gistfile1.rb

#coding: UTF-8
class CommentsController < ApplicationController

  before_filter :fetch_comment, except: [:create, :new]
  before_filter :authenticate_user!, only: :vote
  before_filter :prevent_owner_vote, only: :vote
  before_filter :get_parent, except: [:vote, :plusminus]

  def new
    @parent.comments.build
    render layout: false
  end

  def create
    @comment = @parent.comments.new(params[:comment])
    @article = @comment.article_parent
    @comment.user = current_user
    @comment.article_id = @article.id
    if @comment.save
      respond_to do |format|
        format.html { redirect_to article_path(@article), notice: 'Спасибо за комментарий' }
        format.js
      end
    end
  end

  def destroy
    @comment.destroy
    redirect_to :back, notice: 'Comment removed'
  end

  def vote
    begin
      vote_for_or_against
      render text: 'Спасибо за ваш голос', status: 200
    rescue
      render text: 'Вы уже голосовали за этот комментарий', status: 404
    end
  end

  def plusminus
    @plusminus = @comment.plusminus
    render layout: false
  end

  private

  def get_parent
    @parent = Article.find(params[:article_id]) if params[:article_id]
    @parent = Comment.find_by_id(params[:comment_id]) if params[:comment_id]
    redirect_to root_path, notice: 'Неправильные параметры комментария' unless defined?(@parent)
  end

  def fetch_comment
    @comment = Comment.find(params[:id])
  end

  def prevent_owner_vote
    if @comment.user == current_user
      render text: 'Вы не можете голосовать за собственный комментарий', status: 404
    end
  end

  def vote_for_or_against
    if params[:vote] == 'up'
      current_user.vote_for(@comment)
    else
      current_user.vote_against(@comment)
    end
  end
end