ruby on rails - Accessing a model from another model -

after post.all, i'm trying return json array of post objects custom attribute. here have:

@posts = post.includes(:profil).page(params[:page]).order('created_at desc') render json: @posts.to_json(:include => :profil,                             :methods => [:image_url, :vote_modificator]) 

this method correctly returns list of posts, including profil , custom attribute image_url. have model vote, belongs profil , post:

class vote < activerecord::base   attr_accessible :value   belongs_to :profil   belongs_to :post end 

i want insert in each post vote value corresponding , current_user defined in application_controller.rb:

  def current_user       @current_user ||= user.find_by_auth_token!(cookies[:auth_token]) if cookies[:auth_token]    end    helper_method :current_user 

i tried add method in to_json, method defined in model can't access helper. solution solve problem?