将 Django 项目中的信号通知限制为模型中的特定属性

Question

我添加了一条通知，每当用户向 post 提交“赞”按钮时，被赞 post 的所有者都会收到通知。

我已将每个“赞”按钮的值选项设置为 Like 或 Unlike 所以现在我试图限制通知仅在点击的“赞”的值是 [=仅 14=]。

所以，现在在 Like 模型中，我添加了信号和条件，如果 Like.value== Like 信号激活但由于某种原因它不起作用，我不确定为什么。

我的问题是：

如何设置只在Like.value==Like时发送通知信号？

这里是post models.py:

class Post(models.Model):
    title = models.CharField(max_length=100, unique=True)
    likes = models.ManyToManyField(User, related_name='liked', blank=True)

这里是赞models.py:

LIKE_CHOICES = (
    ('Like', 'Like'),
    ('Unlike', 'Unlike')
)


class Like(models.Model):
    # To know Who liked
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    post = models.ForeignKey(Post, on_delete=models.CASCADE)
    value = models.CharField(choices=LIKE_CHOICES, default='Like', max_length=8)
    updated = models.DateTimeField(auto_now=True)
    created = models.DateTimeField(auto_now=True)

    def __str__(self):
        return f"{self.post}-{self.user}-{self.value}"

    def user_liked_post(sender, instance, *args, **kwargs):
        if Like.value=='Like':
            like = instance
            post = like.post
            sender = like.user
            notify = Notification(post=post, sender=sender, user=post.author, notification_type=1)
            notify.save()
        else:
            None

    def user_unlike_post(sender, instance, *args, **kwargs):
        like = instance
        post = like.post
        sender = like.user
        notify = Notification.objects.filter(post=post, sender=sender, user=post.author, notification_type=1)
        notify.delete()


# Likes
post_save.connect(Like.user_liked_post, sender=Like)
post_delete.connect(Like.user_unlike_post, sender=Like)

这是通知models.py

class Notification(models.Model):
    NOTIFICATION_TYPES=((1,'Like'),(2,'Comment'),(3,'Follow'))

    post = models.ForeignKey('blog.Post', on_delete=models.CASCADE, related_name="noti_post", blank=True, null=True)
    sender = models.ForeignKey(User, on_delete=models.CASCADE, related_name="noti_from_user")
    user = models.ForeignKey(User, on_delete=models.CASCADE,related_name="noti_to_user")
    notification_type= models.IntegerField(choices=NOTIFICATION_TYPES)

这里是views.py:

def ShowNotifications(request):
    user=request.user
    notifications= Notification.objects.filter(user=user).order_by('-date')
    template= loader.get_template('notifications/notifications.html')

    context= {
        'notifications':notifications
    }
    return HttpResponse(template.render(context, request))

Answer 1

在 post_save 处理程序中，您比较如下 if Like.value=='Like':

但是 Like 是一个 class，其中 value 是一个字段，因此比较永远不会是 True.

    def user_liked_post(sender, instance, *args, **kwargs):
        like = instance
        if like.value=='Like':
            post = like.post
            sender = like.user
            notify = Notification(
                post=post, sender=sender, user=post.author, notification_type=1
            )
            notify.save()

我注意到的另一件事，我不确定影响是什么。 def user_liked_post 是模型上的一种方法。因此它期望的第一个参数是 self。但是 post 保存处理程序将其用作 class 方法。但正因为如此 sender 可能会是 cls，因此 Like.

将 Django 项目中的信号通知限制为模型中的特定属性

Restricting Signal Notifications in a Django Project to specific Attribute in Model

python

django

django-signals