AlterEgo-Mongoid

Motivation

AlterEgo is my favorite Ruby state machine for the following reasons:

1. It's not dependent on Mongoid - it can be used on plain Ruby objects.
2. It most closely follows the GOF State Pattern because it allows for 
 polymorphic behavior based on state.

Out of the box, AlterEgo doesn't play nicely with Mongoid because it stores state in @state, whereas Mongoid::Document persists with setter methods.

This mixin overrides the AlterEgo's accessor methods for state to allow it to be properly persisted to a database, as well as serialized/unserialized as json, yml, and xml.

Installation

As a Ruby Gem

gem install alter-ego gem install alter-ego-mongoid

OR using Rails 3 Bundle

gem 'alter-ego', :require => 'alter_ego' gem 'alter-ego-mongoid', :require => 'alter_ego/mongoid_adapter'

OR as a Rails plugin

script/plugin install git://github.com/wink/alter-ego-mongoid.git

Usage

This plugin automatically adds a string field to your model called "state".

# you'll only need the following two lines if you're NOT using
# alter-ego-mongoid as a plugin
gem 'alter-ego-mongoid'
require 'alter_ego/mongoid_adapter'

class Example
include Mongoid::Document
include AlterEgo # include this first
include AlterEgo::MongoidAdapter

# Your code here
end