Solo Tab Enforcer

A comprehensive, cross-browser solution for enforcing single tab usage in web applications. Built with pure JavaScript using native browser APIs with intelligent fallback strategies.

Features

• ✅ Cross-browser compatibility - Works in all modern browsers and legacy IE
• 🔧 Zero dependencies - Pure JavaScript using native browser APIs
• 🛡️ Multiple enforcement strategies - BroadcastChannel, localStorage, visibility API, and fallbacks
• ⚡ High performance - Optimized for minimal resource usage
• 🎛️ Fully configurable - Extensive options for customization
• 📱 Mobile support - Works on mobile browsers and PWAs
• 🔍 Debug mode - Comprehensive logging for troubleshooting

Installation

NPM

npm install solo-tab-enforcer

Direct Download

<script src="https://unpkg.com/solo-tab-enforcer/dist/solo-tab-enforcer.min.js"></script>

Quick Start

// Basic usage
const enforcer = new SoloTabEnforcer();
enforcer.init();

// With options
const enforcer = new SoloTabEnforcer({
  debug: true,
  checkInterval: 1000,
  warningMessage: 'Another tab is already open!',
  onTabConflict: (existingTab) => {
    console.log('Conflict with tab:', existingTab.id);
    window.close();
  }
});

enforcer.init();

Configuration Options

Option	Type	Default	Description
storageKey	string	'solo-tab-enforcer'	Storage key for tab coordination
checkInterval	number	1000	Interval for conflict checking (ms)
warningMessage	string	'Another tab is already open...'	Default warning message
redirectUrl	string	null	URL to redirect conflicting tabs
allowMultipleTabs	boolean	false	Allow multiple tabs globally
debug	boolean	false	Enable debug logging
onTabConflict	function	null	Callback when tab conflict occurs
onTabActivated	function	null	Callback when tab becomes active
onTabDeactivated	function	null	Callback when tab becomes inactive
useVisibilityAPI	boolean	true	Use Page Visibility API
useBroadcastChannel	boolean	true	Use BroadcastChannel API
useStorageEvents	boolean	true	Use storage events
tabTimeoutMs	number	5000	Tab timeout for cleanup (ms)

API Reference

Methods

init()

Initialize the tab enforcer. Must be called after instantiation.

destroy()

Destroy the enforcer and clean up resources.

getTabInfo()

Get detailed information about the current tab.

areMultipleTabsAllowed()

Check if multiple tabs are currently allowed.

allowMultipleTabs()

Enable multiple tabs (disable enforcement).

disallowMultipleTabs()

Disable multiple tabs (enable enforcement).

forceRegister()

Force register the current tab (useful for recovery).

Static Methods

SoloTabEnforcer.create(options)

Create a new instance with options.

SoloTabEnforcer.createAndInit(options)

Create and immediately initialize an instance.

SoloTabEnforcer.checkSupport()

Check browser feature support.

SoloTabEnforcer.getBrowserInfo()

Get browser information.

Browser Support

Browser	Version	Status
Chrome	60+	✅ Full support
Firefox	55+	✅ Full support
Safari	10+	✅ Full support
Edge	16+	✅ Full support
IE	11+	⚠️ Fallback mode

Examples

Basic Implementation

const enforcer = new SoloTabEnforcer({
  debug: true,
  onTabConflict: () => {
    alert('Another tab is already open!');
    window.close();
  }
});

enforcer.init();

Advanced Configuration

const enforcer = new SoloTabEnforcer({
  checkInterval: 500,
  tabTimeoutMs: 10000,
  redirectUrl: '/single-tab-warning.html',
  onTabActivated: () => console.log('Tab activated'),
  onTabDeactivated: () => console.log('Tab deactivated'),
  onTabConflict: (existingTab) => {
    console.log('Conflict with tab:', existingTab);
    // Custom conflict handling
  }
});

enforcer.init();

Conditional Enforcement

const enforcer = new SoloTabEnforcer();

// Enable enforcement only for certain users
if (user.requiresSingleTab) {
  enforcer.disallowMultipleTabs();
} else {
  enforcer.allowMultipleTabs();
}

enforcer.init();

How It Works

The Solo Tab Enforcer uses a multi-layered approach:

1. Primary Strategy: BroadcastChannel API for modern browsers
2. Secondary Strategy: localStorage with storage events
3. Fallback Strategy: Polling with various detection methods
4. Legacy Support: Cookie-based coordination for older browsers

Performance

• Memory Usage: < 50KB
• CPU Impact: Minimal (configurable intervals)
• Network: Zero external requests
• Startup Time: < 5ms initialization

Security

• No external dependencies
• No data transmission
• Local storage only
• No cookies (unless fallback)

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines.

Support

For issues and questions, please use the GitHub issue tracker.