middleware (中间件)
是一个完整socket请求过程中必须经过的步骤 客户端发起request--->中间件request--->views处理--->中间件response--->客户端
如果在中间件中请求出错,则直接返回响应
作用:可以对所有请求做统一操作,也可以进行过滤
中间件的5个方法:
process_request
process_view
process_exception
process_exception
process_template_response
# 接收请求后首先经过process_request
def process_request(self, request):
print('请求1')
pass
# 当process_request处理完后,进行路由映射,再返回第一条继续进行处理
def process_view(self, request, callback, callback_args, callback_kwargs):
pass
# 当views处理完,且其中有错时,就会自动调用此方法,可返回给页面错误信息(没有错就不执行)(执行顺序是倒序,\
# 但如果和views最近的没有进行处理则往上查,查到后处理并返回最后一条进行process_response)
def process_exception(self, request, exception):
return HttpResponse('页面出错了!!!')
# 当views处理完成之后倒序的进行返回,所以必须要有return response
def process_response(self, request, response):
return response
# 如若views返回的内容中有render方法,则会执行
def process_template_response(self, request, response):
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MIDDLEWARE = [ # 'django.middleware.cache.UpdateCacheMiddleware', 'django.middleware.security.SecurityMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware', 'django.middleware.clickjacking.XFrameOptionsMiddleware', 'Middle.m1.Row1', 'Middle.m1.Row2', 'Middle.m1.Row3', # 'django.middleware.cache.FetchFromCacheMiddleware', ]
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from django.middleware.csrf import CsrfViewMiddleware from django.shortcuts import render,HttpResponse # from sg import pizza_done # pizza_done.send(sender='seven',toppings=123, size=456) # 写在需要触发的位置 class Row1(CsrfViewMiddleware): def process_request(self, request): pass print('请求...1') def process_view(self, request, callback, callback_args, callback_kwargs): # pass print('请求...4') def process_response(self, request, response): print('响应3') return response class Row2(CsrfViewMiddleware): def process_request(self, request): # pass print('请求...2') def process_view(self, request, callback, callback_args, callback_kwargs): # pass print('请求...5') def process_response(self, request, response): print('响应2') return response class Row3(CsrfViewMiddleware): def process_request(self, request): # pass print('请求...3') def process_view(self, request, callback, callback_args, callback_kwargs): # pass print('请求...6') def process_response(self, request, response): print('响应1') return response def process_exception(self, request, exception): # pass print(exception) return HttpResponse(exception)