【转帖+改造】django HTTP Request 的调用层次

Django开发总结

2013-01-13

fromhttp://kasicass.blog.163.com/blog/static/3956192009510115226144/

django.core.management.base.py,commands的基类，定义了几个基础接口

django.core.management.[commands],里面实现了startproject,runserver等所有的commands

django.core.management.__init__.py中的execute_manager()是所有逻辑的入口。

python manager.py runserver ip:port ==>
  django.core.management.__init__.py
    django.core.management.commands.runserver.py
      django.core.servers.basehttp.run()
        httpd = WSGIServer(server_address, WSGIRequestHandler)
        httpd.set_app(wsgi_handler)  # wsgi_handler = AdminMediaHandler(WSGIHandler(), path)
        httpd.serve_forever()        # django.core.handlers.wsgi.WSGIHandler

http request =>
  django.core.servers.basehttp.WSGIRequestHandler.handle()
    django.core.servers.basehttp.ServerHandler.run()
      django.core.servers.basehttp.AdminMediaHandler.__call__()
        django.core.handlers.wsgi.WSGIHandler.__call__()
          request = self.request_class(environ)     【1】
          response = self.get_response(request)      【2】
            django.core.handlers.base.BaseHandler.get_response()
              resolver = urlresolvers.RegexURLResolver(r'^/', urlconf)
              callback, callback_args, callback_kwargs = resolver.resolve(request.path_info)
              response = callback(request, *callback_args, **callback_kwargs)

    django.core.servers.basehttp.ServerHandler.run(), response 会被一路 return，到达这里后，拼接，再发回给浏览器。

我们的小程序helloworld.index()就是上面的callback函数。

-------------------------------------------------

#urls.py

urlpatterns = patterns('',
    (r'^hello/$', 'foobar.helloworld.index'),
)

-------------------------------------------------

#helloworld.py

from django.http import HttpResponse
def index(request):
    return HttpResponse("Hello Django!")

-------------------------------------------------

WSGI是啥，看：

http://cvs.woodpecker.org.cn/svn/woodpecker/pureprolog/trunk/essay/wsgiinto/wsgi_into.html

http://wiki.python.org/moin/WSGIImplementations

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//我的注释：奇怪吗，在上面生成response的过程当中，又再次生成了request，看上面的【1】，原因在于：我们对request对象当中进行的一些参数设置，要反馈到response当中去，比如cookie和session，这也不难理解为什么下面这样的代码，把我们设置的session给回传给客户端了

def login(request): 
      m = Member.objects.get(username=request.POST['username']) 
     if m.password == request.POST['password']: 
         request.session['member_id'] = m.id 
         return HttpResponse("You're logged in.") 
     else: 
         return HttpResponse("Your username and password didn't match.")

viahttp://docs.djangoproject.com/en/dev/topics/http/sessions/

django wsgi core