state_machine_history

state_machine_history is an extension of the state_machine gem, that logs transitions between states and allows to check if a state was visited earlier.

Install

gem install state_machine_history

Ruby On Rails 2.x

Add the gem dependency to environment.rb:

...
config.gem 'state_machine_history'
...

Generate the migration:

script/generate state_machine_history_2 create_machine_history

Run the migration

rake db:migrate

Ruby On Rails 3

In Gemfile:

gem 'state_machine_history'

Generate the migration:

rails generate state_machine_history create_machine_history

Run the migration:

rake db:migrate

Usage

This gem adds logging function to the state_machine gem. Sample:

Class definition

class Order
  state_machine :initial => :not_selected do
    # Switch on state machine logging 
    track_history

    event :choose do
      transition :not_selected => :selected
    end
    event :add_to_basket do
      transition :selected => :in_basket
    end
    event :pay do
      transition :in_basket => :paid
    end
    event :to_send do
      transition :paid => :sent
    end
  end
end

Using extensions

order = Order.new
# Perform transition (state change is logged)
order.choose
# Find whether order has visited not_selected state before selected one
order.was_there?(:not_selected, :selected) #=> true
# Find whether order has visited not_selected state before the current one
order.was_there?(:not_selected)  #=> true

Credits

Project Team

Mykhaylo Sorochan - Project Manager
Dmitriy Landberg - Software Developer
Nataliya Shatokhina - Tester
Sergey Mostovoy - Extension idea