RichEnums

With Enums we are able to map a label to a value on the database. Use Rich Enum if you need to maintain an additional mapping at the point of enum definition, for e.g. for presentation purposes or for mapping to a different value on a different system.

e.g. rich enum definition

class User < ApplicationRecord
  # enum role: { admin: 1, user: 2 } # default enum definition
  rich_enum role: { admin: [1, 'ROLE001'], user: [2, 'ROLE101'] }, alt: 'code'
end

user = User.new(role: :admin)
user.role # => 'admin'
user.role_code # => 'ROLE001'
user.role_for_database # => 1
User.roles # => {"admin"=>1, "user"=>2}
User.role_codes # => {"admin"=>"ROLE001", "user"=>"ROLE101"}
User.role_alt_name_to_ids # => {"ROLE001"=>1, "ROLE101"=>2}

Add this line to your application's Gemfile:

gem 'rich_enums'

And then execute:

$ bundle install

Or simply run

$ bundle add rich_enums

to add to Gemfile and run bundle install in one go.

As shown in the example above, the rich_enum definition is similar to the default enum definition. It simply augments the enum definition with an additional mapping.

The additional mapping can be named with the alt option. It defaults to 'alt_name' if unspecificed. This comes in handy when you need to map to a different value on a different system.

1. Using rich_enum to define your enums provides you with an instance method (attribute name with a suffix specified with the alt property - defaults to _alt_name) to access the alternate value from the additional mapping.
2. It also provides you with a class method(attribute name with a plural suffix derived from the alt option - defaults to _alt_names) to access the additional mapping.

class User < ApplicationRecord
  # enum role: { admin: 1, user: 2 } # default enum definition
  rich_enum role: { admin: [1, 'ROLE001'], user: [2, 'ROLE101'] } # if alt is not specified, it defaults to 'alt_name'
end

user = User.new(role: :admin)
user.role # => 'admin'
user.role_alt_name # => 'ROLE001'
user.role_for_database # => 1
User.roles # => {"admin"=>1, "user"=>2}
User.role_alt_names # => {"admin"=>"ROLE001", "user"=>"ROLE101"}
User.role_alt_name_to_ids # => {"ROLE001"=>1, "ROLE101"=>2}
ExternalSystem.sync(user.external_id, role_code: user.role_alt_name)

Any arguments other than 'alt' are forwarded to the default enum definition. For e.g. in this case _prefix: true is forwarded to the default enum definition.

rich_enum payment_type: {
    upfront: [10, 'Full payment'],
    installment: [20, 'Pay in parts'],
}, _prefix: true

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

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

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

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