Hooks Reference

Overview

Hooks allow you to tap into the application lifecycle and extend functionality.

Lifecycle Hooks

`onInit`

Called when the application initializes.

import { onInit } from 'my-package';

onInit((app) => {
  console.log('App initialized!');
  // Setup code here
});

`onReady`

Called when the application is ready to handle requests.

import { onReady } from 'my-package';

onReady((app) => {
  console.log(`Server running on port ${app.port}`);
});

`onRequest`

Called for every incoming request.

import { onRequest } from 'my-package';

onRequest((request, response, next) => {
  console.log(`${request.method} ${request.url}`);
  next();
});

`onError`

Called when an error occurs.

import { onError } from 'my-package';

onError((error, request, response) => {
  console.error('Error:', error.message);
  response.status(500).json({ error: 'Internal Server Error' });
});

`onShutdown`

Called when the application is shutting down.

import { onShutdown } from 'my-package';

onShutdown(async () => {
  // Cleanup code
  await database.disconnect();
  console.log('Graceful shutdown complete');
});

Event Hooks

`on`

Subscribe to custom events.

import { on, emit } from 'my-package';

// Subscribe
on('user:created', (user) => {
  console.log('New user:', user.name);
  sendWelcomeEmail(user.email);
});

// Emit
emit('user:created', { id: 1, name: 'John', email: 'john@example.com' });

`once`

Subscribe to an event only once.

import { once } from 'my-package';

once('app:ready', () => {
  console.log('This only runs once');
});

`off`

Unsubscribe from an event.

import { on, off } from 'my-package';

const handler = (data) => console.log(data);

on('event', handler);
off('event', handler);

Hook Order

onInit
  ↓
onReady
  ↓
onRequest (per request)
  ↓
onError (if error)
  ↓
onShutdown