使用信号概念去做事件

Question

这是我在做一个记录在数据库中更新的时候发送邮件。我已经将接收器定义在一个名为listeners.py的单独文件中以接收信号。

signals.py

import django.dispatch 

send_email_to = django.dispatch.Signal() 

listeners.py

@receiver(send_mail_to) 
def send_update(sender, instance, created, **kwargs): 
    if instance.author_name: 
     message = "Book details has been updated" 
     subject = "Book updates" 
     send_mail(subject, message, settings.DEFAULT_FROM_EMAIL,[instance.email,]) 

post_save.connect(send_update, sender=Book) 

views.py

def addbook(request):  

    form = BookForm 

    if request.POST: 
     form = BookForm(request.POST) 

     if form.is_valid(): 
      cd = form.cleaned_data 
      form.save() 
      post_save.connect(send_update, sender=Book)  
      return redirect('/index/') 
    return render_to_response('addbook.html',{ 'form':form },context_instance=RequestContext(request)) 

我收到一条错误消息ahown以下。

NameError at /addbook/ 
global name 'send_update' is not defined 
Request Method: POST 
Request URL: http://localhost:8000/addbook/ 
Django Version: 1.4.3 
Exception Type: NameError 
Exception Value:  
global name 'send_update' is not defined 
Exception Location: /root/Samples/DemoApp/DemoApp/views.py in addbook, line 50 
Python Executable: /usr/bin/python 
Python Version: 2.7.0 
Python Path:  
['/root/Samples/DemoApp', 
'/usr/lib/python2.7/site-packages/distribute-0.6.28-py2.7.egg', 
'/usr/lib/python27.zip', 
'/usr/lib/python2.7', 
'/usr/lib/python2.7/plat-linux2', 
'/usr/lib/python2.7/lib-tk', 
'/usr/lib/python2.7/lib-old', 
'/usr/lib/python2.7/lib-dynload', 
'/usr/lib/python2.7/site-packages', 
'/usr/lib/python2.7/site-packages/PIL', 
'/usr/lib/python2.7/site-packages/gst-0.10', 
'/usr/lib/python2.7/site-packages/gtk-2.0', 
'/usr/lib/python2.7/site-packages/setuptools-0.6c11-py2.7.egg-info', 
'/usr/lib/python2.7/site-packages/webkit-1.0'] 
Server time: Sat, 23 Mar 2013 19:05:01 +0500 

任何人都可以看到会有什么问题。

感谢

Answer 1

因为你定义在你的看法有没有价值send_update。这就是为什么错误说你需要定义send_update。

但为什么你把post_save.connect(send_update, sender=Book)放在你的意见中？你必须删除它。它已经在listeners.py中理解了。因此，无论您使用Book模型执行什么操作，该模型都会向该信号发送请求。