Flutter Network Service Discovery (NSD)

A Flutter plugin for discovering network services using NSD (Network Service Discovery) on Android and Bonjour on iOS. This plugin enables your app to find services on a local network.

Features

• Discover services on local networks using mDNS/Bonjour
• Support for both Android and iOS platforms
• Service type filtering
• Automatic service resolution with IP, port, and TXT records
• Debug mode for troubleshooting

Getting Started

Add Dependency

Add the dependency to your pubspec.yaml file:

dependencies:
  lumi_flutter_nsd: ^0.0.1

Platform Configuration

Android

Add the following permissions to your AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

iOS

Add the following to your Info.plist:

<key>NSLocalNetworkUsageDescription</key>
<string>Looking for local network devices</string>
<key>NSBonjourServices</key>
<array>
    <string>_http._tcp.</string>
    <string>_airplay._tcp.</string>
    <!-- Add other service types you want to discover -->
</array>

Usage

Basic Example

import 'package:flutter/material.dart';
import 'package:lumi_flutter_nsd/nsd.dart';

class MyApp extends StatefulWidget {
  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  List<NsdService> services = [];
  bool isDiscovering = false;

  @override
  void initState() {
    super.initState();
    Nsd.setDebug(true);
    addListener();
  }

  @override
  void dispose() {
    stopDiscovery();
    Nsd.dispose();
    super.dispose();
  }

  void addListener() {
    // Listen for found services
    Nsd.serviceFound.listen((service) {
      setState(() {
        services = [...services, service];
      });
    });

    // Listen for discovery start
    Nsd.discoverServiceStarted.listen((_) {
      setState(() {
        isDiscovering = true;
      });
    });

    // Listen for discovery stop
    Nsd.discoverServiceStopped.listen((_) {
      setState(() {
        isDiscovering = false;
      });
    });

    // Listen for discovery failures
    Nsd.discoverServiceFailed.listen((_) {
      setState(() {
        isDiscovering = false;
      });
    });

    // Listen for lost services
    Nsd.serviceLost.listen((service) {
      setState(() {
        services = services.where((s) => s.name != service.name).toList();
      });
    });
  }

  void startDiscovery() async {
    setState(() {
      services = [];
    });
    await Nsd.discoverServices('_airplay._tcp.');
  }

  void stopDiscovery() async {
    await Nsd.stopDiscovery();
  }
}

Events

The plugin provides several event streams:

Event	Description
serviceFound	Emitted when a service is found and resolved
serviceLost	Emitted when a service is no longer available
discoverServiceStarted	Emitted when service discovery starts
discoverServiceStopped	Emitted when service discovery stops
discoverServiceFailed	Emitted when service discovery fails
resolveServiceFailed	Emitted when service resolution fails

Service Information

The NsdService object contains:

class NsdService {
  final String? ip;        // Service IP address
  final int? port;         // Service port
  final String name;       // Service name
  final String type;       // Service type
  final Map<String, dynamic>? attributes;  // TXT records
}

Common Service Types

• _http._tcp. - HTTP services
• _https._tcp. - HTTPS services
• _printer._tcp. - Printer services
• _ipp._tcp. - Internet Printing Protocol
• _airplay._tcp. - AirPlay devices

Error Handling

Enable debug mode to see detailed logs:

Nsd.setDebug(true);

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

License

MIT License - see the LICENSE file for details.