I followed the net tuts tutorial to build a simple chat application with socket and node, and now I'm trying to extend the app to allow people to play a game I've written, so I want to let people list the games available, but I can't seem to pass even a simple test array from server to client.

I'll let the code speak for itself:

Relevant Server Code:

var games = ["test"];
io.sockets.on('connection', function (socket) {
  socket.emit('message', { message: 'wele to the chat' });
  socket.on('gameList', function (data) {
    io.sockets.emit("games",games);
  });
  socket.on('send', function (data) {
    io.sockets.emit('message', data);
  });
});

ClientSide:

window.games = [];
$("#listGames").click(function(){
  socket.emit("gameList", function(data){
    window.games = data;
  })
})

So I console.log games before and after the button click, and it's always just an empty array, when in my head, it should contain the string "test".

So where did I go wrong?

Note: Added jQuery to the codebase even though the tutorial missed it.

I followed the net tuts tutorial to build a simple chat application with socket and node, and now I'm trying to extend the app to allow people to play a game I've written, so I want to let people list the games available, but I can't seem to pass even a simple test array from server to client.

I'll let the code speak for itself:

Relevant Server Code:

var games = ["test"];
io.sockets.on('connection', function (socket) {
  socket.emit('message', { message: 'wele to the chat' });
  socket.on('gameList', function (data) {
    io.sockets.emit("games",games);
  });
  socket.on('send', function (data) {
    io.sockets.emit('message', data);
  });
});

ClientSide:

window.games = [];
$("#listGames").click(function(){
  socket.emit("gameList", function(data){
    window.games = data;
  })
})

So I console.log games before and after the button click, and it's always just an empty array, when in my head, it should contain the string "test".

So where did I go wrong?

Note: Added jQuery to the codebase even though the tutorial missed it.

• javascript
• node.js
• socket.io

1 Answer 1

You are using socket.emit() to attempt to receive data. That only sends data to the server. You need a games event handler on your client to handle the event accordingly.

window.games = [];

$("#listGames").click(function() {
  socket.emit('gameList');
});

socket.on('games', function (games) {
  window.games = games;
});

The event handler for games is what will fire when you execute io.sockets.emit('games', games); on the server side.

Also make sure to always pass an object as the response over Socket.IO. Change the server-side code from : var games=[]; to var games={'games':[]}; or something similar.