Gem Version Build Status Test Coverage Docs


A flexible gem for cloning your models. Clowne focuses on ease of use and provides the ability to connect various ORM adapters.

📖 Read Evil Martians Chronicles to learn about possible use cases.

📑 Documentation

Sponsored by Evil Martians


To install Clowne with RubyGems:

gem install clowne

Or add this line to your application's Gemfile:

gem 'clowne'

Quick Start

Assume that you have the following model:

class User < ActiveRecord::Base  # create_table :users do |t|
  #  t.string :login
  #  t.string :email
  #  t.timestamps null: false
  # end

  has_one :profile
  has_many :posts

class Profile < ActiveRecord::Base  # create_table :profiles do |t|
  #   t.string :name
  # end


class Post < ActiveRecord::Base  # create_table :posts


Let's declare our cloners first:

class UserCloner < Clowne::Cloner
  adapter :active_record

  include_association :profile, clone_with: SpecialProfileCloner
  include_association :posts

  nullify :login

  # params here is an arbitrary Hash passed into cloner
  finalize do |_source, record, params| = params[:email]

class SpecialProfileCloner < Clowne::Cloner
  adapter :active_record

  nullify :name

Now you can use UserCloner to clone existing records:

user = User.last# => <#User id: 1, login: 'clown', email: '[email protected]'>

operation =, email: '[email protected]')# => <#Clowne::Utils::Operation...>

operation.to_record# => <#User id: nil, login: nil, email: '[email protected]'>

operation.persist!# => true

cloned = operation.to_record# => <#User id: 2, login: nil, email: '[email protected]'>

cloned.# => nil => "[email protected]"

# associations:
cloned.posts.count == user.posts.count# => true => nil

Take a look at our documentation for more info!

Supported ORM adapters

Adapter 1:1 *:1 1:M M:M
Active Record has_one belongs_to has_many has_and_belongs_to
Sequel one_to_one - one_to_many many_to_many



The gem is available as open source under the terms of the MIT License.