LikesControler for a Post

I have this controller that I call via Ajax, where I update the likes of a post.

I have two methods in the user model:

• already_like_post?: Where I pass the posted ID and return true or false if the post is already liked.

• dislike_post: Delete the user like for given post.

class LikesController < ApplicationController
    def create
        if !current_user.already_liked_post? params[:post_id]
            like = Like. new user: current_user, post_id: params[:post_id]
            if !like.save
                render json: like.errors
            end
        else
           current_user.dislike_post params[:post_id]
        end
        amount_of_likes = Post.find(params[:post_id]).likes.count
        render json:{status:"success",likes: amount_of_likes}
    end
end

These are the methods in the user model:

def already_liked_post?(post_id)
    self.likes.where(post_id: post_id).size == 1
end

def dislike_post(post_id)
    self.likes.find_by(post_id: post_id).destroy
end

Can you give a review of this? I don't know if this looks good or if it is the Rails way.

Some notes:

• Use 2-space indentation.

• Move all the logic to the model.

• DB deletes can also fail.

• No need for self.

• If you use object instead of object_id as argument, code is usually more declarative.

• In case of error, you are performing a double render.

I'd write:

class LikesController < ApplicationController
  def create
    post = Post.find(params[:post_id])

    if current_user.toggle_like(post)
      render(json: {status: "success", likes: post.likes.count})
    else
      render(json: {status: "error"}, status: :unprocessable_entity)
    end
  end
end

class User < ActiveRecord::Model
  # Toggle like for post. Returns boolean with the status of the operation.
  def toggle_like(post)
    likes_for_post = likes.where(post_id: post.id)

    if likes_for_post.exists?
      likes_for_post.destroy_all.all?(&:destroyed?)
    else
      likes.new(post: post).save
    end
  end
end

StackExchange Code Review Q#99021, answer score: 4