state_machine

https://github.com/pluginaweek/state_machine

Ruby

Adds support for creating state machines for attributes on any Ruby class

StateMachine::StateCollection#match!

Determines the current state of the given object as configured by this
state machine.  If no state is found, then an ArgumentError will be
raised.

== Examples

  class Vehicle
    state_machine :initial => :parked do
      other_states :idling
    end
  end
  
  states = Vehicle.state_machine.states
  
  vehicle = Vehicle.new         # => #<Vehicle:0xb7c464b0 @state="parked">
  states.match!(vehicle)        # => #<StateMachine::State name=:parked value="parked" initial=true>
  
  vehicle.state = 'invalid'
  states.match!(vehicle)        # => ArgumentError: "invalid" is not a known state value

Source | Google | Stack overflow

Edit

git clone [email protected]:pluginaweek/state_machine.git
cd state_machine
open lib/state_machine/state_collection.rb

Contribute

# Make a new branch
git checkout -b -your-name--update-docs-StateMachine--StateCollection-match--for-pr

# Commit to git
git add lib/state_machine/state_collection.rbgit commit -m "better docs for StateMachine::StateCollection#match!"

# Open pull request
gem install hub # on a mac you can `brew install hub`
hub fork
git push <your name> -your-name--update-docs-StateMachine--StateCollection-match--for-pr
hub pull-request

# Celebrate!