【Django-rest-framework框架】第05回 视图集
目录
1. 两个视图基类
1.1 GenericAPIview属性和方法
属性：
serializer_class：指明视图使用的序列化器
方法：
get_serializer_class(self)：获取序列化类
get_serializer(self,*args,*kwargs)：该方法在提供序列化器对象的时候，会向序列化器对象的context属性补充三个数据：request、format、view，这三个数据对象可以在定义序列化器时使用。
request 当前视图的请求对象
view 当前请求的类视图对象
format 当前请求期望返回的数据格式
属性：
quesyset：指明使用的数据查询集
方法：
get_queryset(self)：获取序列化数据
get_objest(self)：根据lookup_field配置的参数获取单个对象
1. 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
2. filter_backends # 过滤类
3. pagination_class # 分页类
1.2 基于APIView写5个接口
from django.shortcuts import render
# Create your views here.
from rest_framework.views import APIView
from .models import User
from rest_framework.response import Response
from .serializer import UserSerializer
class UserView(APIView):
def get(self, request):
user_list = User.objects.all()
ser = UserSerializer(instance=user_list, many=True)
return Response(ser.data)
def post(self, request):
ser = UserSerializer(data=request.data)
if ser.is_valid():
ser.save()
return Response({'code': 100, 'msg': '新增成功'}, status=201)
else:
return Response({'code': 101, 'msg': ser.errors})
class UserDetailView(APIView):
def get(self, request, pk):
user = User.objects.filter(pk=pk).first()
ser = UserSerializer(instance=user)
return Response(ser.data)
def put(self, request, pk):
user = User.objects.filter(pk=pk).first()
ser = UserSerializer(instance=user, data=request.data)
if ser.is_valid():
ser.save()
return Response({'code': 100, 'msg': '修改成功'}, status=201)
else:
return Response({'code': 100, 'msg': ser.errors})
def delete(self, request, pk):
User.objects.filter(pk=pk).delete()
return Response('')
1.3 基于GenericAPIview写5个接口
from rest_framework.generics import GenericAPIView
class UserView(GenericAPIView):
queryset = User.objects.all()
serializer_class = UserSerializer
def get(self, request):
user_list = self.get_queryset()
ser = self.get_serializer(instance=user_list, many=True)
return Response(ser.data)
def post(self, request):
ser = self.get_serializer(data=request.data)
if ser.is_valid():
ser.save()
return Response({'code': 100, 'msg': '新增成功'}, status=201)
else:
return Response({'code': 101, 'msg': ser.errors})
class UserDetailView(GenericAPIView):
queryset = User.objects.all()
serializer_class = UserSerializer
def get(self, request, pk):
user = self.get_object()
ser = self.get_serializer(instance=user)
return Response(ser.data)
def put(self, request, pk):
user = self.get_object()
ser = self.get_serializer(instance=user, data=request.data)
if ser.is_valid():
ser.save()
return Response({'code': 100, 'msg': '修改成功'}, status=201)
else:
return Response({'code': 100, 'msg': ser.errors})
def delete(self, request, pk):
self.get_queryset().filter(pk=pk).delete()
return Response('')
2. 5个视图扩展类
必须配合GenericAPIView使用，不能配合APIView使用
CreateModelMixin: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
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
from rest_framework.generics import GenericAPIView
from rest_framework.mixins import RetrieveModelMixin, CreateModelMixin, UpdateModelMixin, DestroyModelMixin, \
ListModelMixin
class UserView(GenericAPIView, ListModelMixin, CreateModelMixin):
queryset = User.objects.all()
serializer_class = UserSerializer
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 UserDetailView(GenericAPIView, RetrieveModelMixin, UpdateModelMixin, DestroyModelMixin):
queryset = User.objects.all()
serializer_class = UserSerializer
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)
3. 9个视图子类
视图类:继承GenericAPIView+某个或某几个视图扩展类
from rest_framework.generics import ListAPIView,CreateAPIView, RetrieveAPIView,DestroyAPIView,UpdateAPIView
from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView,RetrieveUpdateAPIView,RetrieveDestroyAPIView
正常来讲 Destroy+Update 应该有一个，作者没加,可能没有应用场景
from rest_framework.generics import ListAPIView, CreateAPIView, RetrieveAPIView, DestroyAPIView, UpdateAPIView
from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView, RetrieveUpdateAPIView, \
RetrieveDestroyAPIView
class UserView(ListCreateAPIView):
queryset = User.objects.all()
serializer_class = UserSerializer
class UserDetailView(RetrieveUpdateDestroyAPIView):
queryset = User.objects.all()
serializer_class = UserSerializer
4. 视图集
继承ModelViewSet编写5个接口
视图类
from rest_framework.viewsets import ModelViewSet,ReadOnlyModelViewSet
class UserView(ModelViewSet):
queryset = User.objects.all()
serializer_class = UserSerializer
路由
path('user/', views.UserView.as_view({'get': 'list', 'post': 'create'})),
path('user/<int:pk>', views.UserView.as_view({'get': 'retrieve', 'put': 'update', 'delete': 'destroy'})),
5. 源码分析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)
1. 只要继承了ViewSetMixin，以后路由写法变量，都要协程：views.UserView.as_view({'get': 'list', 'post': 'create'}))
2. 这样写好以后，对应的请求方式来了，就会执行配置的方法
3. 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
6. 总结
#两个基类
APIView
GenericAPIView：有关数据库操作，queryset 和serializer_class
#5个视图扩展类(rest_framework.mixins)
CreateModelMixin：create方法创建一条
DestroyModelMixin：destory方法删除一条
ListModelMixin：list方法获取所有
RetrieveModelMixin：retrieve获取一条
UpdateModelMixin：update修改一条
#9个子类视图(rest_framework.generics)
CreateAPIView:继承CreateModelMixin,GenericAPIView，有post方法，新增数据
DestroyAPIView：继承DestroyModelMixin,GenericAPIView，有delete方法，删除数据
ListAPIView：继承ListModelMixin,GenericAPIView,有get方法获取所有
UpdateAPIView：继承UpdateModelMixin,GenericAPIView，有put和patch方法，修改数据
RetrieveAPIView：继承RetrieveModelMixin,GenericAPIView，有get方法，获取一条
ListCreateAPIView：继承ListModelMixin,CreateModelMixin,GenericAPIView，有get获取所有，post方法新增
RetrieveDestroyAPIView：继承RetrieveModelMixin,DestroyModelMixin,GenericAPIView，有get方法获取一条，delete方法删除
RetrieveUpdateAPIView：继承RetrieveModelMixin,UpdateModelMixin,GenericAPIView，有get获取一条，put，patch修改
RetrieveUpdateDestroyAPIView：继承RetrieveModelMixin,UpdateModelMixin,DestroyModelMixin,GenericAPIView，有get获取一条，put，patch修改，delete删除
#视图集
ViewSetMixin：重写了as_view
ViewSet： 继承ViewSetMixin和APIView
GenericViewSet：继承ViewSetMixin, generics.GenericAPIView
ModelViewSet：继承mixins.CreateModelMixin,mixins.RetrieveModelMixin,mixins.UpdateModelMixin,mixins.DestroyModelMixin,mixins.ListModelMixin,GenericViewSet
ReadOnlyModelViewSet：继承mixins.RetrieveModelMixin,mixins.ListModelMixin,GenericViewSet
7 继承关系画出来，有哪些常用属性或方法写出来
