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
"""