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:
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States
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Machines
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Events
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Transitions
The callback chain & order on a successful event looks like:
oldstate:exit* event:before __find transition, if possible__ transition:on_transition* oldstate:before_exit newstate:before_enter newstate:enter* __update state__ event:success* oldstate:after_exit newstate:after_enter event:after obj:aasm_event_fired* (*) marks old callbacks
The latest AASM can currently be pulled from the git repository on github.
% sudo gem install gemcutter % sudo gem tumble % sudo gem install aasm
% sudo gem sources -a http://gems.github.com # (you only need to do this once) % sudo gem install rubyist-aasm
% rake gemspec % rake build % sudo gem install pkg/aasm-2.1.gem
Here’s a quick example highlighting some of the features.
class Conversation include AASM aasm_column :current_state # defaults to aasm_state 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
This example uses a few of the more complex features available.
class Relationship include AASM aasm_column :status aasm_initial_state Proc.new { |relationship| relationship.strictly_for_fun? ? :intimate : :dating } aasm_state :dating, :enter => :make_happy, :exit => :make_depressed aasm_state :intimate, :enter => :make_very_happy, :exit => :never_speak_again aasm_state :married, :enter => :give_up_intimacy, :exit => :buy_exotic_car_and_wear_a_combover aasm_event :get_intimate do transitions :to => :intimate, :from => [:dating], :guard => :drunk? end aasm_event :get_married do transitions :to => :married, :from => [:dating, :intimate], :guard => :willing_to_give_up_manhood? end def strictly_for_fun?; end def drunk?; end def willing_to_give_up_manhood?; end def make_happy; end def make_depressed; end def make_very_happy; end def never_speak_again; end def give_up_intimacy; end def buy_exotic_car_and_wear_a_combover; end end
- Author
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Scott Barron <scott at elitists dot net>
- License
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Original code Copyright 2006, 2007, 2008 by Scott Barron. Released under an MIT-style license. See the LICENSE file included in the distribution.
This software is provided “as is” and without any express or implied warranties, including, without limitation, the i 549D mplied warranties of merchantibility and fitness for a particular purpose.