callback - before_destroy 回调不会阻止记录被删除

Question

如果有 child ，我正在努力防止记录被破坏。

class Submission < ActiveRecord::Base

has_many :quotations, :dependent => :destroy

 before_destroy :check_for_payments


  def quoted?
    quotations.any?
  end


  def has_payments?
   true if quotations.detect {|q| q.payment}
  end


  private

  def check_for_payments
    if quoted? && has_payments?
      errors[:base] << "cannot delete submission that has already been paid"
      false
    end
  end

end

class Quotation < ActiveRecord::Base

    #associations
    belongs_to :submission
        has_one :payment_notification   
        has_one :payment

         before_destroy :check_for_payments

private 

def check_for_payments
  if payment_notification || payment
    errors[:base] << "cannot delete quotation while payment exist"
    return false
  end
end
end

当我测试此代码时，before_destroy :check_for_ payments 会阻止删除报价记录。

但是，提交 before_destroy 回调中的 :check_for_ payment 并不能阻止提交被删除。

如何阻止付款后的提交内容被销毁？

Answer 1

在Rails 5中，您必须抛出:abort，否则它将无法工作。 (甚至返回false)

此外，您应该将 prepend: true 添加到回调中，以确保它在父模型上的 dependent: :destroy 之前运行。

这样的事情应该有效:

class Something < ApplicationRecord

  before_destroy :can_destroy?, prepend: true

  private

  def can_destroy?
    if model.something?
      self.errors.add(:base, "Can't be destroy because of something")
      throw :abort
    end
  end
end