如何使用djago信号从django中的manytomanyfield获取用户,并使用received many to many用户字段创建另一个对象

我想知道有没有什么方法可以让我们使用信号在一个模型中获得更新的多对多字段并将它们发布到另一个模型

class Post(models.Model):

    name=models.CharField(max_length=24)
    nc=models.ManyToManyField(settings.AUTH_USER_MODEL)
    def __str__(self):
        return self.name
        # return self.name
m2m_changed.connect(receiver=like_post,sender=Post.nc.through)

我想在post model的nc字段中收集更新的记录,并使用信号创建一个使用函数的对象这是连接到POST模型的信号

def like_post(sender, *args, **kwargs):
    # if kwargs['action'] in ('post_update'):
    if kwargs['action'] in ('post_add', 'post_remove','post_update'):

        print(kwargs['instance'])
        instance = kwargs['instance']
        print(instance)
        notify = Notify.objects.create(
                 recipient=instance,
                 creator=Post.objects.get(pk=50),
                  state='unread',
                   type=kwargs['action'],
                )
    else:
        print('no instance')

在收件人和创建者部分,我想用一个现有的用户对象更新这些字段创建者是更新manytomanyfield的人,收件人是创建该帖子的人

notify model:
class Notify(models.Model):
    recipient = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='notify_recipient',on_delete=models.CASCADE)
    creator = models.ForeignKey(settings.AUTH_USER_MODEL, related_name='notify_sender',on_delete=models.CASCADE)
    state = ('read', 'unread', 'unseen')
    type = models.CharField(max_length=30, blank=True)
    url = models.CharField(max_length=50, blank=True)

每当我运行这个实例时,它只打印post对象名并引发这个错误

ValueError at /admin/posts/post/50/change/
Cannot assign "<Post: ok>": "Notify.recipient" must be a "User" instance.

notify = Notify.objects.create( recipient=instance, creator=Post.objects.get(pk=50), state='unread', type=kwargs['action'], )

notify = Notify.objects.create( recipient=instance.nc, # find out how to pass the user of the post here creator=Post.objects.get(pk=50), # replace by an user instance here instead of a post instance state='unread', type=kwargs['action'], )

class PostAdmin(admin.ModelAdmin): def save_related(self, request, form, formsets, change): if not form.cleaned_data['nc']: form.cleaned_data['nc'] = [request.user] form.save_m2m()