gooostaw / event-emitter

Event emitter ES module ( functions: on, one, off )

event-emitter

Event-emitter is an easy-to-use ES module for web browsers. The library allows you to create event emitters and listeners. Listeners can be switched on and off.

Install

$ npm install --save @gooostaw/event-emitter

Usage

Import:

import EventEmitter from 'event-emitter.js';

Create EventEmitter:

let ee = new EventEmitter();

or create new class and extend EventEmitter:

class Foo extend EventEmitter(){
    //class definition
}

let foo = new Foo();

Create listener and emit events:

//execute on every emit of 'some-event' event
ee.on('some-event', () => console.log('some-event'));
ee.emit('some-event');
ee.emit('some-event');

One-time listener:

//execute only once
ee.one('some-event', () => console.log('some-event'));
ee.emit('some-event');
ee.emit('some-event');

Sending arguments:

//receive an argument from emitter
ee.on('some-event', (argument) => console.log(argument));
ee.emit('some-event', 'abc');

//receive multiple arguments
ee.on('other-event', (arg1, arg2) => console.log(arg1 + arg2));
ee.emit('other-event', 'def', 'ghi');

Listeners can be switched on and off:

let listener = ee.on('some-event', () => console.log('some-event'));
ee.emit('some-event');
listener.off();
ee.emit('some-event'); //this emit will be ignored
listener.on();
ee.emit('some-event');

Remove listeners:

listener.remove(); //remove this listener
ee.clear(); //remove all listeners from this emitter

License

MIT License ©