orbit-basic/app/models/user.rb

class User
  include MongoMapper::Document
 
  devise :authenticatable, :recoverable, :rememberable, :trackable
  
  key :use_attributes, Array
  
  def method_missing(method)
    safe_read(method)
  end
  
  def safe_read(key)
    self[key]
    rescue MongoMapper::KeyNotFound
      return ""
  end
  
end