parameter callback is null/undefined

Hi all, for some reason I’m trying to translate licode client into C++, but when I send ‘publish’ signal to licode server, what confuses me is that how the parameter callback is null/undefined,

socket.on(‘publish’, function (options, sdp, callback) {
var id, st;
if (socket.user === undefined || !socket.user.permissions[Permission.PUBLISH]) {
// callback(null, ‘Unauthorized’); // [NODE]: licode server crashed in here


I‘m stranged to node.js, can anyone tell me what the matter.i…

are you trying to run the basic example or is this your own implementation, can you share more info on what you are doing ?