Django-rest-framework --- drf视图的详解

"""
""" 视图家族
views:视图类 - APIView,GenericAPIView(generics中)
mixins:视图工具类 - CreateModelMixin,ListModelMixin,RetrieveModelMixin,UpdateModelMixin,DestroyModelMixin
generics:工具视图类 - 九个类
viewsets:视图集 - 两个视图集基类,两个视图集子类,一个工具类
"""
"""

APIView

views.py

from rest_framework.views import APIView
from rest_framework.response import Response
from .response import APIResponse
from . import models, serializers


class CarAPIView(APIView):
    # 群查
    def get(self, request, *args, **kwargs):
        car_query = models.Car.objects.filter(is_delete=False).all()
        car_ser = serializers.CarModelSerializer(instance=car_query, many=True)
        return APIResponse(results=car_ser.data)

serializer.py

from rest_framework import serializers
from . import models

class SponsorModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Sponsor
        fields = ('name', 'phone')

class CarModelSerializer(serializers.ModelSerializer):
    # sponsors = SponsorModelSerializer(many=True)  # 用子序列化完成外键,外键就不能参与反序列化
    class Meta:
        model = models.Car
        fields = ('name', 'price', 'brand_name', 'sponsor_list', 'brand', 'sponsors')
        extra_kwargs = {
            'brand': {
                'required': True,
                'write_only': True
            },
            'sponsors': {
                'required': True,
                'write_only': True
            },
        }

GenericsAPIView

view.py

from rest_framework.generics import GenericAPIView
class CarGenericAPIView(GenericAPIView):
    # 不能直接写到objects结束,因为objects结束时,不是QuerySet对象,而是Manager对象,但 .all() 和 .filter() 后一定是QuerySet对象
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer
    lookup_url_kwarg = 'pk'
    # 群查
    """
    def get(self, request, *args, **kwargs):
        # car_query = models.Car.objects.filter(is_delete=False).all()
        car_query = self.get_queryset()

        # car_ser = serializers.CarModelSerializer(instance=car_query, many=True)
        car_ser = self.get_serializer(car_query, many=True)

        return APIResponse(results=car_ser.data)
    """

    # 单查
    def get(self, request, *args, **kwargs):
        # pk = kwargs.get('pk')
        # car_obj = models.Car.objects.filter(is_delete=False).filter(pk=pk).first()
        car_obj = self.get_object()

        # car_ser = serializers.CarModelSerializer(car_obj)
        car_ser = self.get_serializer(car_obj)

        return APIResponse(results=car_ser.data)

serializer.py

from rest_framework import serializers
from . import models

class SponsorModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Sponsor
        fields = ('name', 'phone')

class CarModelSerializer(serializers.ModelSerializer):
    # sponsors = SponsorModelSerializer(many=True)  # 用子序列化完成外键,外键就不能参与反序列化
    class Meta:
        model = models.Car
        fields = ('name', 'price', 'brand_name', 'sponsor_list', 'brand', 'sponsors')
        extra_kwargs = {
            'brand': {
                'required': True,
                'write_only': True
            },
            'sponsors': {
                'required': True,
                'write_only': True
            },
        }

mixin视图工具类

views.py

# mixins视图工具类
from rest_framework.mixins import RetrieveModelMixin, ListModelMixin, CreateModelMixin
class CarReadCreateGenericAPIView(ListModelMixin, RetrieveModelMixin, CreateModelMixin, GenericAPIView):
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer
    lookup_url_kwarg = 'pk'
    # 群查
    # """
    def get(self, request, *args, **kwargs):
        # car_query = self.get_queryset()
        # car_ser = self.get_serializer(car_query, many=True)
        # return APIResponse(results=car_ser.data)
        return self.list(request, *args, **kwargs)
    # """

    # 单查
    """
    def get(self, request, *args, **kwargs):
        # car_obj = self.get_object()
        # car_ser = self.get_serializer(car_obj)
        # return APIResponse(results=car_ser.data)
        response = self.retrieve(request, *args, **kwargs)
        return APIResponse(results=response.data)
    """

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

Generics工具视图类

views.py

# Generics工具视图类

# 单独完成单查接口
from rest_framework.generics import RetrieveAPIView
class CarRetrieveAPIView(RetrieveAPIView):
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer
    lookup_url_kwarg = 'pk'

# 单独完成群查接口
from rest_framework.generics import ListAPIView
class CarListAPIView(ListAPIView):
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer


# 单查(get)、单整体改(put)、单局部改(patch)、单删接口(delete)
from rest_framework.generics import RetrieveUpdateDestroyAPIView
class CarRetrieveUpdateDestroyAPIView(RetrieveUpdateDestroyAPIView):
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer

视图集

views.py

from rest_framework.views import APIView
from rest_framework.response import Response
from .response import APIResponse
from . import models, serializers

# 视图集
from rest_framework.viewsets import ViewSetMixin, GenericViewSet, ViewSet, ModelViewSet
class CarReadOnlyAPIView(RetrieveModelMixin, ListModelMixin, GenericViewSet):
    # def many_get(self, request, *args, **kwargs):
    #     return self.list(request, *args, **kwargs)
    #
    # def single_get(self, request, *args, **kwargs):
    #     return self.retrieve(request, *args, **kwargs)

    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer


# 六大接口
class CarModelViewSet(ModelViewSet):
    queryset = models.Car.objects.filter(is_delete=False).all()
    serializer_class = serializers.CarModelSerializer
    # 分析:从实际开发角度分析不合理点
    # 1)没有群增,群整体改,群局部改,群删四个接口
    # 2)删除操作视图集默认走的destroy方法是将资源从数据库中删除,通常一个做字段is_delete字段修改表示删除
    # 3)响应的结果只有数据,没有数据状态码和状态信息

    # 解决1,
    # 群整体改,群局部改,全删三个接口可以独立成三个方法
    def many_update(self, request, *args, **kwargs):
        return APIResponse(msg='这个地方是群整体改,你会写!')
    def many_partial_update(self, request, *args, **kwargs):
        return APIResponse(msg='这个地方是群局部改,你会写!')
    def many_destroy(self, request, *args, **kwargs):
        return APIResponse(msg='这个地方是群删,你会写!')
    # 群增与单增必须公用一个接口,都要走create方法 - 重写create方法,用逻辑进行拆分
    def create(self, request, *args, **kwargs):
        request_data = request.data
        if isinstance(request_data, list):
            car_ser = self.get_serializer(data=request_data, many=True)
            car_ser.is_valid(raise_exception=True)
            car_obj = car_ser.save()
            return APIResponse(msg='群增成功', results=self.get_serializer(car_obj, many=True).data)

        return super().create(request, *args, **kwargs)

    # 解决2,destroy方法是完成is_delete字段值修改 - 重写destroy方法,自定义实现体
    def destroy(self, request, *args, **kwargs):
        car_obj = self.get_object()
        car_obj.is_delete = True
        car_obj.save()
        return APIResponse(msg='删除成功')

    # 解决3,让群查有状态码和状态信息 - 重写list方法
    def list(self, request, *args, **kwargs):
        response = super().list(request, *args, **kwargs)
        return APIResponse(results=response.data)

serializer.py

from rest_framework import serializers
from . import models

class SponsorModelSerializer(serializers.ModelSerializer):
    class Meta:
        model = models.Sponsor
        fields = ('name', 'phone')

class CarModelSerializer(serializers.ModelSerializer):
    # sponsors = SponsorModelSerializer(many=True)  # 用子序列化完成外键,外键就不能参与反序列化
    class Meta:
        model = models.Car
        fields = ('name', 'price', 'brand_name', 'sponsor_list', 'brand', 'sponsors')
        extra_kwargs = {
            'brand': {
                'required': True,
                'write_only': True
            },
            'sponsors': {
                'required': True,
                'write_only': True
            },
        }

url.py

 url(r'^v7/cars/$', views.CarModelViewSet.as_view({
        'get': 'list',
        'post': 'create',
        'put': 'many_update',
        'patch': 'many_partial_update',
        'delete': 'many_destroy',
    })),
    url(r'^v7/cars/(?P<pk>d+)/$', views.CarModelViewSet.as_view({
        'get': 'retrieve',
        'put': 'update',
        'patch': 'partial_update',
        'delete': 'destroy',
    })),

总结

"""
1、APIView:
1)拥有View的所有  2)重写as_view  3)重写dispatch  4)一系列类属性

2、GenericAPIView
1)继承APIView,所以拥有APIView的所有
2)get_queryset方法,配置queryset类属性,提供视图类相关的Models
3)在第二条基础上,get_object方法,配置lookup_url_kwarg类属性,提供视图类相关的具体Model
4)get_serializer方法,配置serializer_class类属性,提供视图类相关的序列化对象

总结:GenericAPIView就是在APIView基础上额外提供了三个方法,三个类属性,如果不配合视图工具类,体现不出优势
目的:视图中的增删改查逻辑相似,但操作的资源不一致,操作资源就是操作 资源对象们、资源对象以及资源相关的序列化类,
将这三者形成配置,那操作逻辑就一致,就可以进行封装

3、mixins视图工具类们:五个类,六个方法
1)要配合GenericAPIView类使用,将单查、群查、单增,单整体改,单局部改,单删六个接口
封装成retrieve、list、create、update、partial_update、destroy六个方法
原因:六个方法的实现体,调用的方法就是GenericAPIView提供的,所以要配合GenericAPIView类使用

4、generics工具视图类们:九种组合
1)帮我们将不同个数不同种类的mixins与GenericAPIView进行组合
2)不同的组合帮我们实现好对应的get、post、put、patch、delete方法
3)需要我们自己配置三个类属性即可:queryset、serializer_class、lookup_url_kwarg

5.视图集总结
核心:视图集都继承了 ViewSetMixin类,该类重写了as_view方法,相比APIView的as_view方法,额外多出了一个参数actions
    as_view({'get': 'list'}) 传入的{'get': 'list'}就被actions介绍,原理是将get请求映射给视图类的list函数进行处理

1)为什么有GenericViewSet和ViewSet两个视图集基类
    GenericViewSet(ViewSetMixin, GenericAPIView),该分支严格满足资源接口
    ViewSet(ViewSetMixin, APIView),该分支满足的接口与资源Model类关系不是特别密切:登录接口、短信验证码接口

2)ReadOnlyModelViewSet,ModelViewSet两个视图集子类,就是做个一堆mixin与GenericViewSet相结合,
    自己在urls文件中配置as_view设置映射关系
"""
"""
class CarView(APIView):
    def get(self):
        obj,
        ser,
        response,
        
class CarView(GenericAPIView):  # 不会出现,中间产物
    queryset,
    serializer_class,
    lookup_url_kwarg,
    def get(self):
        obj,
        ser,
        response,

class CarView(RetrieveModelMixin, GenericAPIView):  # 自定义组合,可以超过九种
    queryset,
    serializer_class,
    lookup_url_kwarg,
    def get(self):
        self.retrieve()
        
class CarView(RetrieveAPIView):  # 最终产物,系统只提供了九种组合,RetrieveAPIView是其中一种
    queryset,
    serializer_class,
    lookup_url_kwarg,  
"""

路由分发

urls.py

# 当使用视图集的时候可以这样写
# 路由层:外面会遇到这种写法,看到了要认识
from rest_framework.routers import SimpleRouter
router = SimpleRouter()
router.register('v7/cars', views.CarModelViewSet, basename='car')  # cars后边没有"/"
# router.register('books', views.BookModelViewSet, basename='book')
# router.register('users', views.UserModelViewSet, basename='user')

urlpatterns = [
    url(r'', include(router.urls))
]

封装路由

from rest_framework.routers import Route, DynamicRoute, SimpleRouter as DRFSimpleRouter

class SimpleRouter(DRFSimpleRouter):
    routes = [
        # List route.  /资源s/
        Route(
            url=r'^{prefix}{trailing_slash}$',
            mapping={
                'get': 'list',  # 群查
                'post': 'create',  # 单增、群增
                'put': 'multiple_update',  # 群整改
                'patch': 'multiple_partial_update',  # 群局改
                'delete': 'multiple_destroy',  # 群删
            },
            name='{basename}-list',
            detail=False,
            initkwargs={'suffix': 'List'}
        ),
        # Dynamically generated list routes. Generated using
        # @action(detail=False) decorator on methods of the viewset.
        DynamicRoute(
            url=r'^{prefix}/{url_path}{trailing_slash}$',
            name='{basename}-{url_name}',
            detail=False,
            initkwargs={}
        ),
        # Detail route.  /资源s/(pk)/
        Route(
            url=r'^{prefix}/{lookup}{trailing_slash}$',
            mapping={
                'get': 'retrieve',  # 单查
                'put': 'update',  # 单整改
                'patch': 'partial_update',  # 单局改
                'delete': 'destroy'  # 单删
            },
            name='{basename}-detail',
            detail=True,
            initkwargs={'suffix': 'Instance'}
        ),
        # Dynamically generated detail routes. Generated using
        # @action(detail=True) decorator on methods of the viewset.
        DynamicRoute(
            url=r'^{prefix}/{lookup}/{url_path}{trailing_slash}$',
            name='{basename}-{url_name}',
            detail=True,
            initkwargs={}
        ),
    ]

# 对外提供十大接口的router对象
router = SimpleRouter()
# eg: router.register('users', UserModelViewSet, basename='user')
"""
/users/
'get': 'list',  # 群查
'post': 'create',  # 单增、群增
'put': 'multiple_update',  # 群整改
'patch': 'multiple_partial_update',  # 群局改
'delete': 'multiple_destroy',  # 群删

/users/(pk)/
'get': 'retrieve',  # 单查
'put': 'update',  # 单整改
'patch': 'partial_update',  # 单局改
'delete': 'destroy'  # 单删
"""

原文地址:https://www.cnblogs.com/whkzm/p/12142151.html