• Stars
    star
    402
  • Rank 107,380 (Top 3 %)
  • Language
    Ruby
  • License
    MIT License
  • Created almost 10 years ago
  • Updated 8 months ago

Reviews

There are no reviews yet. Be the first to send feedback to the community and the maintainers!

Repository Details

StateMachines Active Record Integration

Build Status Code Climate

StateMachines Active Record Integration

The Active Record 5.1+ integration adds support for database transactions, automatically saving the record, named scopes, validation errors.

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

For the complete usage guide, see http://www.rubydoc.info/github/state-machines/state_machines-activerecord/StateMachines/Integrations/ActiveRecord

Example

class Vehicle < ApplicationRecord
  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 :seatbelt_on, presence: true
    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

State driven validations

As mentioned in StateMachines::Machine#state, you can define behaviors, like validations, that only execute for certain states. One important caveat here is that, due to a constraint in ActiveRecord's validation framework, custom validators will not work as expected when defined to run in multiple states. For example:

class Vehicle < ApplicationRecord
  state_machine do
    state :first_gear, :second_gear do
      validate :speed_is_legal
    end
  end
end

In this case, the :speed_is_legal validation will only get run for the :second_gear state. To avoid this, you can define your custom validation like so:

class Vehicle < ApplicationRecord
  state_machine do
    state :first_gear, :second_gear do
      validate {|vehicle| vehicle.speed_is_legal}
    end
  end
end

Contributing

  1. Fork it ( https://github.com/state-machines/state_machines-activerecord/fork )
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request