Model agnostic likes controller for SoPub

likes_controller.rb

class LikesController < ApplicationController
    
  before_filter :authenticate_user!
    
  def like
    @model = get_model(params[:model_name])
    @item = @model.find(params[:id])
    #only post to Facebook if this is their first time
    unless current_user.voted_on?(@item)
      if session[:social_mode]
          @graph = current_user.graph
            @graph.put_wall_post("", {
            :name => "#{@item.title}",
            :link => "#{item_url(@item)}",
            :caption => "{*actor*} liked #{@item.title} on SoPub"
          })
      end
    end
    if current_user.vote_exclusively_for(@item)
        respond_to do |format|
          format.html { redirect_to item_url(@item), :success => "You liked this post." }
          format.js
        end
    else
      respond_to do |format|
        format.html { redirect_to item_url(@item), :warning => "You have already liked this post." }
        format.js
      end
    end
  end

  def dislike
    @model = get_model(params[:model_name])
    @item = @model.find(params[:id])
    if current_user.vote_exclusively_against(@item)
      respond_to do |format|
        format.html { redirect_to @item }
        format.js
      end
    end
  end

  private

  def get_model(model_name)
    model_name.classify.constantize
  end

  def item_url(item)
    begin
    @url = url_for(item)
    rescue
      model = get_model(item.commentable_type)
      @parent = model.find(item.commentable_id)
      @url = url_for(@parent)
    end
    @url
  end
end