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StateJacket JS

Based on StateJacket by hopsoft.

An Intuitive State Transition System for JavaScript

State machines are awesome but can be pretty daunting as a system grows. Keeping states, transitions, & events straight can be tricky. StateJacket simplifies things by isolating the management of states & transitions. Events are left out, making it much easier to reason about what states exist and how they transition to other states.

The examples below are somewhat contrived, but should clearly illustrate the usage.

The Basics


$ npm install state-jacket

Define states & transitions for a simple turnstyle.


var StateJacket = require('state-jacket');
var states = new StateJacket.Catalog();
states.add('open', 'closed', 'error');
states.add('closed', 'open', 'error');
states.transitioners(); // => ['open', 'closed'] 
states.terminators(); // => ['error'] 
states.canTransition('open', 'closed'); // => true 
states.canTransition('closed', 'open'); // => true 
states.canTransition('error', 'open'); // => false 
states.canTransition('error', 'closed'); // => false