@bemoje/emitterize

Upgrade a class to become an EventEmitter without extending. Uses the 'eventemitter3' module, but there are some major differences in terms of syntax-logic. EventName strings are out. Instead of emitter.on('end', fn), you just do emitter.onEnd(fn). When the main exported method is called, you provide all the event-names, from which 'onEnd' is created. Internally, a normal UNCHANGED emitter instance is created and used. Handling of eventNames is automatic (and uses symbols which performs faster), and you don't have to do any of it yourself. It is all on your own class's prototype, so it's inheritable. The only thing done on the instance, is setting the (hidden) actual EventEmitter object there. Nothing else is done on your instances. It works the same way with all the eventName-specific methods. onEnd(fn), onceEnd, emitEnd(data, ctx)... etc.

• version 0.0.1
• author Benjamin Moller Jensen [email protected]
• date July, 2020

install

npm install --save @bemoje/emitterize

Docs

export function emitterize(Class: Function): Function

Class.defineEvents = function(...eventNames: Array<string>): Function

usage

import emitterize from '@bemoje/emitterize'

// normal class
let Cool = class {
	constructor() {
		this.a = 5
	}
	hey() {
		this.emitStart('now starting')
	}
}

// it happens here
Cool = emitterize(Cool).defineEvents('end', 'start', 'error')

// now test
const ins = new Cool()

ins.onStart((data) => {
	console.log(data)
})

ins.hey()
//=> event: "now starting"