deep_cloneableを使う

deep_cloneableで何ができる？

モデル単体ではなく、モデルに関連づいたモデルも含めてクローンしてくれます。
使い方は公式に書いてあります。

動作確認バージョン

rails (5.0.0.1)
deep_cloneable (2.2.2)

モデル定義

class Form < ApplicationRecord
  has_many :parts
end

class Part < ApplicationRecord
  belongs_to :form
  has_many :options
  has_many :validations
end

class Option < ApplicationRecord
  belongs_to :part
end

class Validation < ApplicationRecord
  belongs_to :part
end

Form -- Part  -+- Option
               |
               +- Validation

動作確認

form = Form.find(1)

dup_form = form.dup
cloned_form = form.deep_clone include: { parts: [:options, :validations] }

p dup_form
p cloned_form

p dup_form.form_parts
p cloned_form.form_parts


p cloned_form.form_parts.first.form_options
p cloned_form.form_parts.first.form_validations

cloned_form.save
p cloned_form
p cloned_form.form_parts
p cloned_form.form_parts.first.form_options
p cloned_form.form_parts.first.form_validations

output

#<Form id: nil, …, created_at: nil, updated_at: nil>
#<Form id: nil, …, created_at: nil, updated_at: nil>

#<ActiveRecord::Associations::CollectionProxy []>
#<ActiveRecord::Associations::CollectionProxy [#<Part id: nil, form_id: nil, …, created_at: nil, updated_at: nil>, #<Part id: nil, form_id: nil, …, created_at: nil, updated_at: nil>, #<Part id: nil, form_id: nil, …, created_at: nil, updated_at: nil>]>

#<ActiveRecord::Associations::CollectionProxy [#<Option id: nil, part_id: nil, …, created_at: nil, updated_at: nil>, #<Option id: nil, part_id: nil, …, created_at: nil, updated_at: nil>]>
#<ActiveRecord::Associations::CollectionProxy [#<Validation id: nil, part_id: nil, …, created_at: nil, updated_at: nil>]>

#<Form id: 5, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">
#<ActiveRecord::Associations::CollectionProxy [#<Part id: 17, form_id: 5, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">, #<Part id: 18, form_id: 5, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">, #<Part id: 19, form_id: 5, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">]>
#<ActiveRecord::Associations::CollectionProxy [#<Option id: 25, part_id: 17, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">, #<Option id: 26, part_id: 17, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">]>
#<ActiveRecord::Associations::CollectionProxy [#<Validation id: 4, part_id: 17, …, created_at: "2017-05-02 05:52:43", updated_at: "2017-05-02 05:52:43">]>