Voting of Comments

gistfile1.rb

#routes
PostitTemplate::Application.routes.draw do
  root to: 'posts#index'

  get 'register', to: 'users#new'

  get '/login', to: 'sessions#new'
  post '/login', to: 'sessions#create'
  get '/logout', to: 'sessions#destroy'

  resources :posts, except: [:destroy] do
    member do
      post :vote
    end

    resources :comments, only: [:create] do
      member do
        post :vote
      end
    end
  end

  resources :categories, only: [:index, :new, :create, :show]
  resources :users, only: [:show, :create, :edit, :update]
end

#vote model
class Vote < ActiveRecord::Base
  belongs_to :user
  belongs_to :voteable, polymorphic: true

  validates_uniqueness_of :user, scope: :voteable
end

#comment model
class Comment < ActiveRecord::Base
  belongs_to :post
  belongs_to :user, foreign_key: :user_id
  has_many :votes, as: :voteable

  validates :body, presence: true

  def total_votes
  	up_votes - down_votes
  end

  def up_votes
  	self.votes.where(vote: true).size
  end

  def down_votes
  	self.votes.where(vote: false).size
  end 
end

#comments controller
class CommentsController < ApplicationController
  before_action :require_user
  def create
    @post = Post.find(params[:post_id])
    @comment = @post.comments.build(params.require(:comment).permit(:body))
    @comment.user = current_user
    if @comment.save
      flash[:notice] = "Your comment was added."
      redirect_to post_path(@post)
    else
      render 'posts/show'
    end
  end

  def vote
    comment = Comment.find(params[:id])
    @vote = Vote.create(voteable: comment, user: current_user, vote: params[:vote])
    if @vote.valid?
      flash[:notice] = "Your vote was counted."
    else
      flash[:error] = "Didn't you already vote on this comment?"
    end
    redirect_to :back
  end
end

#voting view code from _comments.html.erb
<div class='col-md-1 well text-center'>
   <%= link_to vote_post_comment_path(comment.post, comment, vote: true), method: 'post' do %>
     <span class='glyphicon glyphicon-arrow-up'></span>
   <% end %>
   <br>
   <%= comment.total_votes %> votes
   <br>
   <%= link_to vote_post_comment_path(comment.post, comment, vote: false), method: 'post' do %>
     <span class='glyphicon glyphicon-arrow-down'></span>
   <% end %>
</div>