day03---继承5大扩展类和五大子类

一:继承五大扩展类：

1：序列化返回多个模型类对象：（ListModelMixin）
1.1:ListModelMixin干了什么？？

1.2：所以继承之后的代码是：

class BooksView(GenericAPIView, ListModelMixin):

    # 定义类属性
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers

    # :序列化返回多个模型类对象
    def get(self, request):
        return self.list(request)

2：序列化新建单一资源：（CreateModelMixin）
2.1:CreateModelMixin做了啥？

2.2：继承后的代码：

class BooksView(GenericAPIView, ListModelMixin, CreateModelMixin):

    # 定义类属性
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers

    # :序列化返回多个模型类对象
    def get(self, request):
        return self.list(request)

    # 反序列化新建单一资源
    def post(self, request):
       return self.create(request)

3：反序列化单一资源：（RetriveModelMixin）
3.1:RetriveModelMixin做了什么？

3.2：继承后的代码：

class BookView(GenericAPIView, RetrieveModelMixin):

    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers
    lookup_field = "pk"
    lookup_url_kwarg = "pk"

    # 1：序列化返回单一资源
    def get(self, request, pk):
        return self.retrieve(request, pk)

4：反序列化更新：（UpdateModelMixin）
4.1：UpdateModelMixin做了什么？

4.2：继承之后的代码：

class BookView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin):

    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers
    lookup_field = "pk"
    lookup_url_kwarg = "pk"

    # 1：序列化返回单一资源
    def get(self, request, pk):
        return self.retrieve(request, pk)

    # 2：反序列化更新（全更新与部分更新）

    def put(self, request, pk):
        return self.update(request, pk)

    def patch(self, request, pk):
        return self.partial_update(request, pk)

5：反序列化删除单一资源：（DestroyModelMixin）
5.1：DestroyModelMixin做了什么？

5.2：继承之后的代码：

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

    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers
    lookup_field = "pk"
    lookup_url_kwarg = "pk"

    # 1：序列化返回单一资源
    def get(self, request, pk):
        return self.retrieve(request, pk)

    # 2：反序列化更新（全更新）

    def put(self, request, pk):
        return self.update(request, pk)

    def patch(self, request, pk):
        return self.partial_update(request, pk)

    # 3:删除单一资源
    def delete(self, request, pk):
        return self.destroy(request, pk)

此时我们发现，只剩下视图函数，那么与没有不用写视图函数的呢？

二：五大子类：

from books.models import BookInfo
from serializers import BookInfoModelSerializers
from rest_framework.generics import ListAPIView, CreateAPIView
from rest_framework.generics import RetrieveAPIView,UpdateAPIView, DestroyAPIView

class BooksView(ListAPIView, CreateAPIView):
    # 定义类属性
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers
    
class BookView(RetrieveAPIView, ListAPIView, CreateAPIView, UpdateAPIView, DestroyAPIView):

    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers
    lookup_field = "pk"
    lookup_url_kwarg = "pk"

三：视图集ViewSetMixin：

功能：django默认get请求，找get方法，能不能有一种途径，能够让get方法找我们自定义的方法呢？

案例一：
1：定义一个视图：

from rest_framework.viewsets import ViewSetMixin

from books.models import BookInfo
from serializers import BookInfoModelSerializers


class BookView(ViewSetMixin, GenericAPIView):

    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers

    def mylist(self, request, *args, **kwargs):
        books = self.get_queryset()
        serializer = self.get_serializer(instance=books, many=True)
        return Response(data=serializer.data)

2：配置路由：

 re_path(r"^books/$", BookView.as_view({"get": "mylist"}))

案例二：ModelViewSet的使用：
modelsViewSet的继承关系：
源码分析：ViewSetMixin:可以自定义的视图集，GenericAPIView是继承于APIview的基类。所以ModelViewSet是我们所有类的子类，继承所有类。

from rest_framework.viewsets import ViewSetMixin, ModelViewSet
from books.models import BookInfo
from serializers import BookInfoModelSerializers
class BookView(ModelViewSet):
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers

路由：

urlpatterns = [
    path('admin/', admin.site.urls),
    re_path(r"^books/$", BookView.as_view({"get": "list", "post": "create"})),
    re_path(r"^books/(?P<pk>\d+)/$", BookView.as_view({
        "get": "retrieve",
        "put": "update",
        "patch": "partial_update",
        "delete": "destroy",
    }))
]

四：ReadOnlyModelViewSet:

五：ViewSet:

六：自定义视图函数：

from rest_framework.response import Response
from rest_framework.viewsets import  ModelViewSet

from books.models import BookInfo
from serializers import BookInfoModelSerializers
class BookView(ModelViewSet):
    queryset = BookInfo.objects.all()
    serializer_class = BookInfoModelSerializers

    def latest(self, request, *args, **kwargs):
        book = self.queryset.latest('bpub_date')
        serializers = self.get_serializer(instance=book)
        return Response(data=serializers.data)

urlpatterns = [
    path('admin/', admin.site.urls),
    re_path(r"^books/$", BookView.as_view({"get": "list", "post": "create"})),
    re_path(r"^books/(?P<pk>\d+)/$", BookView.as_view({
        "get": "retrieve",
        "put": "update",
        "patch": "partial_update",
        "delete": "destroy",
    })),

    re_path(r"^books/latest/$", BookView.as_view({"get": "latest"}))
]