ActiveRecord的：我怎样才能克隆嵌套的关联？ [英] ActiveRecord: How can I clone nested associations?

问题描述

我目前克隆单层关联是这样的：

I'm currently cloning a single-level association like this:

class Survey < ActiveRecord::Base
  def duplicate
    new_template = self.clone
    new_template.questions << self.questions.collect { |question| question.clone } 
    new_template.save   
  end
end

让克隆调查然后克隆了问题与这项调查有关。精细。这工作得很好。

So that clones the Survey then clones the Questions associated with that survey. Fine. That works quite well.

但我有麻烦的是，每道题的has_many 答案。因此，调查的has_many问题其中的has_many答案。

But what I'm having trouble with is that each question has_many Answers. So Survey has_many Questions which has_many Answers.

我无法弄清楚如何正确克隆的答案。我试过这样的：

I can't figure out how to clone the answers properly. I've tried this:

def duplicate
  new_template = self.clone

  self.questions.each do |question|
    new_question = question.clone
    new_question.save

    question.answers.each do |answer|
      new_answer = answer.clone
      new_answer.save
      new_question.answers << answer
    end

    new_template.questions << question
  end

  new_template.save   
end

但是，这确实有些奇怪的东西与实际取代了原来的答案，然后创建新的，所以ID的停止正确匹配。

But that does some weird stuff with actually replacing the original answers then creating new ones, so ID's stop matching correctly.

推荐答案

使用 deep_clonable宝石

new_survey = original_survey.clone :include => [:questions => :answers]

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