WSTalk

Library providing a natural interface to asynchronous network messaging by implementing a back-and-forth binary messaging protocol on top of WebSocket.

Message responses themselves can also be requests, which differs from plain RPC protocols, in that it allows back-and-forth trampolining between server and client without having to manually track conversation states. Additionally, requests can also be made for streams, which allows for efficient list queries to be easily implemented. Stream responses can recursively be requests in themselves, and so forth.

Usage

import 'dart:io';
import 'package:wstalk/wstalk.dart';

runServer() async {
  HttpServer server = await HttpServer.bind('127.0.0.1', 9090);
  await for (HttpRequest request in server) {
    if (request.uri.path == '/ws') {
      // Upgrade to WSTalk socket
      WebSocket ws = await WebSocketTransformer.upgrade(request);
      TalkSocket ts = new TalkSocket(ws);
      // Register incoming message types
      ts.stream(42).listen((TalkMessage) {
        ts.close();
        server.close();
      });
      // Listen
      ts.listen();
    } else {
      // ...
    }
  }
  print("Server exited");
}

runClient() async {
  TalkSocket ts = await TalkSocket.connect("ws://localhost:9090/ws");
  testClient(ts);
  await ts.listen();
  print("Client exited");
}

testClient(TalkSocket ts) async {
  // Ping three times
  for (int i = 0; i < 3; ++i) {
    print(await ts.ping());
  }
  // Multi-ping three times
  for (int i = 0; i < 3; ++i) {
    // Receive four responses for each
    await for (int dt in ts.multiPing()) {
      print(dt);
    }
  }
  // Tell the server to close
  ts.sendMessage(42, new List<int>());
}

main() {
  runServer();
  runClient(); 
}