# list()                   提供一组数据
# retrieve()               提供单个数据
# create()                 创建数据
# update()                 保存数据
# destory()                删除数据
# ViewSet视图集类不再实现get()、post()等方法，而是实现动作 action 如 list() 、create() 等。

继承ModelViewSet编写5个接口

urls.py

from django.contrib import admin
from django.urls import path
from app01.views import PublishView

urlpatterns = [
    path('admin/', admin.site.urls),
    path('publish/', PublishView.as_view({'get': 'list', 'post': 'create'})),
    path('publish/<int:pk>/', PublishView.as_view({'get': 'retrieve', 'put': 'update', 'delete': 'destroy'}))
]

views.py

from rest_framework.viewsets import ModelViewSet, ReadOnlyModelViewSet


class PublishView(ModelViewSet):
    queryset = Publish.objects.all()
    serializer_class = PublishModelSerializer

ViewSetMixin源码分析

from rest_framework.viewsets import ViewSetMixin, ViewSet, GenericViewSet

# ViewSet: APIView+ViewSetMixin的组合
# ViewSetMixin: 控制了路由的写法
# GenericViewSet: GenericAPIView+ViewSetMixin的组

"""
ModelViewSet它继承了很多类，其中GenericViewSet继承了GenericAPIView+ViewSetMixin，而ViewSetMixin方法之所以能够控制路由，就是因为它重写了as_view
所以在路由配置中的as_view，其实已经不是APIview中的as_view了，这里的as_view就是ViewSetMixin方法的as_view

继承ViewSetMixin的as_view，是根据继承的查找顺序执行的   userview>>>>ModelViewSet>>>>GenericAPIView>>>>>ViewSetMixin

            mixins.CreateModelMixin,
            mixins.RetrieveModelMixin,
            mixins.UpdateModelMixin,
            mixins.DestroyModelMixin,
            mixins.ListModelMixin,
            GenericViewSet

"""
class ViewSetMixin:
    @classonlymethod
    def as_view(cls, actions=None, **initkwargs):
        # 路由中as_view中必须传参数，必须传字典：{'get': 'list', 'post': 'create'}
        if not actions: 
            raise TypeError("The `actions` argument must be provided when "
                            "calling `.as_view()` on a ViewSet. For example "
                            "`.as_view({'get': 'list'})`")
        # 路由匹配成功，执行view(request)，request是老的request
        def view(request, *args, **kwargs):
            # actions={'get': 'list', 'post': 'create'}
            for method, action in actions.items():
                # method:get      action:list
                # self 是视图类的对象中通过反射，查找list，
                # handler视图类中的list方法
                handler = getattr(self, action)
                # 向视图类的对象中，反射 method:get,handler:list方法
                # self.get=list
                setattr(self, method, handler)
            return self.dispatch(request, *args, **kwargs)
        return csrf_exempt(view)


# 只要继承了ViewSetMixin，路由写法就会变，都要写成：views.UserView.as_view({'get': 'list', 'post': 'create'}))
# 这样写好以后，对应的请求方式来了，就会执行配置的方法


# 扩展：
	-以后只要继承了ViewSetMixin，视图类中可以写任意名字的方法，不用非得写get，post，delete