intro

a small event emitter class

installation

npm install --save @jrc03c/emitter

usage

import { Emitter } from "@jrc03c/emitter"

const emitter = new Emitter()

emitter.on("random-number", v => {
  console.log(v)
})

emitter.emit("random-number", Math.random())

api

Emitter

Emitter() (constructor)

takes no arguments.

properties

subscriptions

an object whose key-value pairs represent channel names and arrays of callbacks, respectively.

methods

emit(channel, value1, value2, value3, ...)

calls all of the callbacks subscribed to channel and passes to them as arguments the values value1, value2, value3, ...

off(channel, callback)

unsubscribes callback from channel.

on(channel, callback)

subscribes callback to channel. returns a function that, when called, will unsubscribe callback from channel. for example:

import { Emitter } from "@jrc03c/emitter"

const emitter = new Emitter()

const unsubscribe = emitter.on("just-once", () => {
  console.log("once!")
  unsubscribe()
})

for (let i = 0; i < 100; i++) {
  emitter.emit("just-once")
}