轨道上的红宝石 - 为什么我会得到"Unknown validator: 'MessageValidator'"？

Question

我得到这个错误

未知验证器:'MessageValidator'

我不知道为什么我得到这个。
我的代码有什么问题?

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

尝试:

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

我假设您希望在长度验证失败时消息为。您应该在该散列中包含消息，如:

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