python - 在 Django 中使用 Pre_delete 信号

Question

在我的应用程序中，我想跟踪所有被删除的问题。所以我在我的模型文件中创建了一个类(表)。

class Deleted(models.Model):
question = models.IntegerField(null=True, blank=True)#id of question being deleted
user = models.IntegerField(null=True, blank=True)#id of user deleting the question
dt = models.DateTimeField(null=True, blank=True)#time question is deleted

当用户尝试删除问题时调用此删除函数:

def delete_questions(request, user, questions):
  for q in questions:
        q.delete()

我的疑问是如何发出 django 的 pre_delete 信号来填充我创建的新表。

~新手尝试繁重的任务~提前致谢:)

Answer 1

您首先定义 receiver你想使用:

def log_deleted_question(sender, instance, using, **kwargs):
    d = Deleted()
    d.question = instance.id
    d.dt = datetime.datetime.now() # consider using auto_now=True in your Deleted definition
    # not sure how you'd get the user via a signal, 
    # since it can happen from a number of places (like the command line)
    d.save()

然后定义你的接收装饰器:

from django.db.models.signals import pre_delete
from django.dispatch import receiver

@receiver(pre_delete, sender=Question, dispatch_uid='question_delete_log')

全部添加:

from django.db.models.signals import pre_delete
from django.dispatch import receiver

@receiver(pre_delete, sender=Question, dispatch_uid='question_delete_signal')
def log_deleted_question(sender, instance, using, **kwargs):
    d = Deleted()
    d.question = instance.id
    d.dt = datetime.datetime.now() 
    d.save()

您可以将此函数放在您的 models.py 文件中，因为您知道它会被正确加载和连接。

但问题是您没有收到请求删除的用户。由于删除可以从 django api(命令行、shell 等)触发，它没有与之关联的请求。出于这个原因，如果将用户与删除一起存储是绝对重要的，那么您可能希望避免使用信号。