state_machine

https://github.com/pluginaweek/state_machine

Ruby

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

StateMachine::Event#on_failure

Marks the object as invalid and runs any failure callbacks associated with
this event.  This should get called anytime this event fails to transition.

Source | Google | Stack overflow

Edit

git clone [email protected]:pluginaweek/state_machine.git

cd state_machine

open lib/state_machine/event.rb

Contribute

# Make a new branch

git checkout -b -your-name--update-docs-StateMachine--Event-on_failure-for-pr

# Commit to git

git add lib/state_machine/event.rbgit commit -m "better docs for StateMachine::Event#on_failure"

# 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--Event-on_failure-for-pr

hub pull-request

# Celebrate!