Python - Django - Middleware process_view

Process_view execution order is also in order to perform settings.py

After urls.py process_view correspondence relationship, the functions performed before view

If it returns None, proceed to the back of the middleware functions process_view

If the HttpResponse returns, subsequent process_view function is not performed, skip to a function execution process_response

middleware_test.py：

Import MiddlewareMixin django.utils.deprecation from 
from django.shortcuts Import HttpResponse 


class the Test (MiddlewareMixin): 
    DEF process_request (Self, Request): 
        Print ( "It is a middleware -> the Test") 

    DEF process_response (Self, Request, the Response ): 
        Print ( "this is the Test of HttpResponse") 
        return HttpResponse ( "this is a Test return HttpResponse") 

    DEF process_view (Self, Request, view_func, view_args, view_kwargs): 
        '' ' 
        : param Request: browser sent request request object 
        : param view_func: the name of the view function to be performed 
        : param view_args: location parameter view function to be performed 
        : param view_kwargs: keywords view function to be executed 
        : return: 
        '''
        print ( "This is the Test of process_view function") 
        Print (view_func, of the type (view_func)) 


class Test2 (MiddlewareMixin): 
    DEF process_request (Self, Request): 
        print ( "This is a middleware -> test2") 

    DEF process_response (Self, Request, the Response): 
        Print ( "here Test2's HttpResponse") 
        return HttpResponse ( "this is the Test2 return HttpResponse") 

    DEF process_view (selfm, Request, view_func, view_args, view_kwargs): 
        Print ( "this is the Test2 the process_view function ") 
        Print (view_func, of the type (view_func))

views.py：

django.shortcuts Import HttpResponse from 


DEF index (Request): 
    Print ( "This is the index page") 
    return HttpResponse ( "Here is the main page index")

Visit, http: //127.0.0.1: 8000 / index /

 

operation result:

 

 

Implementation process:

Process_request function is performed first, and then perform process_view function before performing the function view, and then execute the view function, a function performed last process_response

 

process_request only returns None, after have been performed, it matches the route, find the view function to be executed, the first execution middleware process_view function before performing the function view

If after return process_view None, continuing with the subsequent method process_view middleware, after executing all of the functions executed view function process_view

If there is a process_view returned HttpResponse, do not perform subsequent process_view function, it will jump to the first process_response function, and continue down

For example, the intermediate return the HttpResponse process_view 3, no longer perform the subsequent intermediate 4,5,6 middleware, the middleware process_response direct jump function 6, and then perform intermediate 5,4,3, 2,1

 

If there process_request function returns HttpResponse object, do not perform subsequent process_request function is not performed process_view function, jump to the corresponding function is executed process_response