Hey uh I am having an issue and I think this is probably related to net.createserver.
The issue is that whenever the first client joins after that another second client joins, the first client can control the second client and then the first client disconnects because the socket(end) event gets triggered. Is it related to sockets or something or the server can't handle two connections? Please help
The code:
handleGame: function() {
console.log(log.success('The source is starting!'));
var server = net.createServer(function(socket) {
console.log('A client has connected' + "\r\n");
socket.setEncoding('utf8')
global.clientObjz = new client(socket);
game.addClient(clientObjz);
socket.on('data', function(data) {
data = data.toString().split('\0')[0];
console.log('Incoming data: ' + data + "\r\n")
if (data == "<msg t='sys'><body action='verChk' r='0'><ver v='153' /></body></msg>" | data == "<msg t='sys'><body action='rndK' r='-1'></body></msg>" | data.startsWith("<msg t='sys'><body action='login' r='0'>")) {
parseXml(data, function(err, result) {
var type = result.msg['$'].t,
action = result.msg.body[0]['$'].action;
var method = Game.xmlHandlers[type][action];
if (typeof Game[method] == 'function') {
Game[method](data, client);
}
});
}
var dataType = data.charAt(0);
if (dataType == '%') {
game.handleraw(data, clientObjz);
}
});
socket.on('end', function() {
game.removeClient(socket);
console.log('A client has disconnected');
});
socket.on('error', function(err) {
console.log(err);
});
});
server.listen(Game1, "localhost", function() {
console.log('Server is listening on port 6113');
});
}
//this code is another file as i am calling it by game.clients.push
addClient: function(client) {
if (client) {
self.clients.push(client);
}
}
Yes, it's a clubpenguin emulator
full code: https://github.com/dev3211/bingojs
You need to implement socket channels if you are doing this only with NodeJS net.createServer. If you want it simple, you could look for something using express.js, something like this: https://medium.com/factory-mind/websocket-node-js-express-step-by-step-using-typescript-725114ad5fe4
Related
I am very beginner in NodeJS, I am taking data from S71200 PLC device using nodes7 library, I want to pass data using socket io emit but I can't pass data to socket io emit below my code
app.js
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var nodes7 = require('nodes7'); // This is the package name, if the repository is cloned you may need to require 'nodeS7' with uppercase S
var conn = new nodes7;
var doneReading = false;
var doneWriting = false;
var variables = {
TEST7: 'DB1,INT2.3',
TEST1: 'DB1,X0.0.3',
TEST2: 'DB1,INT2'
};
conn.initiateConnection({port: 102, host: '127.0.0.1', rack: 0, slot: 1}, connected);
function connected(err) {
if (typeof(err) !== "undefined") {
// We have an error. Maybe the PLC is not reachable.
console.log(err);
process.exit();
}
conn.setTranslationCB(function(tag) {return variables[tag];}); // This sets the "translation" to allow us to work with object names
conn.addItems(['TEST7','TEST1']);
//conn.writeItems('TEST2', 90, valuesWritten);
setInterval(function(){
conn.readAllItems(valuesReady);
},1000)
}
function valuesReady(anythingBad, values) {
if (anythingBad) { console.log("SOMETHING WENT WRONG READING VALUES!!!!"); }
console.log(values.TEST1[0],values.TEST1[1],values.TEST1[2],values.TEST7[0],values.TEST7[1],values.TEST7[2]);
//console.log( typeof(temp));
doneReading = true;
}
function valuesWritten(anythingBad) {
if (anythingBad) { console.log("SOMETHING WENT WRONG WRITING VALUES!!!!"); }
console.log("Done writing.");
doneWriting = true;
}
io.on('connection',function(socket){
console.log('one user connected '+socket.id);
socket.emit("channelname", {
message: "Passing S71200 data"
});
socket.on('disconnect',function(){
console.log('one user disconnected '+socket.id);
});
})
http.listen(3000,function(){
console.log('server listening on port 3000');
})
I am using interval function because every second data fetch from PLC device, I got all data from values.TEST1[0],values.TEST1[1],values.TEST1[2],values.TEST7[0],values.TEST7[1],values.TEST7[2] this data passing to
io.on('connection',function(socket){
console.log('one user connected '+socket.id);
socket.emit("channelname", {
message: "Passing S71200 data"
});
socket.on('disconnect',function(){
console.log('one user disconnected '+socket.id);
});
})
Help me to solve this problem
I'm totally new to the whole nodeJS asynchronous-y callback-y programming so I need more like a guidance to understanding what I'm even doing. With that said, I have two files main.js and server.js
My main file looks like this:
var server=require('./server.js');
server();
function WhenUserClicksButton(){
server();
}
and my server file looks like this:
var net = require('net');
function server(){
net.createServer(function (socket) {
socket.write('\x16'); //SYN character
socket.on('data', function (data) {
//handle data from client
});
}).listen(33333);
}
First call of server(); starts the TCP server. Then function WhenUserClicksButton is called when user clicks button (duhh) in a GUI. But it attempts to start the server again so I get
Error: listen EADDRINUSE :::33333
I got why this is happening but I can't think of a solution for it. What I really need is:
Start the server and listen on 33333
When nothing is happening server and client just exchanges SYN and ACK characters every few seconds (I already have this part done, I just removed it from this example for clarity because it's not really topic of this question)
When user click button change socket.write('\x16'); to socket.write('something');
Then wait for server and client to exchange data and after everything is done return results back to main.js
As I said, I'm new to this and I believe my problem lies in not understanding fully of what I'm doing. Any help and explanations are welcome!
I think you're very near where you need to be. I would do something like this:
server.js
var net = require('net');
var netServer = null;
var netSocket = null;
function sendData(data) {
if (netServer && netSocket) {
console.log('Send data: sending: ', data);
netSocket.write(data);
}
}
function startServer(){
netServer = net.createServer(function (socket) {
netSocket = socket;
socket.write('\x16'); //SYN character
socket.on('data', function (data) {
console.log('Server: data from client: ', data);
if (data.length === 1 && data[0] === 0x16) {
// log and ignore SYN chars..
console.log('SYN received from client');
} else if (newDataCallback) {
newDataCallback(data);
};
});
});
console.log('Server listening on 33333..');
netServer.listen(33333);
}
var newDataCallback = null;
function setNewDataCallback(callback) {
newDataCallback = callback;
}
module.exports = {
sendData: sendData,
startServer: startServer,
setNewDataCallback: setNewDataCallback
};
main.js
var server = require('./server');
function newDataCallback(data) {
console.log('newDataCallback: New data from server: ', data);
}
server.setNewDataCallback(newDataCallback);
server.startServer();
function wheneverUserClicksButton() {
server.sendData('something');
}
testClient.js
var clientSocket = net.createConnection(33333, "127.0.0.1");
clientSocket.on('data', (someData) => {
console.log('Data received', someData);
});
clientSocket.on('connect', () => {
console.log('Client Socket connected ');
clientSocket.write('Hello from client');
});
I have two applications A and B in Node Js and application B wants to communicate with application A.
Now Application A selects its port dynamically during run time. So how Application B can discover on which Port application A is running?
You can handle an event in app A and app B for ECONNREFUSED before starting your server in express which will take care of the port in used.if you see this error then just change the port number dynamically which will be true for both apps.
I did some more research and came up with solution which is "dns-discovery" and "openport"
First Check which port is open in your system using "openport" and then use "dns-discoverry".
Application A
var op = require('openport');
op.find(
{
startingPort: 8050,
endingPort: 8999
},
function (err, port) {
if (err) { console.log(err); return; }
console.log('opened port is:::::::::' + port);
ServerStart(port);
}
);
function ServerStart(port) {
var discovery = require('dns-discovery');
var disc = discovery();
disc.announce('connect-apps', port, function () {
console.log("announcement start")
});
var io = require('socket.io')(port);
io.on('connection', function (socket) {
socket.on('message', function (msg) {
console.log("Response From Client::::::::::::" + msg);
socket.send("Congratulations from Server");
});
socket.on('disconnect', function (msg) {
console.log("We are disconnected");
});
})
}
Application B
var discovery = require('dns-discovery')
var disc = discovery()
disc.lookup('connect-apps', function () {
console.log('Server Lookup Started:::::::::::::::::::')
})
disc.on('peer', function (name, peer) {
console.log("Server found:::::::::" + peer.host + ':::' + peer.port);
var ws = 'ws://' + peer.host + ':' + peer.port;
var socket = require('socket.io-client')(ws, { forceNew: true });
socket.io.opts.transports = ['polling', 'websocket'];
socket.on('connect', function () {
console.log('connected');
socket.send('Hello from Client 1::::::::Vishal Shori Machine');
});
socket.on('message', function (msg) {
console.log("response again::::::::::::" + msg);
});
disc.destroy();
})
For Reference :
https://www.npmjs.com/package/openport
https://github.com/mafintosh/dns-discovery
I am new with the node js.
I am using node js with express.
I am create connection on server side via below code.
io.sockets.on('connection', function (socket) {
// console.log('A new socket connected with id : '+socket.id);
socket.on('error',function(e){
// console.log(e);
})
socket.on('disconnect',function(e){
// console.log( " \n disconnect \n ",e);
})
socket.on('UserRoom', function(data){
var user_id = data.user_id;
if(socket.adapter.rooms[user_id]===undefined)
{
console.log('Hey i am connected to server for User id => '+user_id);
socket.join(user_id);
}
else
{
console.log('Hey i am already connected to User id');
}
});
socket.on('JoinDraft', function(data)
{
var game_unique_id = data.game_unique_id;
socket.join(game_unique_id);
});
});
app.post('/game_update', function(req, res)
{
var target = true;
var response = '';
req.on('data', function (data) {
response += data;
});
req.on('end', function () {
res.sendStatus(200);
var result = JSON.parse(response);
game_update(result);
});
});
function game_update( result )
{
var game_unique_id = result ;
io.to(game_unique_id).emit('game_update', {"game_unique_id": game_unique_id});
};
client side code :- for joining room
function joinDraft_socket() {
// console.log(gameObj);
socket.emit('JoinDraft',{"game_unique_id" : gameObj.game_unique_id});
}
for getting node response , we have
socket.on('game_update', function(data) {
if(data.game_unique_id == gameObj.game_unique_id) {
console.log('Trigger to update ', data);
isYourPick();
}
});
Server node emit data single time to any room ( game_unique_id) then clients are receiving server ping multiple times.
Please let me know if any one face this kind of issue and how they resolved it.
Below is image of console after single update of server node , client receive multiple hits
Any help is appreciate ...
Thanks in Advance
I have the following example of listening to connection and data events, to echo the result back to other telnet clients listening on port 8888. My telnet sessions connect to locahost fine, but no output is echoed. I am hitting my head against a brick wall trying to figure out what is wrong. The execution doesn't even get as far as the 'connect' event.
/server.js
var events = require('events');
var net = require('net');
var channel = new events.EventEmitter();
channel.clients = {};
channel.subscriptions = {};
channel.on('join', function (id, client) {
this.clients[id] = client;
this.subscriptions[id] = function (senderId, message) {
if (id != senderId) {
this.clients[id].write(message);
}
}
this.on('broadcast', this.subscriptions[id]);
});
var server = net.createServer(function (client) {
var id = client.remoteAddress + ':' + client.remotePort;
console.log(id);
client.on('connect', function () {
console.log('A new connection was made');
channel.emit('join', id, client);
});
client.on('data', function (data) {
data = data.toString();
channel.emit('broadcast', id, data);
});
});
server.listen(8888);
I then run in the command line
node server.js
telnet 127.0.0.1 8888
When the callback to net.createServer is called, that's because of an implicit connection event. So your code should look like this:
var server = net.createServer(function (client) {
// when this code is run, the connection has been established
var id = client.remoteAddress + ':' + client.remotePort;
console.log('A new connection was made:', id);
channel.emit('join', id, client);
client.on('data', function(data) {
...
});
client.on('end', function() {
...
});
});
The manual has this to say;
net.createServer([options], [connectionListener])
Creates a new TCP server. The connectionListener argument is automatically set as a listener for the 'connection' event.
In other words, your function (client) { already received the connection event, and adding a listener to it when it has already been dispatched has no further effect.