Django REST框架：使用def update（）在ViewSet中不允许使用方法PUT [英] Django REST framework: method PUT not allowed in ViewSet with def update()

问题描述

在DRF中，我有一个像这样的简单ViewSet：

In DRF, I have a simple ViewSet like this one:

class MyViewSet(viewsets.ViewSet):       

    def update(self, request):
        # do things...
        return Response(status=status.HTTP_200_OK)

尝试PUT请求时，出现类似方法PUT的错误。如果我使用 def put（self，request）：一切正常。根据文档我应该使用 def update（）：而不是 def put（）：，为什么会发生？

When I try a PUT request, I get an error like method PUT not allowed. If I use def put(self, request): all things work fine. Accordingly to the docs I should use def update(): not def put():, why does it happen?

推荐答案

这是因为 APIView 没有为<$ c定义处理程序$ c> .put（）方法，因此传入的请求无法映射到视图上的处理程序方法，从而引发异常。

This is because the APIView has no handler defined for .put() method so the incoming request could not be mapped to a handler method on the view, thereby raising an exception.

（注意： viewsets.ViewSet 继承自 ViewSetMixin 和 APIView ）

APIView中的 dispatch（）方法检查是否为请求方法定义了方法处理程序。如果 dispatch（）方法找到请求方法的处理程序，它返回适当的响应。否则，它会引发异常 MethodNotAllowed 。

The dispatch() method in the APIView checks if a method handler is defined for the request method.If the dispatch() method finds a handler for the request method, it returns the appropriate response. Otherwise, it raises an exception MethodNotAllowed.

根据 dispatch（）方法的源代码， code> APIView 类：

As per the source code of dispatch() method in the APIView class:

def dispatch(self, request, *args, **kwargs):       
        ...
        ...    
        try:
            self.initial(request, *args, **kwargs)

            # Get the appropriate handler method
            if request.method.lower() in self.http_method_names:
                 # here handler is fetched for the request method
                 # `http_method_not_allowed` handler is assigned if no handler was found
                handler = getattr(self, request.method.lower(),
                                  self.http_method_not_allowed)
            else:
                handler = self.http_method_not_allowed 

            response = handler(request, *args, **kwargs) # handler is called here

        except Exception as exc:
            response = self.handle_exception(exc)

        self.response = self.finalize_response(request, response, *args, **kwargs)
        return self.response

由于在您的视图中未定义 .put（）方法处理程序，因此DRF调用后备处理程序 .http_method_not_allowed 。这会引发 MethodNotAllowed 异常。

Since .put() method handler is not defined in your view, DRF calls the fallback handler .http_method_not_allowed. This raises an MethodNotAllowed exception.

.http_method_not_allowed（）的源代码是：

def http_method_not_allowed(self, request, *args, **kwargs):
    """
    If `request.method` does not correspond to a handler method,
    determine what kind of exception to raise.
    """
    raise exceptions.MethodNotAllowed(request.method) # raise an exception 

定义 .put（）您认为吗？

Why it worked when you defined .put() in your view?

定义 def put（self，request ）：在您的视图中，DRF可以将传入的请求方法映射到视图上的处理程序方法。这导致返回了适当的响应而没有引发异常。

When you defined def put(self, request): in your view, DRF could map the incoming request method to a handler method on the view. This led to appropriate response being returned without an exception being raised.

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