Delegate ActiveRecord model attributes and associations.
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Stores and retrieves delegatable data through attributes on a ActiveRecord class, with support for translatable attributes.

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Add this line to your application's Gemfile:

gem 'active_delegate'

And then execute:

$ bundle

Or install it yourself as:

$ gem install active_delegate


class Address < ActiveRecord::Base
  # columns: :city, :district

class Person < ActiveRecord::Base
  # columns: :name, email, :phone, :address_id

  include ActiveDelegate

  belongs_to :address
  has_one    :user
  has_many   :books

  delegate_attributes to: :address, prefix: true, localized: true

params = {
  name:                'John',
  email:               '',
  address_city:        'Athens',
  address_city_el:     'Αθήνα',
  address_district:    'Attiki',
  address_district_el: 'Αττική'

person =                # 'John'
person.address_city        # 'Athens'        # 'Athens'
person.address_city_el     # 'Αθήνα'
person.address.city_el     # 'Αθήνα'
person.address_district    # 'Attiki'
person.address.district    # 'Attiki'
person.address_district_el # 'Αττική'
person.address.district_el # 'Αττική'

class User < ActiveRecord::Base
  # columns: :login, :password, :person_id

  include ActiveDelegate

  belongs_to :person, autosave: true

  delegate_associations to: :person
  delegate_attributes   to: :person

params = {
  login:    'jonian',
  password: 'passwd',
  name:     'John',
  email:    ''

user =           # 'John'
user.login          # 'jonian'
user.user           # @user
user.books          # []          # ''         # true
user.email_changed? # true
user.email_was      # nil


After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment. To install this gem onto your local machine, run bundle exec rake install.


Bug reports and pull requests are welcome on GitHub at


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