simple TCP chat node.js

Question

I am being new to node.js , coming from js background i have quite harder time to understand concept behind back end stuff, currently i am trying to create simple console chat. Code for server :

var net=require("net");
var sockets=[];
net.createServer(function(socket){
    sockets.push(socket);

    socket.on("data",function(data){
        posliSpravu(socket,JSON.parse(data));
    });

    socket.on("close",function(){
        console.log(socket + " has disconnected");
        sockets.splice(sockets.indexOf(socket),1);
    })

}).listen(8888);

function posliSpravu(from,message){
    var msg=JSON.stringify("Niekto povedal : " + message)+'\n';
    sockets.forEach(function(incoming_socket){
        if(incoming_socket!=from){
            incoming_socket.write(msg);
        }
    })
}

code for client

var net=require("net");
var client=new net.Socket();
client.connect(8888,function(){
    console.log("Connected");
});
process.stdin.resume();
process.stdin.on("data",function(data){
    posli(data);
})
client.on("data",function(data){
    console.log("Recieved data === " + JSON.parse(data));
})



function posli(msg){
    client.write(JSON.stringify(msg)+'\n');
}

When i am trying to send some message , it always outputs "Message recieved === [Object][Object]"

I tried to replace JSON.parse with JSON.strngify , but output was only some numer , propably test represented in ascii.

How can i fix it so it would display text i send<

"Message recieved === [Object][Object]" means you're trying to print objects as strings or that you attempted to send an object over the wire without stringifying it first. Try just printing the objects by themselves (not preceded by "Message received") and see what happens. — Mike Cluck
– Mike Cluck, Commented Jan 28, 2016 at 23:11
if no answer is given untill i wake up, i'll tell you a little about buffers in node, how they work and whats causing the trouble you ran into. — GottZ
– GottZ, Commented Jan 28, 2016 at 23:28
This is probably unrelated to your current issue, but you should know that you should not assume that each 'data' event will contain a complete JSON message. 'data' events can contain any number of bytes, so you could get half of a message in one event and the other half in the next. There are many ways to solve this (some more efficient than others). An easy solution is to use something like the built-in readline module with newline-terminated JSON strings/payloads. — mscdex
– mscdex, Commented Jan 28, 2016 at 23:30

GottZ · Accepted Answer · 2016-01-29 13:42:58Z

1

socket.setEncoding('utf8'); and process.stdin.setEncoding('utf8'); is your friend. you just need to add it once before the line you wait for data and everything should work as you thought about it initially.

answered Jan 29, 2016 at 13:42

GottZ

4,9771 gold badge39 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Johnyb Over a year ago

great! thanks , i now recieve message but with \r\n at the end , is there any way how to prevent this or is the only way to regExp it?

GottZ Over a year ago

\r\n is there for a reason. your process.stdin is reading line buffered. this is causing the stdin to fire data only as soon as you press return. return is btw equal to \r\n

GottZ Over a year ago

you could simply remove it by using something like regex: msg = msg.replace(/\r\n$/, ""); this will strip away \r\n at the end of a string (if it actually is found) if its not found the output is the same as the input.

Maroshii · Accepted Answer · 2016-01-28 23:27:18Z

0

You are calling JSON.stringify on a string. Make sure you use a valid object. Also better to send actual JSON over the wire:

//server
var msg=JSON.stringify({ name: 'Niekto povedal', content: message });

// client
var message = JSON.parse(data);
console.log("Recieved data from :" + message.name);
console.log("Recieved data === " + JSON.stringify(message.content));

answered Jan 28, 2016 at 23:27

Maroshii

4,0274 gold badges26 silver badges29 bronze badges

1 Comment

Johnyb Over a year ago

Recieved data from :Niekto povedal Recieved data === {"type":"Buffer","data":[97,104,111,106,13,10]} This is what i get , still ASCII codes for characters .

Collectives™ on Stack Overflow

simple TCP chat node.js

2 Answers 2

3 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related