announcement-test/app/models/bulletin_file.rb

# encoding: utf-8
class BulletinFile

  include Mongoid::Document
  include Mongoid::Timestamps

  mount_uploader :file, AssetUploader

  field :description, localize: true
  field :title, localize: true
  field :choose_lang, :type => Array, :default => ["en","zh_tw"]
  field :privacy_type, type: String, default: 'public'
  belongs_to :bulletin
  def self.to_fronted(locale=I18n.locale)
    self.all.map{|file| file.to_fronted(locale)}.compact rescue []
  end
  def to_fronted(locale=I18n.locale)
    file = self
    (file.enabled_for?(locale) && !file[:file].blank?) ? { "file_url" =>  "/xhr/announcements/file/#{file.id}/#{file['file']}" + "\" title=\"#{file.file_title}",
      "file_title" => (file.title.blank? ? URI.unescape(File.basename(file.file.path)) : file.title rescue '') 
    } : nil rescue nil
  end

  def file_title
    if self.description.present?
      return self.description
    elsif self.title.present?
      return self.title
    else
      return File.basename(self.file.path)
    end
  end
  def enabled_for?(lang)
  	if lang.nil?
  		return true
  	else
  		return self.choose_lang.include?(lang)
  	end
  end
  def can_access?(user)
    if user.nil? && self.privacy_type == 'logged_in'
      return false
    else
      return true
    end
  end
end