WS: Cross-Platform WebSocket Client

The ws package provides a comprehensive WebSocket client library for Dart and Flutter applications, enabling seamless communication with WebSocket servers across multiple platforms.

Features

• Cross-platform WebSocket client
• Automatic reconnection with customizable backoff strategy
• JSON message decoding
• WebSocket metrics tracking
• Extensible with interceptors (middlewares)
• Secure WebSocket connections (wss://)
• Customizable connection options for both VM and JS platforms

Installation

Add the following dependency to your pubspec.yaml file:

dependencies:
  ws: 

Usage

import 'package:ws/ws.dart';

void main() async {
  final ws = WebSocket('ws://echo.websocket.org');
  
  ws.connect().then((_) {
    ws.stream.listen((message) {
      print('Received message: $message');
    });
    
    ws.add('Hello WebSocket!');
  });
}

Reconnect with Delay

Implement a simple Exponential Backoff (with Jitter) strategy with full jitter or Fixed Interval strategy with optional jitter.

import 'package:ws/ws.dart';

void main() async {
  // Full Jitter strategy
  final ws = WebSocket('ws://echo.websocket.org',
    connectionRetryInterval: const WebSocketRetryInterval(
      minDelay: Duration(seconds: 1),
      maxDelay: Duration(seconds: 10),
    ),
  );
  
  ws.connect().then((_) {
    ws.stream.listen((message) {
      print('Received message: $message');
    });
    
    ws.add('Hello WebSocket!');
  });
}

Platform-Specific Options

• VM: Customize the client with WebSocketOptions.vm()
• JS: Customize the client with WebSocketOptions.js()

Interceptors (Middlewares)

Add custom pre-processing or post-processing logic to the WebSocket stream.

void main() async {
  final ws = WebSocket('ws://echo.websocket.org',
    interceptors: [
      WsLogInterceptor(logger: print),
      WsJsonEncodeInterceptor(),
    ],
  );
  
  ws.connect().then((_) {
    ws.stream.listen((message) {
      print('Received message: $message');
    });
    
    ws.add('Hello WebSocket!');
  });
}

Conclusion

The ws package offers a robust and versatile WebSocket client solution for Dart and Flutter applications. Its comprehensive features, such as reconnection, JSON decoding, metrics, and interceptors, make it an indispensable tool for building real-time communication applications.