fingerskier / stateinator

state-machine

Usage

• Instantiation

  const StateMachine = require('stateinator')

  const context = {}

  const S = new StateMachine({})

• Setup States

  S.addState('ONE', {
    onEnter: ()=>{
      thing.activate()
    },
    onUpdate: ()=>{
      thing.update()
    },
    onExit: ()=>{
      thing.deactivate()
    },
  })

• Setup Transitions

  S.addTransition('ONE', 'TWO')
  S.addTransition('ONE', 'THREE')
  S.addTransition('TWO', 'ONE')
  S.addTransition('THREE', 'TWO')

• Updating

  S.update()

update will perform any pending transition changes (1 per cycle) and call onUpdate for the current state.

• Goto States

  S.setState('blah')
  
  onButtonClick = ()=> S.goto('flarn')

It is important to call setState initially. The default state is 'void' which you probably don't want to include in your control schema. However, a transition from 'void' is always valid. Note, however, that a transition from a state to itself must be defined.

If you call goto while the machine is changing states then the transition will be queued. In order to proceed with enqueued transitions you need to periodically call update. This is not always relevant- only when you have long-running transition handlers and/or impatient users ;)

TODO

• ?Should transitions also be Map?