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

问题描述

我正在使用 DRF 构建 API，并且我使用了一个主类对基于类的视图进行了一些验证:

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
        # ...

验证失败，至少有一个，但正在执行数据库事务，我实际上从 dispatch 方法得到了一条错误消息的响应，但是 post 方法是在 dispatch 之前执行，我使用断点来查看流程，这是进入 post 方法然后进入 dispatch 方法，就像他们是分开的线程.

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.

来自文档:

as_view 入口点创建类的实例并调用它的 dispatch() 方法.dispatch 查看请求以确定是否是 GET、POST 等，并将请求中继到匹配的如果定义了方法，则为方法，否则引发 HttpResponseNotAllowed.

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.

所以我想如果我在dispatch中返回一个错误的响应，post方法不应该被执行，为什么它会被执行?我在这里做错了什么?

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?

推荐答案

由于您没有提供调度方法代码，因此只能是猜测.我的 2 美分是你在某个时候调用 MasterClass 的 super，它会调用 APIView 调度，它会调用你的 POST.

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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