在Rails中，如何确定一个纪录是由相关的破坏：破坏的回调？ [英] In rails, How to determine if a record was destroyed by a dependent: :destroy callback?

问题描述

我有一个记录我与 after_destroy 挂钩，需要做的是了解为何一条记录被破坏的Rails应用程序。更具体地说，如果记录被级联被破坏，因为它的家长说相关：摧毁，它需要做的事情比如果记录被单独摧毁不同

我试图做的是看它的母公司是破坏，才弄清楚，相关：？：摧毁回调完成之前父被破坏。这是有道理的，因为它应该能够失败。 （即限制）。

那么，如何做到这一点？

解决方案

要做到这一点的方法之一是使用 before_destroy 回调中的父对象，以纪念所有子对象的通过家长摧毁破坏。就像他的：

 类YourClass
  before_destroy：mark_children

  ...
  ...

  高清mark_children
    [：association1，：association2]。每做|协会| ＃阵列应该inclue协会名称恨：依赖=＆GT; ：摧毁选项
      self.send（协会）。每个做|孩子|
        母公司为已删除＃号子对象
      结束
    结束
  结束
结束
 

您还可以使用ActiveRecord的思考，以确定哪些全自动协会都​​被标记为：依赖=＆GT; ：摧毁。这样做是有帮助的，当你需要在许多类此功能。

I've got a record in my Rails app with an after_destroy hook that needs to do be aware why the record gets destroyed. More specifically, if the record is being destroyed in a cascade because its parent says dependent: :destroy, it needs to do things differently than if the record was individually destroyed.

What I tried to do is to see if its parent was destroyed?, only to figure out that dependent: :destroy callbacks are done before the parent is destroyed. Which makes sense because it should be able to fail. (i.e. restrict).

So, how do I do this?

解决方案

One way to do this is using the before_destroy callback in the parent object to mark all child objects as destroyed through parent destroy. Like his:

class YourClass
  before_destroy :mark_children

  ...
  ...

  def mark_children
    [:association1, :association2].each do |association|   # Array should inclue association names that hate :dependent => :destroy option
      self.send(association).each do |child|
        # mark child object as deleted by parent
      end
    end
  end
end

You can also use ActiveRecord Reflections to determine automaticly which associations are marked as :dependent => :destroy. Doing this is helpfull when you need this function in many classes.

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