Is it possible to create a tcp client with electron - electron

Question

Is it possible to create a tcp client with electron?
Or can we access the chrome socket api with does that?
https://developer.chrome.com/apps/sockets_tcp

Answer 1

You can use the Node net API in Electron to implement a TCP client.
Try this sample code (don't forget to change IP address) with a little socket server as SocketTest java application for example (HERE).
At the connection, you should see a "World!" string on server side. Try to send this message from server:
{
"nom":"Xplorer",
"prenom":"Yann"
}
And you should see Hello Yann! in your electron console.
'use strict';
const electron = require('electron');
const path = require('path');
const url = require('url');
const net = require('net');
const app = electron.app;
const BrowserWindow = electron.BrowserWindow;
let mainWindow;
var socketClient
function createWindow () {
// Create the browser window.
mainWindow = new BrowserWindow({width: 800, height: 600,backgroundColor:'#FFFFFF', frame:false})
// and load the index.html of the app.
mainWindow.loadURL(url.format({
pathname: path.join(__dirname+'/html/', 'main.html'),
protocol: 'file:',
slashes: true
}))
// Open the DevTools.
//mainWindow.webContents.openDevTools()
// Emitted when the window is closed.
mainWindow.on('closed', function () {
// Dereference the window object, usually you would store windows
// in an array if your app supports multi windows, this is the time
// when you should delete the corresponding element.
mainWindow = null
})
/* Instance socket on create window */
console.log('Try to connect');
socketClient = net.connect({host:'192.16.122.3', port:9042}, () => {
// 'connect' listener
console.log('connected to server!');
socketClient.write('world!\r\n');
});
socketClient.on('data', (data) => {
console.log(data.toString());
var person = JSON.parse(data);
console.log('Hello '+person.prenom+"!");
});
socketClient.on('end', () => {
console.log('disconnected from server');
});
//mainWindow.openDevTools();
}
app.on('before-quit',function(){
socketClient.end();
})
see you.

Answer 2

You can use the Node net API in Electron to implement a TCP client.

Answer 3

It's easy to just test if the chrome API is present. If not I use the node API. So that I have the same code base for my Chrome App and my Electron App.
The 2 APIs are slightly different so I post here how to do it.
let client = null; // node socket
let socketId; // chrome API socket id
function toBuffer(ab) {
return new Buffer(new Uint8Array(ab));
}
function toArrayBuffer(buf) {
return new Uint8Array(buf).buffer;
}
function initConnToServer (ip, port) {
return new Promise((resolve, reject) => {
if(typeof chrome !== 'undefined') {
chrome.sockets.tcp.create({}, r => {
socketId = r.socketId;
chrome.sockets.tcp.connect(r.socketId, ip, port, code => resolve(code));
});
} else {
client = new net.Socket(); // return a Node socket
client.connect(port, ip);
client.on('connect', () => resolve());
}
});
};
function sendToServer_simple (data) {
return new Promise((resolve, reject) => {
if(typeof chrome !== 'undefined') {
chrome.sockets.tcp.send(socketId, data, r => {});
chrome.sockets.tcp.onReceive.addListener(receiveInfo => resolve(receiveInfo.data));
} else {
client.write(toBuffer(data));
client.on('data', data => resolve(toArrayBuffer(data)));
}
});
};