ActsAsMergeable

Merge two ActiveRecord instances of the same class, with preference to the main instance on which the merge method is called on.

Installation

Add this line to your application's Gemfile:

gem 'acts_as_mergeable'

And then execute:

$ bundle

Or install it yourself as:

$ gem install acts_as_mergeable

Usage

Adding acts_as_mergeable to your ActiveRecord class gives instances of the class access to a merge method, which can be used to merge in another instance of the same class by accepting the second instance as an argument.

E.g: Given an ActiveRecord User class

class User < ActiveRecord::Base
  acts_as_mergeable
end

If active_user and inactive_user are two instances of the User class, attributes and associations of inactive_user can be merged into active_user by calling active_user.merge(inactive_user)

NOTE: Preference is always given to properties of the main/parent instance.

  > active_user = User.create(name: 'John Doe', email: 'john@doe.com')
  > inactive_user = User.create(name: '', email: 'previous.john@doe.com', alias: 'jon D doe')
  
  # merge inactive_user into active_user
  > active_user.merge(inactive_user)
  
  # active user now has attributes (and associated relationships) of the inactive user
  > active_user.name
    => 'John Doe'
  > active_user.email
    => 'john@doe.com'
  > active_user.alias
    => 'jon D doe'

An optional destroy: true can be passed to the call to merge. Setting this will ensure the destruction of the merged instance.

  > main_account = User.create(name: 'John Doe')
  > other_account = User.create(name: 'Other User')
  
  # merge other_account into main_account, specifying "destroy: true"
  > main_account.merge(other_account, {destroy: true})
  
  # Looking for the "other_account" record yields nothing as it has been deleted
  > User.find_by_id(other_account.id)
    => nil
  > User.find_by_id(main_account.id)
    => #<User id: 1, name: 'John Doe', ...>

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rspec to run the tests. You can also run rake console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/cahootify/acts_as_mergeable. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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

Code of Conduct

Everyone interacting in the ActsAsMergeable project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.