ruby-on-rails - ActiveRecord:如何克隆嵌套关联？

Question

我目前正在克隆这样的单级关联:

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

这样就克隆了 Survey然后克隆 Questions与该调查相关。美好的。这很好用。

但我遇到的问题是每个问题 has_many Answers .所以 Survey has_many Questions which has_many Answers .

我不知道如何正确克隆答案。我试过这个:

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

但这确实做了一些奇怪的事情，实际上替换了原始答案然后创建了新答案，因此 ID 停止正确匹配。

Answer 1

使用 deep_clonable gem

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