Question

Is it possible to run some script and if client connected pass arguments to it, something like this:

 var io = require('socket.io').listen(http);
 io.sockets.on('connection', function (client) {
     console.log('Client connected');
     var notifikacija = function (array) {
         client.emit('populate', array);
     }
 });

 ///////////////////////////////////////////////////////////////////////

 setInterval(function(){
     var array = newArray();
     array[0]='test';
     notifikacija(array);
 }, 2000);

Now it shows error: notifikacija is not defined. It is quite a strugle…

Answer 1

The notifikacija function is local to the scope of the io.sockets.on handler. You want it to be global so that you can access it in setInterval:

var notifikacija = function(){}; // just an empty function, in case it gets called before it has something to do
var io = require('socket.io').listen(http);
io.sockets.on('connection', function(client) {
     console.log('Client connected');
     notifikacija = function(array){ // once the client is available assign the function
         client.emit('populate', array);
     }  
});

setInterval(function(){
    var array = newArray();
    array[0]='test';
    notifikacija(array);
}, 2000);

Here’s a blog post with some more information on scope in Javascript.