So, I am quite puzzled. I have a socket IO server that runs OK, and the HTML web client does connect to it. But, I can't emit anything. I'm using xampp to serve webpages, but does socket IO need to serve content for it to receive and send data? It's weird that I connect OK,but that's it, no emit function works.
Here's my code..
var io = require('socket.io')();
io.on('connection', function(client){ console.log("Connected OK."); io.emit('message',"data"); });
io.on('message', function(client){ console.log(client); });
io.listen(8080);
HTML
<script src="http://localhost:8080/socket.io/socket.io.js"></script>
<script>
// Create SocketIO instance, connect
var socket = io.connect('http://localhost:8080');
// Add a connect listener
socket.on('connect', function() {
alert('Client has connected to the server!');
});
socket.on('message', function(event) {
console.log('Received message from client!', event);
});
</script>
The code above prints "Connected OK" to the NPM console, and it alerts "Client has connected to the server!", but that's it. So my question is, does the NPM server need to serve the HTML to work, or am I doing things wrong?. I use xampp because of PHP and MySQL.
UPDATE:## The server sends to client just fine, and the client tries to send data back, and the server receives the packet. But then it reports: " engine:polling transport discarded - closing right away +0ms". Is this normal?
Related
I have a node.js server and I attached socket.io listener to it. The code is like this.
const server = new Hapi.Server();
server.connection({
"port": config.port
});
let io = socketio(server.listener);
io.on("connection", function(socket) {
console.log("A user connected");
socket.on("disconnect", function(){
console.log("A user disconnected");
});
// receive message from client
socket.on("client-server", function(msg) {
console.log(msg);
});
});
// somewhere to emit message
io.emit("server-client", "server to client message");
Normally I use the standard way to connect to the websocket server. An example is like this:
<!DOCTYPE html>
<html>
<head><title>Hello world</title></head>
<script src="http://localhost:3000/socket.io/socket.io.js"></script>
<script>
var socket = io();
socket.on('server-client', function(data) {document.write(data)});
socket.emit('client-server', 'test message');
</script>
<body>Hello world</body>
</html>
It works without issue. Now, my colleague wants to connect to the websocket server from his FME server. Based on his research, the only way he can use to connect to a websocket server is using a url like this:
ws://localhost:3000/websocket
My question is: is there a way to connect to socket.io server listener using this type of string?
If not, is there a way to create a websocket server with ws://host:port url and also attach it to my node.js server?
Or, is there a way to connect to socket.io listener in FME server?
To tell Socket.IO to use WebSocket only, add this on the server:
io.set('transports', ['websocket']);
And on the client add this:
var socket = io({transports: ['websocket']});
Now you can only connect to the WebSocket server using ws protocol.
I have a very basic setup with socket.io but am having trouble getting my server to send back a message once the connection has been established.
When a connection is established to my server, I want the server to send back a message to the client. I've tried to accomplish this with the following code:
Server
// Modules
var fs = require('fs');
var https = require('https');
// Certificate
var options = {
pfx: fs.readFileSync('<my cert>')
};
// Create Server
httpsServer = https.createServer(options);
// Create websocket
var io = require('socket.io')(httpsServer);
// Listen on a port
httpsServer.listen(4000,function() {
console.log('listening on *:4000');
});
io.on('connection', function(socket) {
console.log('a user connected');
socket.emit('test','you connected');
});
Client
var socket = io('https://<my server>:4000');
When I execute this code, the websocket gets established and my server console shows the message "a user connected". However, the message ['test','you connected'] does not get emitted through the socket.
The only way I've been able to get this to work is to use setTimeout() to wait 500ms before emitting the event, in which case it does work.
Why is that? How can I configure my server to automatically respond with a message as soon as the user connects?
You need to listen to the emitted event, using socket.on(event, callback);
<script src="https://cdn.socket.io/socket.io-1.4.5.js"></script>
<script>
var socket = io('https://localhost:4000');
//test is the emitted event.
socket.on("test", function(data){
console.log(data); //"you connected"
});
</script>
I've been trying to do basic communication between an app and my server but no matter what I do I can't seem to get it to work.
Below is my js code
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
io.on('connection', function(socket){
console.log('a user connected');
io.emit("hello");
socket.on('disconnect', function() {
console.log('a user disconnected');
});
socket.on('response', function(message){
console.log(message);
});
});
http.listen(3000, function(){
console.log('listening on *:3000');
});
This should in theory be alerted when a user connects, output a message saying the user has connected and then emit an event "hello"
below the on disconnect part I am trying to communicate with the server from my iOS app. I emit a event called "response" with a string called "I got your response".
I get the "a user connected" message in the console but the message I send from the iOS app never gets printed in the console.
This the code in my app.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
let socket = SocketIOClient(socketURL: "192.168.0.3:3000")
socket.on("hello") {data, ack in
socket.emit("response", "I got your response")
}
socket.connect()
}
As you can see my server side code emits the event "hello". This should trigger the socket.on("hello") and make the app emit the event "response" which makes the server print out the string sent with it.
None of this is happening apart from the message that gets printed in the console when a user connects.
An help would be greatly appreciated.
the Github repo for the framework is below
https://github.com/socketio/socket.io-client-swift
Declare and initiate your socket variable in the top of the class. As previous comments said, I think the variable is lost in the scope otherwise.
class HostSocketHandler {
let socket = SocketIOClient(socketURL: urlString)
init(){
socket.connect();
}
}
I'm trying to test out Node.js and I'm using this code:
// Load the net, and sys modules to create a tcp server.
var net = require('net');
var sys = require('sys');
// Setup a tcp server
var server = net.createServer(function (socket) {
// Every time someone connects, tell them hello and then close the connection.
socket.addListener("connect", function () {
//sys.puts("Connection from " + socket.remoteAddress);
console.log("Person connected.");
var myPacket = [1,2,3,4,5];
sys.puts(myPacket);
socket.end("Hello World\n");
});
});
// Fire up the server bound to port 7000 on localhost
server.listen(7000, "localhost");
// Put a friendly message on the terminal
console.log("TCP server listening on port 7000 at localhost.");
To send a byte array to any connections that show up on port 7000 of local host. Nothing is connecting though, I've tried firefox (localhost:7000, and 127.0.0.1:7000) I tried PuTTy, and even writing my own Java TCP Client to connect to local host, but nothing is working, so I'm convinced that the code is wrong.
Can someone please tell me why my code won't allow connections?
You seem to be overcomplicating the connection part. The callback with the socket is already the connection event so you don't need to listen to it separately. Also, if you want to send binary, use the Buffer class. Here's your code changed. Remember to set your mode to telnet in putty when connecting. I've also changed the end() to write() so it doesn't auto close the connection.
// Load the net, and sys modules to create a tcp server.
var net = require('net');
var sys = require('sys');
// Setup a tcp server
var server = net.createServer(function (socket) {
//sys.puts("Connection from " + socket.remoteAddress);
console.log("Person connected.");
var myPacket = new Buffer([65,66,67,68]);
socket.write(myPacket);
socket.write("Hello World\n");
});
// Fire up the server bound to port 7000 on localhost
server.listen(7000, "localhost");
// Put a friendly message on the terminal
console.log("TCP server listening on port 7000 at localhost.");
I have a socket.io connection to connect to server and client,
It work fine.
Now when I try to reconnect it on disconnect from server it get connected but then socket.on('message' doesnt get fired any more.
I checked it from server side it is pushing that message.
Please suggest me some thing I am out of ideas now.
I am sure that problem is on client side socket.on message
Client side code
var socket = new io.Socket('some host name',{port:80,rememberTransport:true});
socket.on('connect', function(){
clearInterval(socketInterval);
});
socket.on('message', function(obj)
{
alert("meg from server");
});
socket.on('disconnect', function()
{
socketInterval=setInterval("socket.connect()",5000);
});
socket.connect();
I don't know node.js, but it looks like syntax error, haven't you forgot the right paratheses?
socket.on('connect', function(){
clearInterval(socketInterval);
});
socket.on('message', function(obj)
{
alert("meg from server");
});
socket.on('disconnect', function()
{
socketInterval=setInterval("socket.connect()",5000);
});
it would appear that the "problem" most likely is on the server side. The server has two ways to send messages to the client (emit and broadcast). If you are doing a one to one message, most people use emit. I am assuming that you built a chat server which stores the sessionIds of the client. It works fine with the initial connection because the server has the correct sessionId, but let's say connection is lost and you reestablish connection, now the server tries to send a message to the client. If your server stored the initial sessionId, say in an array, and attempts to use the original sessionId to emit a message, it will fail because reconnection causes a new sessionId to be created.
The solution in this case is to remove the previous sessionId from the array and add the new sessionId upon reconnection.