@web-loom/event-emitter-core

Type-safe event emitter shared across the Web Loom packages. This utility replaces the ad-hoc emitters that previously lived in forms-core, notifications-core, media-core, and storage-core.

Installation

npm install @web-loom/event-emitter-core

Quick start

import { EventEmitter } from '@web-loom/event-emitter-core';

type MediaEvents = {
  play: void;
  progress: [currentTime: number, duration: number];
  error: Error;
};

const emitter = new EventEmitter<MediaEvents>();
const cleanup = emitter.on('progress', (current, total) => {
  console.log(`${current}/${total}`);
});

emitter.emit('progress', 16, 100);
cleanup();

API surface

• on(event, listener) – register a listener and get an unsubscribe callback.
• once(event, listener) – same as on but automatically unsubscribes after the first emission.
• off(event?, listener?) – remove a specific listener, all listeners for an event, or everything.
• emit(event, ...payload) – synchronously fan out the payload.
• removeAllListeners(event?)/removeAll()/clear() – cleanup helpers.
• listenerCount(event), hasListeners(event), eventNames() – runtime inspection helpers.
• subscribe/unsubscribe/unsubscribeAll – compatibility aliases for legacy packages.

Errors thrown by listeners are caught and forwarded to console.error by default. Pass new EventEmitter({ onError }) if you want to override that behavior.

Package relationships

| Package | Usage | | ------------------------------ | ------------------------------------------------------------- | | @web-loom/forms-core | Debounced form events and lifecycle hooks. | | @web-loom/storage-core | Key-pattern subscriptions for cross-tab storage updates. | | @web-loom/notifications-core | Permission / push event fan-out. | | @web-loom/media-core | Player lifecycle events (play, pause, lazy loading, plugins). | | @web-loom/event-bus-core | Internal listener bookkeeping for the public bus API. |

See docs/event-emitter.md in the repo root for package‑specific integration notes.