爲什麼我會得到「未知驗證器：'MessageValidator'」？

Question

我得到這個錯誤

未知的驗證： 'MessageValidator'

我不知道爲什麼我收到。
我的代碼有什麼問題？

validates :title, 
    :presence => true, 
    :uniqueness => true, 
    :length => { :maximum => 100 }, 
    :message => "Must be input and has to be less than 100 characters, and unique." 

Answer 1

嘗試：

validates :title, 
      :presence => {:message => "Title can't be blank." }, 
      :uniqueness => {:message => "Title already exists."}, 
      :length => { :maximum => 100, :message => "Must be less than 100 characters"} 

Answer 2

我假設你想要的消息是當長度驗證失敗。你應該包括消息散列，如：

validates :title, 
    :presence => true, 
    :uniqueness => true, 
    :length => { :maximum => 100, :message => "Must be less than 100 characters"}