ruby-on-rails - 如何根据其他属性值添加自定义验证消息？

Question

我正在使用 Ruby on Rails 3.2.9，我只是想使用 state_machine gem 。我有以下声明:

# Model class attributes are:
#
# [String]  status
# [Boolean] checkin_1
# [Boolean] checkin_2
#
class Article < ActiveRecord::Base
  state_machine :attribute => :status, :initial => :unconfirmed do
    state :confirmed, :value => 'confirmed'
    state :unconfirmed, :value => 'unconfirmed'

    event :confirm do
      transition :unconfirmed => :confirmed
    end

    event :unconfirm do
      transition :confirmed => :unconfirmed
    end
  end
end

我想在触发 confirm 事件和 checkin_1 和/或 checkin_2 时向实例对象添加自定义验证消息(避免保存这些对象) 值为 false。也就是说，假设我正在尝试确认以下每个对象:

<#Article id: 1, :status: 'unconfirmed', checkin_1: false, checkin_2: false>
<#Article id: 1, :status: 'unconfirmed', checkin_1: false, checkin_2: true>
<#Article id: 1, :status: 'unconfirmed', checkin_1: true, checkin_2: false>

然后我想避免保存对象并分别添加错误消息，如下所示:

"can not be confirmed if it is not checked for 1 and 2"
"can not be confirmed if it is not checked for 1"
"can not be confirmed if it is not checked for 2"

我应该怎么做？

Answer 1

这样做怎么样:

state confirmed do
  validate do
    if !checkin_1 and !checkin_2
       msg = "can not be confirmed if it is not checked for 1 and 2"
       errors.add(:checkin_1, msg)
       errors.add(:checkin_2, msg)
    elsif !checkin_1
       errors.add(:checkin_1, "can not be confirmed if it is not checked for 1")
    elsif !checkin_2
       errors.add(:checkin_2, "can not be confirmed if it is not checked for 2")
    end
  end
end