REST-framework快速构建API--源码解析

作者：@skyflask
转载本文请注明出处：https://www.cnblogs.com/skyflask/p/10422335.html

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目录

一、APIView
二、ModelView
三、认证、权限、频率源码

一、APIView

通过APIView实现API的过程如下：

urls.py

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1 2	url(r'^books/$', views.BookView.as_view(),name="books"),  url(r'^books/(\d+)/$', views.BookDetailView.as_view(),name="detailbook"),

 

views.py

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class BookView(APIView):     def get(self, request):         book_list = Book.objects.all()         bs = BookModelSerializers(book_list, many=True, context={'request': request})         return Response(bs.data)       def post(self, request):         # post请求的数据         bs = BookModelSerializers(data=request.data)         if bs.is_valid():             print(bs.validated_data)             bs.save()  # create方法             return Response(bs.data)         else:             return Response(bs.errors)     class BookDetailView(APIView):       def get(self, request, id):           book = Book.objects.filter(pk=id).first()         bs = BookModelSerializers(book, context={'request': request})         return Response(bs.data)       def put(self, request, id):         book = Book.objects.filter(pk=id).first()         bs = BookModelSerializers(book, data=request.data, context={'request': request})         if bs.is_valid():             bs.save()             return Response(bs.data)         else:             return Response(bs.errors)       def delete(self, request, id):         Book.objects.filter(pk=id).delete()           return Response()

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urls中，定义了两个url的请求方式：

• 通过URL：http://127.0.0.1/books/   GET/POST数据

• 通过URL：http://127.0.0.1/books/id/   GET/PUT/DELETE数据

第一种，url(r'^books/$', views.BookView.as_view(),name="books"),调用过程如下：

views.BookView.as_view()

　　1、APIView.as_view()，返回view，实际上是执行View.as_view()

　　　　2、View中的as_view()返回disptch()函数

　　　　　　3、self会从View类往上找dispatch()，在APIView类中有找到dispatch()

　　　　　　　　4、dispatch()会找get、post、put、delete等方法

　　　　　　　　　　5、在当前View下，BookView类下定义了get、post，BookDetailView类下定义了get、put、delete

　　　　　　　　　　　　6、执行当前类下的对应方法

第二种URL执行过程一样。

二、ModelView

通过ModelView实现API过程如下：

urls.py

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1 2	url(r'^authors/$', views.AuthorModelView.as_view({'get':'list','post':'create'}),name="authors"), url(r'^authors/$', views.AuthorModelView.as_view({'get':'retrieve','post':'update','delete':'destory'}),name="authors"),

views.py

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class AuthorModelView(viewsets.ModelViewSet):     queryset = Author.objects.all()     serializer_class = AuthorModelSerializers

执行过程如下：

1、当前类下没有as_view方法，从父类ModelViewSet中查找

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class ModelViewSet(mixins.CreateModelMixin,                    mixins.RetrieveModelMixin,                    mixins.UpdateModelMixin,                    mixins.DestroyModelMixin,                    mixins.ListModelMixin,                    GenericViewSet):     """     A viewset that provides default `create()`, `retrieve()`, `update()`,     `partial_update()`, `destroy()` and `list()` actions.     """     pass

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2、ModeViewSet在mixins中没有as_view,从GenericViewSet往上找

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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.     """     pass

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3、从ViewSetMixin中找到了as_view()，实际上返回了dispatch（）

ViewSetMixin==>generics.GenericAPIView==>views.APIView==>dispatch（）

4、执行dispatch（），实际上是找get、post、put、delete等方法

5、在当前类下找到对应的方法

 

 

三、认证、权限、频率源码

 通过ModelView方式实现认证,

局部应用：

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class AuthorModelView(viewsets.ModelViewSet):       authentication_classes = [TokenAuth, ]     queryset = Author.objects.all()     serializer_class = AuthorModelSerializers     pagination_class = StandardResultsSetPagination

　　

　　

全局应用：

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REST_FRAMEWORK={     "DEFAULT_AUTHENTICATION_CLASSES":["app01.utils.TokenAuth",],    }

　　

源码实现过程：

服务端以authors为例：

　1、在AuthorModelView中查找as_view()，在本类中找不到，往上查找；

　2、父类：viewsets.ModelViewSet

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class ModelViewSet(mixins.CreateModelMixin,                    mixins.RetrieveModelMixin,                    mixins.UpdateModelMixin,                    mixins.DestroyModelMixin,                    mixins.ListModelMixin,                    GenericViewSet):     """     A viewset that provides default `create()`, `retrieve()`, `update()`,     `partial_update()`, `destroy()` and `list()` actions.     """     pass

　　3、其他几个父类没有as_view（）和祖父类了，只能从GenericViewSet往上找；

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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.     """     pass

　　4、最左边父类ViewSetMixin查找as_view（），找到了

　　5、ViewSetMixin中的as_veiw()实际上返回了dispatch（）

　　6、再查找dispatch（）方法，顺序：generics.GenericAPIView==>APIView==>dispatch（）

　　

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def dispatch(self, request, *args, **kwargs):     """     `.dispatch()` is pretty much the same as Django's regular dispatch,     but with extra hooks for startup, finalize, and exception handling.     """     self.args = args     self.kwargs = kwargs     request = self.initialize_request(request, *args, **kwargs)     self.request = request     self.headers = self.default_response_headers  # deprecate?       try:         self.initial(request, *args, **kwargs)           # Get the appropriate handler method         if request.method.lower() in self.http_method_names:             handler = getattr(self, request.method.lower(),                               self.http_method_not_allowed)         else:             handler = self.http_method_not_allowed           response = handler(request, *args, **kwargs)       except Exception as exc:         response = self.handle_exception(exc)       self.response = self.finalize_response(request, response, *args, **kwargs)     return self.response

　　7、dispatch（）中，先会执行self.initial()

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def initial(self, request, *args, **kwargs):     """     Runs anything that needs to occur prior to calling the method handler.     """     self.format_kwarg = self.get_format_suffix(**kwargs)       # Perform content negotiation and store the accepted info on the request     neg = self.perform_content_negotiation(request)     request.accepted_renderer, request.accepted_media_type = neg       # Determine the API version, if versioning is in use.     version, scheme = self.determine_version(request, *args, **kwargs)     request.version, request.versioning_scheme = version, scheme       # Ensure that the incoming request is permitted     self.perform_authentication(request)     self.check_permissions(request)     self.check_throttles(request)

　　8、initial（）中会对过来的请求进行认证、授权、频率检测。

 

图标流程如下：