Node.js Backend Examples for LARC/PAN

This directory contains Node.js versions of the PHP backend examples, making it easier to get started with LARC without requiring PHP.

Available Backends

1. Legacy API (api-legacy.js)

• GET /?x=list_resources - List available database tables
• GET /?x=get&rsc=tablename - Get records from a table (with pagination)
• GET /?x=list_fields&rsc=tablename - Get table schema

2. Secure API (apps/api.js)

• Session-based authentication
• CSRF protection
• Rate limiting
• Resource whitelisting
• SQL injection protection
• Security headers

3. Authentication (auth.js)

• GET /?action=login - User login (returns JWT)
• GET /?action=logout - User logout
• GET /?action=refresh - Refresh JWT token
• GET /?action=check - Check authentication status
• GET /?action=csrf - Get CSRF token

• Email: demo@example.com
• Password: demo123

4. SSE Server (sse.js)

• GET /?topics=topic1,topic2&lastEventId=123 - Subscribe to event stream
• POST / with {"topic": "demo.ping", "data": {...}, "retain": false} - Publish event

Installation

# Install dependencies
npm install

# Or with yarn
yarn install

Usage

Run Individual Servers

# Legacy API
npm run api-legacy

# Secure API
npm run api

# Authentication
npm run auth

# SSE Server
npm run sse

Run All Servers Concurrently

npm run backends

This will start all four servers on their respective ports:

• Legacy API: http://localhost:3000
• Secure API: http://localhost:3001
• Auth: http://localhost:3002
• SSE: http://localhost:3003

Configuration

Create a .env file in this directory with your database settings:

[db]
type=mysql
host=localhost
user=root
pass=
db=test

# For SQLite (optional)
# type=sqlite
# file=pan_demo.db

[demo]
mode=true

[security]
jwt_secret=change-this-secret-in-production

Database Support

Both MySQL and SQLite are supported:

• MySQL: Use the mysql2 package (already included)
• SQLite: Use the better-sqlite3 package (already included)

Security Notes

Development vs Production

The examples are configured for development use. For production:

Password Hashing

The authentication server uses bcryptjs for password hashing. The demo password is pre-hashed for convenience.

Comparison with PHP Versions

| Feature | PHP Version | Node.js Version | |---------|-------------|-----------------| | No build step | ✓ | ✓ | | MySQL support | ✓ | ✓ | | SQLite support | ✓ (PDO) | ✓ (better-sqlite3) | | Sessions | ✓ (built-in) | ✓ (in-memory Map) | | CSRF protection | ✓ | ✓ | | Rate limiting | ✓ | ✓ | | JWT support | ✓ (manual) | ✓ (crypto) | | SSE | ✓ (file-based) | ✓ (file-based + in-memory) |

Examples

Fetch Resources

// Get list of available resources
const response = await fetch('http://localhost:3000/?x=list_resources');
const data = await response.json();
console.log(data.Resources);

Get Data with Pagination

// Get first 10 products
const response = await fetch('http://localhost:3000/?x=get&rsc=products&page_size=10&start=0');
const data = await response.json();
console.log(data.results);

Authenticate

// Login
const response = await fetch('http://localhost:3002/?action=login', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    email: 'demo@example.com',
    password: 'demo123'
  })
});
const data = await response.json();
console.log(data.token);

Subscribe to SSE

const events = new EventSource('http://localhost:3003/?topics=demo.*');

events.addEventListener('demo.ping', (e) => {
  const data = JSON.parse(e.data);
  console.log('Received:', data);
});

Publish SSE Event

await fetch('http://localhost:3003/', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    topic: 'demo.ping',
    data: { message: 'Hello from Node.js!' },
    retain: false
  })
});

Troubleshooting

Port Already in Use

If you get an "EADDRINUSE" error, another process is using the port. Either:

Database Connection Errors

• Check your .env configuration
• Ensure MySQL is running (if using MySQL)
• Verify database credentials
• Create the database if it doesn't exist

Module Not Found

Run npm install to install all dependencies.

License

MIT © LARC Contributors