Django - DRF - 调度方法流程 [英] Django - DRF - dispatch method flow

问题描述

我正在与DRF建立一个API，我使用一个主类来对我的基于类的视图进行一些验证：

  class MasterClass（APIView）：
 
 def dispatch（self，request，* args，** 
 response = super（FaveoAPIView，self）.dispatch（request，* args，** 
＃我调用super，因为我需要访问请求数据
＃< some validationments here> 
＃如果验证失败，返回一个错误消息的JsonResponse 
 
 class MyView（MasteClass）：
 
 def post（self，request，* args，** kwargs）：
＃在这一点上，请求是：< WSGIRequest：POST'/ api / path /'> 
＃一些DB事务
＃... 
  

验证失败，至少有一个，但DB事务正在执行，我实际上收到一条来自 dispatch 方法的错误消息的响应，但 post 方法在 dispatch 之前执行，我使用断点查看流程，这将进入 post 方法，然后到 dispatch 方法，如他们是分开的线程。

从 docs ：

as_view入口点创建一个类的实例，并调用
它的dispatch（）方法。调度查看请求以确定
是否是GET，POST等，并将请求中继到匹配的
方法（如果已定义），或者引发HttpResponseNotAllowed（如果不是）。

所以我以为如果我在调度中返回一个错误的回复，那么不应该执行post方法，为什么要被执行？我在这里做错了什么？

解决方案

由于您没有提供调度方法代码，只会被猜测。
我的2美分是你在某个时候调用MasterClass的超级，这将调用APIView调度，这将调用你的POST。

I am working with DRF to build an API and I used a master class to do some validations to my class based views:

class MasterClass(APIView):

    def dispatch(self, request, *args, **
        response = super(FaveoAPIView, self).dispatch(request, *args, **kwargs)
        # I call super because I need access to request data.
        # <some validations here>
        # Return a JsonResponse with an error message if validations fails

class MyView(MasteClass):

    def post(self, request, *args, **kwargs):
        # At this point request is: <WSGIRequest: POST '/api/path/'>
        # some DB transaction
        # ...

Validations are failing, at least one, but the DB transaction is being executed, I actually get a response with an error message from dispatch method, but post method is executed before dispatch, I use breakpoints to view the flow, and this is going into the post method and then to dispatch method, like if they were separated threads.

From docs:

The as_view entry point creates an instance of your class and calls its dispatch() method. dispatch looks at the request to determine whether it is a GET, POST, etc, and relays the request to a matching method if one is defined, or raises HttpResponseNotAllowed if not.

So I thought that if I return a response with an error in dispatch, post method shouldn't be executed, why is it being executed? What am I doing wrong here?

解决方案

Since you didn't provide the dispatch method code it'll just be guesses. My 2 cents is that you're calling MasterClass's super at some point which will call the APIView dispatch which will call your POST.

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