Big machine

Big machine is a Gem which give state to your object

Resources

Bugs

• http://github.com/alaibe/big_machine/issues

Development

• http://github.com/alaibe/big_machine

Testing

• http://travis-ci.org/alaibe/big_machine

Source

• git://github.com/alaibe/big_machine.git

Install

Add this to your Gemfile

  gem 'big_machine'

Usage

Create your first state

  class Draft < BigMachine::State
    def publish
      transition_to Online
    end
  end

  class Online < BigMachine::State
  end

All methods you override in you state can takes args and block

  class Draft < BigMachine::State
    def publish(now = Time.now)
      transition_to Online, now
    end
  end

  class Online < BigMachine::State
    def enter(*args)
      stateful.publish_at args.first
    end
  end

Make your object stateful

  class Car
    include BigMachine

    big_machine initial_state: :draft
  end

Now it's possible to publish your car object:

  car = Car.new
  car.current_state # => Draft
  car.publish
  car.current_state # => Online

Of course your object can be an ActiveRecord::Base object. In this case, the object must have a state column. ( if not, see the next section )

Big machine options

big_machine method can take several options:

• initial_state is the only one necessary option
• state_attribute is available only if the object is an active record object
• workflow if you want to change the normal worklow It's possible to call workflow_is method in your different states

Example

  big_machine initial_state: :dradt, state_attribute: :big_state, workflow: small

  class Draft < BigMachine::State

    def publish
      return if workflow_is :small

      transition_to Online
    end

  end

Lock module

A state can include lock module, it will lock the state of your object when your enter in it. The unlock method should be call to unlock the module

  class Draft < BigMachine::State
    include BigMachine::Lock

    def publish
      transition_to Online
    end

  end

  class Article
    include BigMachine

    big_machine initial_state: :dradt
  end

  article = Article.new
  article.publish
  article.current_state # => Draft
  article.unlock
  article.publish
  article.current_state # => Online

Contributors

*Anthony Laibe