beyond/lib/utils/ipc/main/events/index.js

The Full Stack Universal Typescript Framework

module.exports = class {
    // Sources of events are the events received from the forked processes
    #sources;
    #listeners = new Map;

    constructor() {
        this.#sources = new (require('./sources'))(this.#listeners);
    };


    on(source, event, listener) {
        if (typeof source !== 'string' || typeof event !== 'string' || typeof listener !== 'function') {
            throw new Error('Invalid parameters');
        }

        let listeners;
        const key = `${source}|${event}`;
        if (this.#listeners.has(key)) {
            listeners = this.#listeners.get(key);
        }
        else {
            listeners = new Set;
            this.#listeners.set(key, listeners);
        }
        listeners.add(listener);
    }

    off(source, event, listener) {
        const key = `${source}|${event}`;

        let listeners;
        if (!this.#listeners.has(key)) {
            console.warn(`No listeners registered with key "${key}"`);
            return;
        }

        listeners = this.#listeners.get(key);
        if (!listeners.has(listener)) {
            console.warn(`The specified listener is not registered with key "${key}"`);
            return;
        }

        listeners.delete(key, listener);
    }

    // To emit events from the main to the forked children and even to the main process
    emit(event, message) {
        this.#sources.emit('main', event, message);
    };

    /**
     * Register a fork process to hear for actions requests
     * @param name {string} The name assigned to the forked process
     * @param fork {object} The forked process
     */
    registerFork = (name, fork) => this.#sources.register(name, fork);
}