为什么Django post_save信号给我pre_save数据？

问题描述

我试图将一个信息对象连接到许多客户（见下面的代码）

当一个Information对象更新时，我想发送电子邮件每个客户连接到信息。

但是，当我记录信号接收的sold_to字段时，我总是在保存之前获取数据。 p>

我猜这是因为它的ManyToManyField和数据存储在一个单独的表中，但是不应该在所有关系更新后调用post_save信号？ p>

任何人都有解决方案的建议？

  class Customer 
 name = models.CharField（max_length = 200）
 category = models.ManyToManyField（'Category'，symmetric = False）
 contact = models.EmailField（）
 
类信息
 name = models.CharField（max_length = 200）
 email = models.EmailField（max_length = 200）
 mod_date = models.DateTimeField（auto_now = True） 
 sold_to = models.ManyToManyField（Customer，null = True，blank = True）
 
 
 def send_admin_email（sender，instance，signal，* args，** kwargs）：
 from myapp import settings 
 for cust in instance.sold_to.all（）：
 settings.debug（cust.name）
 
 post_save.connect（send_admin_email，sender =信息）
  

编辑：#django中的apollo13提醒我：
相关项目这些东西被保存到多对多关系中）
不像您发现的那样保存为模型的保存方法的一部分。 -

但是从2006年7月9日起，我真的很希望有一个解决方案。

解决方案

您正在面对的问题有一张公开的机票。您可以随时关注它，使其成为发布版本，或者您可以尝试应用它提供的修补程序，并查看是否有帮助。

Im trying to connect a "Information" object to many "Customers" (see code below)

When one Information object is updated, I want to send email to each Customer that is connected to the Information.

However, when I log the sold_to field that the signal recieves I always get what the data is like BEFORE the save.

I'm guessing this is because its ManyToManyField and the data is stored in a separate table, but shouldn't the post_save signal be called after all relations have been updated?

Anyone got a suggestion for a solution?

class Customer
    name = models.CharField(max_length=200)
    category = models.ManyToManyField('Category',symmetrical=False)
    contact = models.EmailField()

class Information
    name = models.CharField(max_length=200)
    email = models.EmailField(max_length=200)
    mod_date = models.DateTimeField(auto_now=True)
    sold_to = models.ManyToManyField(Customer, null=True, blank=True)


def send_admin_email(sender, instance, signal, *args, **kwargs):
    from myapp import settings
    for cust in instance.sold_to.all():
        settings.debug(cust.name)

post_save.connect(send_admin_email, sender=Information)

Edit: apollo13 in #django alerted me to this:"Related items (the things being saved into the many-to-many relation)are not saved as part of a model's save method, as you have discovered." - http://groups.google.com/group/django-users/msg/2b734c153537f970

But since its from Jul 9 2006 I really really hope there is a solution for this.

解决方案

There's an open ticket for the issue you are facing here. You could either keep an eye on that for when it makes it into a release, or you could try applying the patch that it provides and see if that helps.

这篇关于为什么Django post_save信号给我pre_save数据？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！