GeoFencing Library

A lightweight and easy-to-use geofencing library for monitoring user location relative to defined geographical areas. Perfect for location-based notifications, tracking, and triggers in web applications.

Features

• 🌍 Create circular geofences with custom radius
• 📍 Monitor multiple geographical areas simultaneously
• 🎯 Custom callbacks for enter/exit events
• 📱 Built-in geolocation monitoring
• 🛡️ Error handling and validation
• 📦 Zero dependencies

Installation

npm install geofencing-js

Quick Start

import GeoFencingManager from 'geofencing-js';

// Create a manager instance
const geoManager = new GeoFencingManager();

// Add a geofence
geoManager.addFence({
  id: 'store-123',
  latitude: 40.7128,
  longitude: -74.0060,
  radius: 100,  // meters
  onEnter: (id) => console.log(`Entered zone ${id}`),
  onExit: (id) => console.log(`Left zone ${id}`)
});

// Start monitoring
geoManager.startLocationMonitoring();

Usage

Single Fence

const fence = {
  id: 'store-123',
  latitude: 40.7128,
  longitude: -74.0060,
  radius: 100,
  onEnter: (id) => console.log(`Entered ${id}`),
  onExit: (id) => console.log(`Left ${id}`)
};

geoManager.addFence(fence);

Multiple Fences

const locations = [
  {
    id: 'store-a',
    coords: [40.7128, -74.0060, 100]  // [latitude, longitude, radius]
  },
  {
    id: 'store-b',
    coords: [40.7580, -73.9855, 100]
  }
];

geoManager.monitorCoordinates(locations, (id) => {
  console.log(`Entered area: ${id}`);
});

API Reference

GeoFencingManager

Constructor

const geoManager = new GeoFencingManager();

Methods

addFence(config)

Adds a new geofence to monitor.

• Parameters:
  • config (Object):
    • id (String): Unique identifier
    • latitude (Number): Fence center latitude
    • longitude (Number): Fence center longitude
    • radius (Number): Radius in meters
    • onEnter (Function): Callback when entering fence
    • onExit (Function): Callback when exiting fence

monitorCoordinates(coordsList, onEnterCallback)

Monitors multiple locations simultaneously.

• Parameters:
  • coordsList (Array): Array of location objects
  • onEnterCallback (Function): Global callback for all fence entries

startLocationMonitoring()

Starts monitoring user location.

stopMonitoring()

Stops location monitoring.

Browser Support

The library uses the Geolocation API and requires browser support for:

• Geolocation API
• ES6 Classes
• Promises

Error Handling

The library includes built-in error handling for:

• Geolocation API unavailability
• Invalid coordinates
• Missing required parameters
• Position tracking errors

Example Use Cases

• Retail: Send notifications when customers are near stores
• Tourism: Trigger audio guides near points of interest
• Delivery: Track drivers in delivery zones
• Events: Monitor attendee locations at large venues

License

MIT License

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.