event-emitter-es6

A small event emitter library. Works in the browser and in Node. Can be used with es6 inheritance or as stand-alone lib.

Inspired by the tiny-emitter package on npm.

For more information you can see jsdoc info in index.es6 file.

Very simply applies to express.

Install

Node

npm install event-emitter-es6 --save

Browser

bower install event-emitter-es6 --save

<script src="bower_components/event-emitter-es6/dist/event-emitter.min.js"></script>

or apply via express

var express = require('express');
var app = express();

<... your code here ...>

app.use( require('event-emitter-es6/router') );

<script src="event-emitter-es6/event-emitter.min.js"></script>

Usage

Node

var EventEmitter = require('event-emitter-es6');
var emitter = new Emitter();

emitter.on('some-event', function listener1 (param1, param2, param3) {
  console.info('listener1', param1, param2, param3);
});
emitter.on('some-event', function listener2 (param1, param2, param3) {
  console.info('listener2', param1, param2, param3);
});
emitter.emit('some-event', 'some-val1', 'some-val2', 'some-val3');

Browser

var emitter = new EventEmitter();

emitter.on('some-event', function listener1 (param1, param2, param3) {
  console.info('listener1', param1, param2, param3);
});

emitter.on('some-event', function listener2 (param1, param2, param3) {
  console.info('listener2', param1, param2, param3);
});

emitter.emit('some-event', 'some-val1', 'some-val2', 'some-val3');

ES6

class SomeEmittingClass extends EventEmitter {
  constructor() {
    super();
  }
  
  fireExampleEvent() {
    this.emit('some-event', 'some-val1', 'some-val2', 'some-val3');
  }
}

var emittingInstance = new SomeEmittingClass();

emittingInstance.on('some-event', function listener1 (param1, param2, param3) {
  console.info('listener1', param1, param2, param3);
});
emittingInstance.on('some-event', function listener2 (param1, param2, param3) {
  console.info('listener2', param1, param2, param3);
});
emittingInstance.fireExampleEvent();

Instance Methods

constructor([opts])

An option can be passed to constructor

• opts - settings object for create event emitter
• opts.emitDelay - delay in ms to emit event. If passed 0 - all events emits synchronously. By default = 10
• opts.strictMode - when emit event with no listeners - fires error. By default = false

destroy()

Completely destroys event emitter.

on(event, callback)

Subscribe to an event

• event - the name of the event to subscribe to
• callback - the function to call when event is emitted (for transfer context use bind method of Function.prototype)

once(event, callback)

Subscribe to an event only once

• event - the name of the event to subscribe to
• callback - the function to call when event is emitted (for transfer context use bind method of Function.prototype)

off(event[, callback])

Unsubscribe from an event or all events. If no callback is provided, it unsubscribes you from all events.

• event - the name of the event to unsubscribe from
• callback - the function used when binding to the event. If you used function with bind method - must be passed the same function, that was getted after binding.

emit(event[, ...arguments])

Trigger a named event

• event - the event name to emit
• arguments... - any number of arguments to pass to the event subscribers

emitSync(event[, ...arguments])

Trigger a named event immediate (even the emitter was created as async instance)

• event - the event name to emit
• arguments... - any number of arguments to pass to the event subscribers

Build

Build (Browserifies, and minifies)

npm install
npm run build

Test

Test

npm install
npm run test

Change list

Version 1.1.5

• destroy() method of class

Version 1.1.4

• All code covered with tests