@zodash/event/lib/index.js

event emitter

"use strict";
var _a;
Object.defineProperty(exports, "__esModule", { value: true });
exports.EventEmitter = exports.Event = void 0;
const once_1 = require("@zodash/once");
const LISTENERS = Symbol('listeners');
class Event {
    constructor() {
        this[_a] = {};
    }
    get listeners() {
        return this[LISTENERS];
    }
    on(event, listener) {
        if (!this.listeners[event]) {
            this.listeners[event] = [];
        }
        this.listeners[event].push(listener);
        return this;
    }
    off(event, listener) {
        if (this.listeners[event]) {
            const all = this.listeners[event];
            all.splice(all.indexOf(listener), 1);
        }
        return this;
    }
    once(event, listener) {
        if (!this.listeners[event]) {
            this.listeners[event] = [];
        }
        this.listeners[event].push(once_1.once(listener));
        return this;
    }
    emit(event, ...args) {
        if (this.listeners[event]) {
            const partListeners = this.listeners[event];
            partListeners.forEach((listener) => {
                if (event === 'error') {
                    return listener.apply(this, args);
                }
                try {
                    listener.apply(this, args);
                }
                catch (error) {
                    this.emit('error', error);
                }
            });
            return this;
        }
        // if no error listener, just throw
        if (event === 'error') {
            if (args[0] instanceof Error) {
                throw args[0];
            }
            throw new Error(String(args[0]));
        }
        return this;
    }
    addListener(event, listener) {
        return this.on(event, listener);
    }
    removeListener(event, listener) {
        return this.off(event, listener);
    }
    removeAllListeners(event) {
        if (this.listeners[event]) {
            delete this.listeners[event];
        }
        return this;
    }
}
exports.Event = Event;
_a = LISTENERS;
// alias of Event
exports.EventEmitter = Event;