中间件
django 中的中间件(middleware),在django中,中间件其实就是一个类,在请求到来和结束后,django会根据自己的规则在合适的时机执行中间件中相应的方法。
在django项目的settings模块中,有一个 MIDDLEWARE_CLASSES 变量,其中每一个元素就是一个中间件,如下图。
与mange.py在同一目录下的文件夹 wupeiqi/middleware下的auth.py文件中的Authentication类
中间件中可以定义四个方法,分别是:
process_request(self,request)
process_view(self, request, callback, callback_args, callback_kwargs)
process_template_response(self,request,response)
process_exception(self, request, exception)
process_response(self, request, response)
以上方法的返回值可以是None和HttpResonse对象,如果是None,则继续按照django定义的规则向下执行,如果是HttpResonse对象,则直接将该对象返回给用户。
自定义中间件
1、创建中间件类
class RequestExeute(object):
def process_request(self,request):
pass
def process_view(self, request, callback, callback_args, callback_kwargs):
i =1
pass
def process_exception(self, request, exception):
pass
def process_response(self, request, response):
return response
2、注册中间件
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'wupeiqi.middleware.auth.RequestExeute',
)
views:
####################################### class Foo: def __init__(self,req,html,dic): self.req = req self.html = html self.dic = dic def render(self): # // 创建钩子 return render(self.req,self.html,self.dic) def test(request,nid): print('小姨妈-->没带钱') # return render(request, 'index.html', {...}) return Foo(request, 'index.html', {'k1': 'v1'})
/Middle.m1
from django.utils.deprecation import MiddlewareMixin class Row1(MiddlewareMixin): def process_request(self,request): print('王森') def process_view(self, request, view_func, view_func_args, view_func_kwargs): print('张欣彤') def process_response(self, request, response): print('扛把子') return response from django.shortcuts import HttpResponse class Row2(MiddlewareMixin): def process_request(self,request): print('程毅强') # return HttpResponse('走') def process_view(self, request, view_func, view_func_args, view_func_kwargs): print('张需要') def process_response(self, request, response): print('侯雅凡') return response class Row3(MiddlewareMixin): def process_request(self,request): print('刘东') def process_view(self, request, view_func, view_func_args, view_func_kwargs): print('邵林') def process_response(self, request, response): print('连之泪') return response def process_exception(self, request, exception): if isinstance(exception,ValueError): return HttpResponse('出现异常》。。') def process_template_response(self,request,response): # 如果Views中的函数返回的对象中,具有render方法 print('-----------------------') return response
utl.py
path('test/(?P<nid>\d+)$', views.test),
setting.py
MIDDLEWARE = [ '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', ]