evenity

Unified event attachment utility

Features

• Attach event to any kind of event-enabled object
• Same event API for both node-like event emitter instance and html element
• Return a closable object to detach event

Getting Started

Install the module with: npm install --save evenity

var evenity = require('evenity')
var EventEmitter = require('events').EventEmitter

var el = document.createElement('div')
var obj = new EventEmitter()

function handler(event) {
  // ...
  // event.detail contain the emitted datas
}

// Attach event on any eventemitter-kind object
var eventOnElement = evenity.on(el, 'myevent', handler)
var eventOnObject = evenity.on(obj, 'myevent', handler)

// Attach event once
evenity.once( /* ... */ )

// Detach event
evenity.off(el, 'myevent', handler)
evenity.off(obj, 'myevent', handler)

// Emit event
evenity.emit(el, 'click', {foo:'bar'})
//  {foo:'bar'} is the detail of the CustomEvent for HTMLElement

// Detach event using close method returned by evenity
eventOnElement.close()
eventOnObject.close()

API

evenity.on()

evenity.on({EventEmitter|HTMLElement} obj, {String} eventname, {Function} handler) => {Object} closable

Attach an event handler to an object. If obj is an HTMLElement the handler will receive an event object. Else, handler receive the emitted data.

The returned closable object has a closable.close() method to detach the handler:

var e = evenity.on(obj, 'eventname', function(event) { /* handle event.detail */ } )
e.close() // Detach event handler

evenity.once()

evenity.once({EventEmitter|HTMLElement} obj, {String} eventname, {Function} handler)

Same as evenity.on() but the handler is called only once, then the event is automatically detached

evenity.off()

evenity.off({EventEmitter|HTMLElement} obj, {String} eventname, {Function} handler)

Detach an event handler

evenity.emit()

evenity.emit({EventEmitter|HTMLElement} obj, {String|CustomEvent} eventnameOrCustomEvent, [{mixed|Event} data])

Emit an event. If obj is an HTMLElement, then a CustomEvent is emitted with data as detail. If data is a window.Event instance then

evenity.emit(el, 'myEvent', { foo: 'bar' })
evenity.emit(el, new CustomEvent('myEvent', { detail: {}, bubbles: true, cancelable: true }))
var canceled = !evenity.emit(el, new MouseEvent('click', { view: window, bubbles: true, cancelable: true }))

The MIT License