视图--视图类
rest_framework.views.APIView
rest_framework.views.APIView
APIView
是REST framework提供的所有视图的基类,继承自Django的View
父类。
APIView
与View
的不同之处在于:
- 传入到视图方法中的是REST framework的
Request
对象,而不是Django的HttpRequeset
对象; - 视图方法可以返回REST framework的
Response
对象,视图会为响应数据设置(render)符合前端要求的格式; - 任何
APIException
异常都会被捕获到,并且处理成合适的响应信息; - 在进行dispatch()分发前,会对请求进行身份认证、权限检查、流量控制。
支持定义的属性:
- authentication_classes 列表或元组,身份认证类
- permissoin_classes 列表或元组,权限检查类
- throttle_classes 列表或元组,流量控制类
在APIView
中仍以常规的类视图定义方法来实现get() 、post() 或者其他请求方式的方法。
举例:
from rest_framework.views import APIView from rest_framework.response import Response # url(r'^books/$', views.BookListView.as_view()), class BookListView(APIView): def get(self, request): books = BookInfo.objects.all() serializer = BookInfoSerializer(books, many=True) return Response(serializer.data)
GenericAPIView
rest_framework.generics.GenericAPIView
继承自APIVIew
,主要增加了操作序列化器和数据库查询的方法,作用是为下面Mixin扩展类的执行提供方法支持。通常在使用时,可搭配一个或多个Mixin扩展类。
提供的关于序列化器使用的属性与方法
属性
方法
1、get_serializer_class(self)
def get_serializer_class(self): if self.request.user.is_staff: return FullAccountSerializer return BasicAccountSerializer
注意,该方法在提供序列化器对象的时候,会向序列化器对象的context属性补充三个数据:request、format、view,这三个数据对象可以在定义序列化器时使用。
-
request 当前视图的请求对象
-
view 当前请求的类视图对象
-
format
def get_queryset(self): user = self.request.user return user.accounts.all()
get_object(self)
返回详情视图所需的模型类数据对象,主要用来提供给Mixin扩展类使用。
在试图中可以调用该方法获取详情信息的模型类对象。
若详情访问的模型类对象不存在,会返回404。
该方法会默认使用APIView提供的check_object_permissions方法检查当前对象是否有权限被访问。
# url(r'^books/(?P<pk>\d+)/$', views.BookDetailView.as_view()), class BookDetailView(GenericAPIView): queryset = Book.objects.all() serializer_class = BookSerializer def get(self, request, pk): book = self.get_object() # get_object()方法根据pk参数查找queryset中的数据对象 serializer = self.get_serializer(book) return Response(serializer.data)
其他可以设置的属性
- pagination_class 指明分页控制类
- filter_backends 指明过滤控制后端
提供了几种后端视图(对数据资源进行曾删改查)处理流程的实现,如果需要编写的视图属于这五种,则视图可以通过继承相应的扩展类来复用代码,减少自己编写的代码量。
列表视图扩展类,提供list(request, *args, **kwargs)
方法快速实现列表视图,返回200状态码。
该Mixin的list方法会对数据进行过滤和分页。
源码:
class ListModelMixin(object): """ List a queryset. """ def list(self, request, *args, **kwargs): # 过滤 queryset = self.filter_queryset(self.get_queryset()) # 分页 page = self.paginate_queryset(queryset) if page is not None: serializer = self.get_serializer(page, many=True) return self.get_paginated_response(serializer.data) # 序列化 serializer = self.get_serializer(queryset, many=True) return Response(serializer.data)
from rest_framework.mixins import ListModelMixin class BookListView(ListModelMixin, GenericAPIView): queryset = Book.objects.all() serializer_class = BookSerializer def get(self, request): # get方法调用list方法实现查询列表 return self.list(request)
2、CreateModelMixin
创建视图扩展类,提供create(request, *args, **kwargs)
方法快速实现创建资源的视图,成功返回201状态码。
如果序列化器对前端发送的数据验证失败,返回400错误。
源码:
class CreateModelMixin(object): """ Create a model instance. """ def create(self, request, *args, **kwargs): # 获取序列化器 serializer = self.get_serializer(data=request.data) # 验证 serializer.is_valid(raise_exception=True) # 保存 self.perform_create(serializer) headers = self.get_success_headers(serializer.data) return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers) def perform_create(self, serializer): serializer.save() def get_success_headers(self, data): try: return {'Location': str(data[api_settings.URL_FIELD_NAME])} except (TypeError, KeyError): return {}
3、RetrieveModelMixin
详情视图扩展类,提供retrieve(request, *args, **kwargs)
方法,可以快速实现返回一个存在的数据对象。
class RetrieveModelMixin(object): """ Retrieve a model instance. """ def retrieve(self, request, *args, **kwargs): # 获取对象,会检查对象的权限 instance = self.get_object() # 序列化 serializer = self.get_serializer(instance) return Response(serializer.data)
举例:
class BookDetailView(RetrieveModelMixin, GenericAPIView): queryset = Book.objects.all() serializer_class = BookSerializer def get(self, request, pk): return self.retrieve(request)
4、UpdateModelMixin
更新视图扩展类,提供update(request, *args, **kwargs)
方法,可以快速实现更新一个存在的数据对象。
同时也提供
成功返回200,序列化器校验数据失败时,返回400错误。
源码
class UpdateModelMixin(object): """ Update a model instance. """ def update(self, request, *args, **kwargs): partial = kwargs.pop('partial', False) instance = self.get_object() serializer = self.get_serializer(instance, data=request.data, partial=partial) serializer.is_valid(raise_exception=True) self.perform_update(serializer) if getattr(instance, '_prefetched_objects_cache', None): # If 'prefetch_related' has been applied to a queryset, we need to # forcibly invalidate the prefetch cache on the instance. instance._prefetched_objects_cache = {} return Response(serializer.data) def perform_update(self, serializer): serializer.save() def partial_update(self, request, *args, **kwargs): kwargs['partial'] = True return self.update(request, *args, **kwargs)
5、DestroyModelMixin
删除视图扩展类,提供destroy(request, *args, **kwargs)
方法,可以快速实现删除一个存在的数据对象。
成功返回204,不存在返回404。
源码
class DestroyModelMixin(object): """ Destroy a model instance. """ def destroy(self, request, *args, **kwargs): instance = self.get_object() self.perform_destroy(instance) return Response(status=status.HTTP_204_NO_CONTENT) def perform_destroy(self, instance): instance.delete()
1、CreateAPIView
提供 post 方法
继承自: GenericAPIView、CreateModelMixin
class CreateAPIView(mixins.CreateModelMixin, GenericAPIView): """ Concrete view for creating a model instance. """ def post(self, request, *args, **kwargs): return self.create(request, *args, **kwargs)
2、ListAPIView
提供 get 方法
继承自:GenericAPIView、ListModelMixin
class ListAPIView(mixins.ListModelMixin, GenericAPIView): """ Concrete view for listing a queryset. """ def get(self, request, *args, **kwargs): return self.list(request, *args, **kwargs)
3、RetrieveAPIView
提供 get 方法
继承自: GenericAPIView、RetrieveModelMixin
class RetrieveAPIView(mixins.RetrieveModelMixin, GenericAPIView): """ Concrete view for retrieving a model instance. """ def get(self, request, *args, **kwargs): return self.retrieve(request, *args, **kwargs)
4、DestoryAPIView
提供 delete 方法
继承自:GenericAPIView、DestoryModelMixin
class DestroyAPIView(mixins.DestroyModelMixin, GenericAPIView): """ Concrete view for deleting a model instance. """ def delete(self, request, *args, **kwargs): return self.destroy(request, *args, **kwargs)
5、UpdateAPIView
提供 put 和 patch 方法
继承自:GenericAPIView、UpdateModelMixin
class UpdateAPIView(mixins.UpdateModelMixin, GenericAPIView): """ Concrete view for updating a model instance. """ def put(self, request, *args, **kwargs): return self.update(request, *args, **kwargs) def patch(self, request, *args, **kwargs): return self.partial_update(request, *args, **kwargs)
6、RetrieveUpdateAPIView
提供 get、put、patch方法
继承自: GenericAPIView、RetrieveModelMixin、UpdateModelMixin
class RetrieveUpdateAPIView(mixins.RetrieveModelMixin, mixins.UpdateModelMixin, GenericAPIView): """ Concrete view for retrieving, updating a model instance. """ 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 patch(self, request, *args, **kwargs): return self.partial_update(request, *args, **kwargs)
7、RetrieveUpdateDestoryAPIView
提供 get、put、patch、delete方法
继承自:GenericAPIView、RetrieveModelMixin、UpdateModelMixin、DestoryModelMixin
class RetrieveUpdateDestroyAPIView(mixins.RetrieveModelMixin, mixins.UpdateModelMixin, mixins.DestroyModelMixin, GenericAPIView): """ Concrete view for retrieving, updating or deleting a model instance. """ 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 patch(self, request, *args, **kwargs): return self.partial_update(request, *args, **kwargs) def delete(self, request, *args, **kwargs): return self.destroy(request, *args, **kwargs)
8、ListCreateAPIView
提供get方法和post方法
继承GenericAPIView、ListModelMixin、CreateModelMixin
class ListCreateAPIView(mixins.ListModelMixin, mixins.CreateModelMixin, GenericAPIView): """ Concrete view for listing a queryset or creating a model instance. """ def get(self, request, *args, **kwargs): return self.list(request, *args, **kwargs) def post(self, request, *args, **kwargs): return self.create(request, *args, **kwargs)