Django Favorite view

Question

I’m trying to create a favorite button for an app’s posts, but I can’t figure out how to create one because it contains an entire number. When the user clicks on the favorite button. The button will increase to 1 and will be displayed near the image.

This is my Post model.

class Post(models.Model):
    title = models.CharField(max_length=100)
    slug = AutoSlugField(unique=True, always_update=False, populate_from="title")
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    body = models.TextField(max_length=1050)
    created = models.DateTimeField(auto_now_add=True)
    updated = models.DateTimeField(auto_now=True)
    image = models.ImageField(null=True, blank=True, upload_to=upload_perfil_user)   
    category = models.ForeignKey(
        Category, related_name="posts", on_delete=models.CASCADE, null=True
    )
    class Meta:
        ordering = ("-created",)

    def __str__(self):
        return self.title

    def get_absolute_url(self):
        return reverse("blog:detail", kwargs={"slug": self.slug})

    def comment_number(self):
        return len(self.comment_set.all())

E esse é o modelo do Favorite : 

 

class Favorite(models.Model):
    author = models.ForeignKey(User, on_delete=models.CASCADE)
    post = models.ForeignKey(Post, on_delete=models.CASCADE)    
    created = models.DateTimeField(auto_now_add=True)    

But I’m having extreme difficulty creating the system view :

class Favorite(CreateView):
    model = Favorite
 
    def form_valid(self):    
            form.instance.author=request.user #id do usuario
    #id do post
    #se o usuario ja favoritou, então não faça nada
    #se o usuario não favoriou então suba a info pro banco (id_user, id_post)
    #retorne o mesmo url talvez... Não tive ideia pro retorno da função

Can anyone help me create the view from the favorite button ? I have the table in the bank due to the model, but wanted to understand the logic of how to create the view in a way that the two foreing Keys (User and Post) are populated, with the exception of Foreign key user is one Too Many Post