websocket_channel_wrapper

Description:

websocket channel wrapper

Wrapper for web_socket_channel package lightweight and isomorphic lib with socket.io-like event handling, Future-based requests. This wrapper implements the protocol for this ws node wrapper.
WARNING: server -> client requests are not sopported. If someone needs them open a PR
Usage #
A simple usage example:
Client side:
import 'dart:async';
import 'dart:io';
import 'package:websocket_channel_wrapper/websocket_channel_wrapper.dart';

const PORT = 42069;

main() {
WebSocketChannelWrapper socket = WebSocketChannelWrapper('ws://192.168.0.18:$PORT',
headers: {'id': '1234567890qwertyuiop'});

print('Connecting...');

var onReady = socket.onConnect.first;

onReady.timeout(Duration(seconds: 5), onTimeout: () => print('Server could not be reach, trying to re-connect'));

socket.onConnect.skip(1).listen((_) => print('Successful re-connection to server'));

socket.onDone.listen((_) => print(socket.autoReconnect ? 'Connection lost, trying to re-connect!' : 'Connection ended!'));

onReady.then((_) async { // [onConnect] It's called every time the WebSocket reconnect
print('Connected!');

socket.emit('msg', ['DART_WEBSOCKET_WRAPPER', 'Hello, World!']);

socket.on('serverTime').listen((time) => print('Time: $time')); // Time: 2019-07-29T14:00:32.635Z

socket.request('userCount').then((n) => print('# users: $n')); // # users: 1

socket.request('checkError').catchError((e) => print(e)); // Yep, errors work

var filename = '/path/to/file/image.jpg';
sendFile(filename, socket); // Send binary file over socket

Timer(Duration(seconds: 10), () { // Close the socket after 1 minute
var reason = 'break time';
print('Close reason: $reason');
socket.close(closeReason: reason);
});
});
}

sendFile(String filename, socket) async {
var image = File(filename);
var contents = await image.readAsBytes();

final stopwatch = Stopwatch()..start(); // Start timer to measure speed

socket.request('transferFile', [filename, contents]).then((_) { // Send first file name then the bytes

final speed = contents.length / stopwatch.elapsedMicroseconds;
print('File sended in ${stopwatch.elapsed} at $speed MB/s'); // File sended in 0:00:00.058191 at 1.63 MB/s

}).catchError((e) => print(e));
}


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Server side:
const WebSocketServer = require("ws").Server
, WebSocketWrapper = require("ws-wrapper")
const fs = require('fs')

const PORT = 42069

var wss = new WebSocketServer({port: PORT});
var sockets = new Set();

wss.on("connection", (sckt, req) => {
const socket = new WebSocketWrapper(sckt)
sockets.add(socket)

console.log('New socket connected')
socket.emit('serverTime', new Date()) // Send data to client on connect

socket.on("msg", function(from, msg) {
console.log(`Received message from ${from}: ${msg}`) // Received message from DART_WEBSOCKET_WRAPPER: Hello, World!
});

socket.on("userCount", () => { // Request
return sockets.size;
});

socket.on("checkError", () => { // Request rejecting the Promise
throw 'Yep, errors work'
})

socket.on("transferFile", (filename, buffer) => {
return new Promise((resolve, reject) => {
fs.writeFile(filename, Buffer.from(buffer), function(err) { // Save binary data recieved to file
if(err)
reject(err)
else{
resolve(true)
console.log('File received and saved!')
}
})
})
})

socket.on("disconnect", (event) => {
console.log(`REASON: ${event.reason} CODE: ${event.code}`) // REASON: break time CODE: 1007
sockets.delete(socket);
});
})

console.log('Listening on port: ' + PORT)
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