如何基于通过Django生成的新主键发送电子邮件？

Question

我想在Django中生成新的主键时向用户发送电子邮件。 我在Models.py中的代码：

class PurchaseOrder(models.Model):
    product = models.CharField(max_length=256)
    vendor = models.CharField(max_length=256)
    dollar_amount = models.FloatField()
    item_number = models.AutoField(primary_key=True)

我已将其编码为每次刷新页面时都可以发送电子邮件的位置

email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
email.send()

但是我该如何做，以便每次生成新的主键时都发送电子邮件？

Answer 1

使用django信号 。

from django.db.models import signals

def send_email_on_new_order(instance, created, raw, **kwargs):
    # Fixtures or updates are not interesting.
    if not created or raw:
        return

    # `instance` is your PurchaseOrder instance.
    email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
    email.send()

signals.post_save.connect(send_email_on_new_order, sender=PurchaseOrder, dispatch_uid='send_email_on_new_order')

您必须将此代码粘贴到将在加载django期间执行的代码处，例如models.py

示例models.py ：

from django.core.mail import EmailMessage
from django.db import models
from django.db.models import signals

class PurchaseOrder(models.Model):
    product = models.CharField(max_length=256)
    vendor = models.CharField(max_length=256)
    dollar_amount = models.FloatField()
    item_number = models.AutoField(primary_key=True)

def send_email_on_new_order(instance, created, raw, **kwargs):
    # Fixtures or updates are not interesting.
    if not created or raw:
        return

    # `instance` is your PurchaseOrder instance.
    email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
    email.send()

signals.post_save.connect(send_email_on_new_order, sender=PurchaseOrder, dispatch_uid='send_email_on_new_order')

Answer 2

收听post_save信号。

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

@receiver(signals.post_save, sender=PurchaseOrder)
def email_handler(sender, **kwargs):
    if kwargs['created']:
        email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
        email.send()

或在模型中定义自定义save方法。

class PurchaseOrder(models.Model):
    def save(self, *args, **kwargs):
        # Check if this is a new key
        if not self.pk:
            email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
            email.send()
        super(PurchaseOrder, self).save(*args, **kwargs)

Answer 3

@voithos是正确的，因为此自定义保存是解决此问题的好方法。 然而，根据问题的严格应答，电子邮件被发送技术上的主键是创建之前 。 可能没关系，尽管如果这样做，我将订购如下代码：

def save(self, *args, **kwargs):
    email = False  # Don't email by default
    # Check if this is a new key
    if not self.pk:
        email = EmailMessage('Purchase Order System', 'your message here', to=['youremail@gmail.com'])
    super(PurchaseOrder, self).save(*args, **kwargs)
    if email:  # Email was created, and we have a new Primary Key, so send now.
        email.send()

注意：如果您需要引用新创建实例的方法（例如，电子邮件需要包含包含刚刚创建的主键的链接），我个人会使用@kroolik提供的信号方法。