AASM - Ruby state machines¶ ↑

This package contains AASM, a library for adding finite state machines to Ruby classes.

AASM started as the acts_as_state_machine plugin but has evolved into a more generic library that no longer targets only ActiveRecord models.

AASM has the following features:

• States

• Machines

• Events

• Transitions

New Callbacks¶ ↑

The only changes I’ve made are creating more callbacks with slightly more obvious semantics ;).

The callback chain & order on a successful event looks like:

oldstate:exit*
event:before
__find transition, if possible__
transition:on_transition*
newstate:enter*
oldstate:before_exit
newstate:before_enter
__update state__
oldstate:after_exit
oldstate:after_enter
event:after
event:success*
obj:aasm_event_fired*

(*) marks old callbacks

Note that the old callbacks haven’t been removed and still have their same semantics. All of this behavior was added without removing any old behavior.

Download¶ ↑

The latest AASM can currently be pulled from the git repository on github.

• github.com/dunedain289/aasm/tree/master

Installation¶ ↑

From GitHub hosted gems¶ ↑

% sudo gem sources -a http://gems.github.com # (you only need to do this once)
% sudo gem install dunedain289-aasm

Building your own gems¶ ↑

% rake gem
% sudo gem install pkg/aasm-2.1.gem

Simple Example¶ ↑

Here’s a quick example highlighting some of the features.

class Conversation
  include AASM

  aasm_initial_state :unread

  aasm_state :unread
  aasm_state :read
  aasm_state :closed

  aasm_event :view do
    transitions :to => :read, :from => [:unread]
  end

  aasm_event :close do
    transitions :to => :closed, :from => [:read, :unread]
  end
end

Other Stuff¶ ↑

Author

Scott Barron <scott at elitists dot net>

License

Original code Copyright 2006, 2007, 2008 by Scott Barron. New changes Copyright 2009 by Scott Petersen. Released under an MIT-style license. See the LICENSE file included in the distribution.

Warranty¶ ↑

This software is provided “as is” and without any express or implied warranties, including, without limitation, the implied warranties of merchantibility and fitness for a particular purpose.