ruby-on-rails - 在Ruby类中干燥条件验证

我怎样才能干掉我的验证码？我有一个Discussion模型，它有一个category和status字段。状态值取决于类别值。例如，category == 'question'只能在STATUSES[:question]中有状态的讨论。

  STATUSES   = {
    question:   %w[answered],
    suggestion: %w[pending planned started completed declined],
    problem:    %w[started solved]
  }
  validates :status, allow_blank: true, inclusion: { in: STATUSES[:question] },   if: lambda { self.category == 'question' }
  validates :status, allow_blank: true, inclusion: { in: STATUSES[:suggestion] }, if: lambda { self.category == 'suggestion' }
  validates :status, allow_blank: true, inclusion: { in: STATUSES[:problem] },    if: lambda { self.category == 'problem' }

我在用Rails 3。

最佳答案

:inclusion :in接受lambda本身：

validates :status, inclusion: { in: lambda { |o| STATUSES[o.category.to_sym] } }

文档：http://apidock.com/rails/ActiveModel/Validations/HelperMethods/validates_inclusion_of