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

        - enter
        - exit
  

• Machines
• Events

        - name
        - success -> callback
        - transitions block
  

• Transitions

        - from
        - to
        - on_transition -> callback
        - guard (returns true or false)
  

• Callbacks

        - aasm_before_all_transition -> callback before transition begins
        - aasm_after_all_transition -> callback after transition ends
  

• default and specific log features

        - aasm_log_transition -> instance variable that determines whether to log or not. Defaults to true
        - aasm_log_method -> the method name for common logging name. Defaults to: aasm_log_transition
        - aasm_<event_name>_log -> if you want to have a specific log for one particular event
                                  just implement a method with this naming convention: aasm_<event_name>_log
        - aasm also provided the event name, from state and to state to the instance by populating there instance variables:
                self.aasm_event_name, self.aasm_old_state, self.aasm_new_state
  

• transaction if we choose to persist the transition
• By including AASM, you will have access to these instance methods:

        - <state_name>? -> check if the model is in that state
        - aasm_current_state -> returns the current state of model
        - <event_name>! -> behaves like save!
        - <event_name>  -> behaves like save
        - <event_name>_not_persist -> doesn't save to database
        - aasm_events_for_state -> all events that include the passed state in the from transitions
        - aasm_events_for_current_state -> all events that include the current state in the from transitions
  

• By including AASM, you will have access to these class methods:

        - aasm_states_for_select -> returns options for all states defined
  

Download

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

• github.com/mumboe/aasm

A release and a gem are forthcoming.

Installation

From GitHub hosted gems

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

Building your own gems

  % rake gem
  % sudo gem install pkg/aasm-0.0.2.gem

Simple Example

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

  class Conversation
    include AASM

    aasm_initial_state :new

    aasm_state :new
    aasm_state :read
    aasm_state :closed

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

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

Other Stuff

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.