faq/app/models/qa_file.rb

class QaFile

  include Mongoid::Document
  include Mongoid::Timestamps

  mount_uploader :file, AssetUploader

  field :description, localize: true
  field :should_destroy, :type => Boolean  
  field :title, localize: true
  field :choose_lang, :type => Array, :default => ["en","zh_tw"]
  belongs_to :qa
  def file_title
    if self.description.present?
      return self.description
    elsif self.title.present?
      return self.title
    else
      return (File.basename(self.file.path) rescue nil)
    end
  end
  def enabled_for?(lang)
    if lang.nil?
      return true
    else
      return self.choose_lang.include?(lang)
    end
  end
end