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)
endInstall 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.