Question

我有一个post_save，它在创建Subscription对象后创建一个Product对象。我有实例名称填充几个字段，我还想传入一个额外的属性。这是我的post_save：

@receiver(post_save, sender=Subscription)
def create_product_subscription(sender, **kwargs):
    subscription = Category.objects.get(name="Subscription")
    if kwargs.get('created', False):
        Product.objects.get_or_create(name=kwargs.get('instance'), 
        slug=slugify(kwargs.get('instance')), 
        price=44.98, 
        quantity='3000', 
        publish_date=kwargs.get('instance'), //this is where I'd like to pass an attribute of the instance
        categories=subscription)

这是我的订阅模型：

class Subscription(models.Model):
  name = models.CharField(max_length=200)
  start_date = models.DateField()
  end_date = models.DateField()
  date = models.DateTimeField(auto_now_add=True, blank=True)
  def __unicode__(self):
      return unicode(self.start_date)

我希望Catalog Publish_Date从Subscription start_date字段中提取它的值。

Answer 1

kwargs.get('instance')会为您提供发件人对象的实例。

一旦我们拥有了实例对象，我们就可以在实例上执行点符号查找来获取属性。

kwargs.get('instance').yourattribute

或者，我们可以使用更具说明性的函数定义，并将实例和创建的变量作为位置参数包含在Django文档中，https://docs.djangoproject.com/en/dev/ref/signals/#django.db.models.signals.post_save

以下是使用位置参数的代码，例如

@receiver(post_save, sender=Subscription)
def create_product_subscription(sender, instance, created, **kwargs):
    subscription = Category.objects.get(name="Subscription")
    if created:
        Product.objects.get_or_create(name=instance, 
        slug=slugify(instance), 
        price=44.98, 
        quantity='3000', 
        publish_date=instance.start_date, //this is where I'd like to pass an attribute of the instance
        categories=subscription)

Django post_save获取实例的属性

1 个答案: