A simple event emitter implemention, support `on`/`off`/`emit` methods.
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/428695/945691/CKEventEmitter.js
// ==UserScript==
// @name CKEventEmitter
// @namespace eventemitter.ckylin.site
// @version 0.1
// @author CKylinMC
// @grant unsafeWindow
// @license GPLv3 License
// ==/UserScript==
class EventEmitter {
handlers = {};
on(name, func) {
if (!(func instanceof Function)) throw "Param must be func!";
if (!(name in this.handlers)) {
this.handlers[name] = [];
}
this.handlers[name].push(func);
}
off(name, func) {
if (!(func instanceof Function)) throw "Param must be func!";
if (name in this.handlers) {
for (let i = 0; i < this.handlers[name].length; i++) {
if (this.handlers[name][i] === func) {
this.handlers[name].splice(i, 1);
i--;
}
}
}
}
emit(name, ...args) {
if (name in this.handlers) {
for (let func of this.handlers[name]) {
try {
func(...args);
} catch (e) {
console.error('ERROR:', e);
}
}
}
}
}