Skip to main content

Node.js Event Emitter

The default in-memory event system using Node.js built-in EventEmitter.

Included in Base Preset

This plugin is part of the base preset and loaded automatically. Using the base preset is strongly recommended, so explicit installation is usually not required.

Installation​

import '@unchainedshop/plugins/events/node-event-emitter';

This plugin automatically calls setEmitAdapter() when imported, making it the active event system immediately.

Features​

  • In-Memory: Events are handled within the same process
  • High Performance: Fast event handling with no network overhead
  • Simple Setup: No external dependencies required
  • Development Friendly: Perfect for development and testing
  • Synchronous: Events are processed synchronously within the process

Use Cases​

  • Single Instance Deployments: Applications running on a single server
  • Development Environment: Local development and testing
  • Simple Applications: Applications without complex scaling requirements
  • Real-time Processing: When low latency is critical

Limitations​

  • Single Process: Events don't cross process boundaries
  • No Persistence: Events are lost if the process crashes
  • Memory Usage: All listeners are kept in memory
  • No Distribution: Cannot scale across multiple instances

Usage​

Publishing Events​

import { emit } from '@unchainedshop/events';

await emit('ORDER_CREATE', {
  orderId: '12345',
  userId: 'user123',
  total: 99.99
});

Subscribing to Events​

import { subscribe } from '@unchainedshop/events';

subscribe('ORDER_CREATE', async (payload) => {
  const { orderId, userId, total } = payload;
  await sendOrderConfirmationEmail(userId, orderId);
});

When to Use​

Use the Node.js Event Emitter for:

  • Local development
  • Testing environments
  • Simple applications
  • Single server deployments
  • When Redis/cloud setup is not feasible

Adapter Details​

PropertyValue
Sourceevents/node-event-emitter.ts