StateMachines Active Record Integration

The Active Record 4.1+ integration adds support for database transactions, automatically saving the record, named scopes, validation errors.

Dependencies

Active Record 4.1+

Installation

Add this line to your application's Gemfile:

gem 'state_machines-activerecord'

And then execute:

$ bundle

Or install it yourself as:

$ gem install state_machines-activerecord

Usage

class Vehicle < ActiveRecord::Base
  state_machine :initial => :parked do
    before_transition :parked => any - :parked, :do => :put_on_seatbelt
    after_transition any => :parked do |vehicle, transition|
      vehicle.seatbelt = 'off'
    end
    around_transition :benchmark

    event :ignite do
      transition :parked => :idling
    end

    state :first_gear, :second_gear do
      validates_presence_of :seatbelt_on
    end
  end

  def put_on_seatbelt
    ...
  end

  def benchmark
    ...
    yield
    ...
  end
end

Scopes

Usage of the generated scopes (assuming default column state):

Vehicle.with_state(:parked)                         # also plural #with_states
Vehicle.without_states(:first_gear, :second_gear)   # also singular #without_state

Contributing