module CacheableFlash
  def self.included(base)
    base.after_filter :write_flash_to_cookie
  end
 
  def write_flash_to_cookie
    cookie_flash = cookies['flash'] ? JSON.parse(cookies['flash']) : {}
 
    flash.each do |key, value|
      if cookie_flash[key.to_s].blank?
        cookie_flash[key.to_s] = value
      else
        cookie_flash[key.to_s] << "<br/>#{value}"
      end
    end
 
    cookies['flash'] = cookie_flash.to_json
    flash.clear
  end
end