StateMachineEnum

This concern adds a method called "state_machine_enum" useful for defining an enum using string values along with valid state transitions. Validations will be added for the state transitions and a proper enum is going to be defined. For example:

state_machine_enum :state do |states|
  states.permit_transition(:created, :approved_pending_settlement)
  states.permit_transition(:approved_pending_settlement, :rejected)
  states.permit_transition(:created, :rejected)
  states.permit_transition(:approved_pending_settlement, :settled)
end

Install the gem and add to the application's Gemfile by executing:

$ bundle add state_machine_enum

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install state_machine_enum

StateMachineEnum needs to be extended and then it could be used, as example in AR model.

class User < ApplicationRecord
  include StateMachineEnum

  state_machine_enum :state do |s|
    s.permit_transition(:registered, :active)
    s.permit_transition(:active, :banned)
    s.permit_transition(:banned, :active)
    s.permit_transition(:active, :deleted)
  end
end

And then it will offer bunch of convenient methods and callbacks that ensure proper state transitions.

user = User.new(state: 'registered')
user.active?
user.registered! # throws InvalidState error, because state can not transition to "registered".

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. 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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/cheddar-me/state_machine_enum.

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