Socket.IO only emitting to all clients

Question

Right part of my code is

io.sockets.on('connection', function(socket){
var interval = setInterval(function() {
    repaintGraph()
    socket.emit('set data chart', '{"series":[['+series+']]}');
}, 1000 );

The chart in this case, if I have 3 users connected, the chart updates 3 times in one second I need to execute the code 1 time in 1 second, regardless of the number of clients

Answer 1

You can run the interval code outside of the connection code:

setInterval(function() {
  repaintGraph();
  io.emit('set data chart', '{"series":[['+series+']]}');
}, 1000);

io.on('connection', function() {
  ...
});

io.emit() will broadcast the message to all connected clients, every second.

There's a little bit of an inefficiency in the code, in that it will call repaintGraph() every second even if there aren't any clients connected, but it makes the code much easier.