fsm-event

Stateful finite state machine wrapper around fsm.

Installation

$ npm install fsm-event

Usage

const fsm = require('fsm-event')

const m = fsm({
  START: {
    data: 'START',
    pause: 'PAUSED',
    end: 'END',
    error: 'ERROR'
  },
  PAUSED: {
    pause: 'PAUSED',
    resume: 'START',
    error: 'ERROR'
  },
  ERROR: {},
  END: {}
})

m.on('PAUSED', () => console.log('paused state!'))
m.on('PAUSED:enter', cb => cb())
m.on('PAUSED:leave', cb => cb())

m('START')

API

const m = fsm(events)

Create a state machine.

m.on(event, cb)

Attach a listener to the state machine.

m(event)

Trigger an event on the state machine. Must be a valid state defined on init. Alias: m.emit(event).

Events

Each state triggers 3 events. important: When listening to :enter or :leave events, the callback must be called so that the state machine can proceed to the next state.

<state>         main state function 
<state>:enter   called when transitioning into state
<state>:leave   called when transitioning away from state

Why?

Most state machines have overly complicated interfaces for managing state. The fsm state machine is stateless, so I wrote a stateful wrapper around it. This allows me to managage application state without creating complex branches; my direct use case for this was building stateful UI elements.

See Also

• fsm - Finite State Machines in javascript
• machina.js - js ex machina - finite state machines in JavaScript
• javascript-state-machine - A finite state machine javascript micro framework
• SimpleStateManager - browser width state manager

License

MIT