如何获取与作者相关的点赞总数，并在达到一定数量时使用它发送通知

Question

I have a notification system in my Django project, when a user likes a Post the author of the post receives a notification that a post is liked and when this like is unliked the notification is deleted.

Now I am trying to add a functionality in the notification system to get the total number of likes for all the posts created by an author and send a notification to the author when the total of likes reaches a certain number, instead I set a function that when a post reaches a certain number of likes a notification is sent.

I have been trying to accomplish this but I am getting several errors. I am going to comment on my trials so in the below codes.

As per the last trial I have made I am receiving: TypeError: total_likes_received() takes 1 positional argument but 2 were given

Here is the Post model

class Post(models.Model):
    author = models.ForeignKey(
        User, on_delete=models.CASCADE, related_name='author')
    num_likes = models.IntegerField(default=0, verbose_name='No. of Likes')
    likes = models.ManyToManyField(User, related_name='liked', blank=True)

Here is the Like model

class Like(models.Model):
    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)

    def total_likes_received(self):
        return self.filter(post__author=Post.author).count()

#The number of Likes received from a post
    def like_progress(sender, instance, *args, **kwargs):
        like = instance
        post = like.post
        sender = like.user

        if post.num_likes == 2:
            notify = Notification(post=post, sender=sender,
                                  user=post.author, notification_type=3)
            notify.save()

post_save.connect(Like.like_progress, sender=Like)
-------------------------My Trial---------------------------
    # def total_likes_received(user):
    #     return Like.objects.filter(post__author=Post.author).count()
#(This Trial returned TypeError: Field 'id' expected a number but got <django.db.models.fields.related_descriptors.ForwardManyToOneDescriptor object at 0x03F05DA8>.)

    def total_likes_received(user):
        return Like.filter(post__author=Post.author).count()

        # The number of Likes received from all posts
    def total_likes_progress(instance, *args, **kwargs):
        like = instance
        post = like.post
        user = post.author

        if like.total_likes_received(user) == 10:
            notify = Notification(user=post.author, notification_type=3)
            notify.save()
post_save.connect(Like.total_likes_progress, sender=Like)
-------------------------My Trial---------------------------

Here is the Notification model

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

    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)

Answer 1

Do the following in your Like model to solve the problem.

class Like(models.Model):
    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)
    
    def total_likes_received(self, user):
        return Like.objects.filter(post__author=user).count()

    def total_likes_progress(instance, *args, **kwargs):
        like = instance
        post = like.post
        sender = like.user

        if like.total_likes_received(user) == 10:
            notify = Notification(sender=sender, user=post.author, notification_type=3)
            notify.save()

post_save.connect(Like.total_likes_progress, sender=Like)

Here taking user as an argument of total_likes_received and filtering with it.