DRF 通用视图-视图工具类-视图集以及路由

from rest_framework.views import APIView
from rest_framework.response import Response

from models import Goods
from serializers import GoodsSerializer


class GoodListView(APIView):
    def get(self, request):
        goods = Goods.objects.all()
        serializer = GoodsSerializer(goods, many=True)
        return Response(serializer.data)

class GoodsSerializer(serializers.ModelSerializer):
    # category = CategorySerializer()
    # images = GoodsImageSerializer(many=True)
    class Meta:
        model = Goods
        fields = "__all__"

def get_serializer(self, *args, **kwargs):
    """
    Return the serializer instance that should be used for validating and
    deserializing input, and for serializing output.

    返回应该用于验证和反序列化输入以及序列化输出的序列化器实例。
    """
    serializer_class = self.get_serializer_class()
    kwargs['context'] = self.get_serializer_context()
    return serializer_class(*args, **kwargs)

class GoodGenericAPIView(GenericAPIView):
    queryset = models.Good.objects.filter(is_delete=False)
    serializer_class = serializers.GoodModelSerializer
    lookup_field = 'pk'  # 先定义好，单查可以使用，默认是pk  自定义主键的有名分组，如果路由有名分组不是pk,这个属性就要自己设置了
    
    # 群取
    def get(self, request, *args, **kwargs):
        good_query = self.get_queryset()  # 获取queryset数据（model查询数据）
        good_ser = self.get_serializer(good_query, many=True)
        good_data = good_ser.data
        return APIResponse(results=good_data)

    # # 单取
    # def get(self, request, *args, **kwargs):
    #     good_query = self.get_object()
    #     good_ser = self.get_serializer(good_query)
    #     good_data = good_ser.data
    #     return APIResponse(results=good_data)

urlpatterns = [
    path('v2/goods/', views.GoodGenericAPIView.as_view()),
    path('v2/goods/<pk>/', views.GoodGenericAPIView.as_view()),
]

from rest_framework.mixins import ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin

class GoodMixinGenericAPIView(ListModelMixin, CreateModelMixin, RetrieveModelMixin, UpdateModelMixin, GenericAPIView):
    # GenericAPIView提供的序列化器和查询的数据
    queryset = models.Good.objects.filter(is_delete=False)
    serializer_class = serializers.GoodModelSerializer

    # 单查和群查
    def get(self, request, *args, **kwargs):
        if 'pk' in kwargs:
            # 单查  RetrieveModelMixin方法
            response = self.retrieve(request, *args, **kwargs)
        else:
            # mixins提供的list方法的响应对象是Response，将该对象格式化为自定义的APIResponse
            response = self.list(request, *args, **kwargs)  # 群查 ListModelMixin
        # response的数据都存放在response.data中
        return APIResponse(results=response.data)

    # 单增
    def post(self, request, *args, **kwargs):
        response = self.create(request, *args, **kwargs)    # CreateModelMixin方法
        return APIResponse(results=response.data)

    # 单整体修改
    def put(self, request, *args, **kwargs):
        response = self.update(request, *args, **kwargs)    # UpdateModelMixin
        return APIResponse(results=response.data)

    # 单局部修改
    def patch(self, request, *args, **kwargs):
        response = self.partial_update(request, *args, **kwargs)
        return APIResponse(results=response.data)

urlpatterns = [
    path('v3/goods/', views.GoodMixinGenericAPIView.as_view()),
    path('v3/goods/<pk>/', views.GoodMixinGenericAPIView.as_view()),
]

# 表示 get 请求会交给 my_get_list 视图函数处理
path('v5/books/', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),

urlpatterns = [
    # View的as_view()：将get请求映射到视图类的get方法
    # ViewSet的as_view({'get': 'my_get_list'})：将get请求映射到视图类的my_get_list方法
    path('v5/books/', views.BookGenericViewSet.as_view({'get': 'my_get_list'})),
    path('v5/books/<pk>/', views.BookGenericViewSet.as_view({'get': 'my_get_obj'})),
]

from rest_framework.viewsets import GenericViewSet
from rest_framework import mixins  #工具集 可以使用list, retrieve等方法

class BookGenericViewSet(RetrieveModelMixin, ListModelMixin, GenericViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

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

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

# viewsets.py
class GenericViewSet(ViewSetMixin, generics.GenericAPIView):
    """
    The GenericViewSet class does not provide any actions by default,
    but does include the base set of generic view behavior, such as
    the `get_object` and `get_queryset` methods.
    默认情况下，GenericViewSet类不提供任何操作，但是包含通用视图行为的基本集，比如get ohiect和get queryset方法
    """
    pass

# generics.py
class GenericAPIView(views.APIView):
    # ...

# vies.py
class APIView(View):
    # ...

class ViewSet(ViewSetMixin, views.APIView):
    """
    The base ViewSet class does not provide any actions by default.
    默认情况下，基本ViewSet类不提供任何操作。
    """
    pass

# vies.py
class APIView(View):
    # ...

urlpatterns = [
    path('v6/books/', views.BookModelViewSet.as_view({'get': 'list', 'post': 'create'})),
    path('v6/books/<pk>/', views.BookModelViewSet.as_view({'get': 'retrieve', 'put': 'update', 'patch': 'partial_update', 'delete': 'destroy'})),
]

class BookModelViewSet(ModelViewSet):
    queryset = models.Book.objects.filter(is_delete=False)
    serializer_class = serializers.BookModelSerializer

    # 删不是数据库，而是该记录中的修改is_delete的值，因此重写默认的destroy函数
    def destroy(self, request, *args, **kwargs):
        instance = self.get_object()          # type: models.Book
        if not instance:
            return APIResponse(1, '删除失败')  # 实际操作，在此之前就做了判断
        instance.is_delete = True
        instance.save()
        return APIResponse(0, '删除成功')

from django.urls import path, include
from rest_framework.routers import SimpleRouter
from . import views

router = SimpleRouter()
# 所有路由与ViewSet视图类的都可以注册，会产生 'v7/books/' 和 'v7/books/<pk>/'
router.register('v7/books', views.BookModelViewSet)

urlpatterns = [
    # router.urls 添加方法一
    # path('', include(router.urls)),
]

# router.urls 添加方法二
# urlpatterns += router.urls