Question

这是我的代码：

class Invitation(models.Model):   
    #other fields here
    Code = models.CharField(max_length=128, null=True, blank=True)
    Tags = models.ManyToManyField("CategorieInvitation", null=True, blank=True)
    Tags = models.ManyToManyField("Usage", null=True, blank=True)
    Note = models.CharField(max_length=128, null=True, blank=True)
    Used = models.BooleanField(default=False, blank=True)
    SendTo = models.EmailField(null=True, blank=True)
    # a revoir
    def post_save(self, model_instance, add):
        if self.Code.__len__() == 0 :
            self.Code = generate_invitation(1)[0]
            self.save()

如果代码为空或如果在django-admin界面中创建，则如何将代码替换为generate_invitation的结果？

问候比西耶尔

Answer 1

对于您要做的事情，覆盖save方法可能更容易，也更有效。

class Invitation(models.Model):   
    #other fields here
    code = models.CharField(max_length=128, null=True, blank=True)
    tags = models.ManyToManyField("CategorieInvitation", null=True, blank=True)
    tags2 = models.ManyToManyField("Usage", null=True, blank=True)
    note = models.CharField(max_length=128, null=True, blank=True)
    used = models.BooleanField(default=False, blank=True)
    send_to = models.EmailField(null=True, blank=True)
    # a revoir

    def save(self, *args, **kwargs):
        if not self.code:
            self.code = generate_invitation(1)[0]

        super(Invitation, self).save(*args, **kwargs)

顺便说一句post_save不应该是模型实例方法。请参阅：https://docs.djangoproject.com/en/1.4/ref/signals/#signals

如果django模型中的字段为空或空白，则保存操作？

1 个答案: