检查所有关联之前，摧毁轨道 [英] Check all associations before destroy in rails

问题描述

我在我的应用程序的重要模式，有许多关联。如果我想签入before_destroy回调的所有引用，我不得不做这样的事情：

I have an important model in my application, with many associations. If I want to check all the references in a before_destroy callback, i'd have to do something like:

has_many :models_1
has_many :models_2
mas_many :models_3
....
....
has_many :models_n

before_destroy :ensure_not_referenced

def :ensure_not_referenced
   if models_1.empty? and models_2.empty? and models_3.empty? and ... and models_n.empty?
       return true
   else
       return false
       errors.add(:base,'Error message')
   end
end

现在的问题是，有一次在执行所有验证的方法吗？
感谢名单！

The question is, is there a way to perform all the validations at once? Thanx!

推荐答案

您可以通过：依赖=＆GT; ：限制选项，你的的has_many 调用：

You can pass the :dependent => :restrict option to your has_many calls:

has_many :models, :dependent => :restrict

这样的话，你将只能销毁对象，如果没有其他相关的对象引用它。

This way, you will only be able to destroy the object if no other associated objects reference it.

其他选项是：

• ：摧毁 - 摧毁每一个相关联的对象调用它们的摧毁法


• ：DELETE_ALL - 删除每个关联对象的没有调用它们的摧毁方法。


• ：废止 - 关联对象的外键设置为 NULL < STRONG>无调用它们保存回调。

• :destroy - destroys every associated object calling their destroy method.
• :delete_all - deletes every associated object without calling their destroy method.
• :nullify - sets the foreign keys of the associated objects to NULL without calling their save callbacks.

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