Develop Reference

Socket.io middlewhere functions

I am trying to seperate logic in my socket.io server but i am experiance some issues.
say for instance i have the following:
io.on('connection', function (socket) {
var fileModule = require('./costum_modules/FileModule.js')(io);
app.use(fileModule);
});
Now inside the fileModule i have the following code:
var fileModule = function (socket) {
socket.on('userData', function(msg){
var i = 0;
});
}
module.exports = new fileModule();
Sadly the socket i undefined.
My question is can i do it like this or is it not possible to pass a singleton to another file and make it read from the same object?

You can use other files to break up your logic, but there are a couple issues with your code.
First, I think Hacketo is correct that you don't want to do new fileModule(), just:
module.exports = fileModule;
Second, when call require, you are passing the global socketIO object (io). You should pass it the socket you get in the connection handler. E.g.
require('./costum_modules/FileModule.js')(socket);
I think that will work to move some of your socket.io message handling code into a module. Now your socket will respond to userData messages from a client. However, unless you have some custom application, I don't think app.use is going to do what you expect. You can't hook web socket handlers into an Express/Restify/Connect/Whatever middleware chain. But you could write a middleware that sends a message to your socket server.
If you are just trying to share the session between your app and socket server, try this SO answer.

any way to send a function with socket.io?

guys.
I want to send a function to browser with socket.io, but failed to do it.
On server side, I response a function with emit, but I get a undefined on browser.
Is there any way to get a function from server with socketio?
there is my code.
// server.js
var static = require('node-static');
var http = require('http');
var file = new(static.Server)();
var app = http.createServer(function(req, res) {
file.serve(req, res);
}).listen(8000);
io = require('socket.io').listen(app);
io.sockets.on('connection', function(socket) {
socket.on('schedule', function() {
console.log('SCHEDULE TASK');
socket.emit('schedule', function() { console.log('hello world'); });
});
});
// client.js
var socket = io.connect('http://localhost:8000');
socket.on('schedule', function(fn) {
fn();
});
socket.emit('schedule');

You cannot send an actual function. You could send a string of Javascript and then you could turn that into a function in the client.
But, I'd suggest you really ought to rethink what you're trying to do here. Generally, the client already has the code it needs (from the script tags that it downloaded) and you send the client data which it then passes to the code it already has or data that it uses to make decisions about which code that it already has to call.
If you show us the real world problem you're trying to solve, we can likely suggest a much better solution than sending a string of Javascript code to the client.
If you really wanted to send a function, you would have to turn it into a string first, send the string, then use the string to turn it back into a function in the client by using a Function object or eval() or creating your own dynamic script tag with inline source.

You can only send strings via socket.io, not functions. That being said, I suggest you to send function names instead.
//server.js
socket.emit('schedule', 'helloworld');
//client.js
function helloworld(){
console.log('hello world');
}
socket.on('schedule',function(name){
window[name](); //hello world
});

Socket IO 1.2 Query Parameters

I can't figure out how to retrieve query parameters on the server side for socket.io
1.2.1
Here's my client side code
var socket = io('http://localhost:3000/',{_query:"sid=" + $('#sid').attr('data-sid') + "&serial=" + $('#serial_tracker').text()});
and the server side:
io.use(function(socket,next){ //find out if user is logged in
var handshake = socket.request;
console.log(socket.request._query);
handshake.sid = handshake.query.sid;
}
socket.request._query is:
{ EIO: '3', transport: 'polling', t: '1419909065555-0' }
Does anyone know how query parameters work in socket io 1.2.1?
Thanks for any help and if you need any more information, just ask me.

When sending handshake query data to socket.io, use the following property name in the object:
{
query: 'token=12345'
}
I see above you used _query for a property name instead.
You should be able to access the query information at socket.request._query at that point. I'm not sure if there is a better way to get a hold of that data? I'm guessing yes, since they put an underscore in front of it, but I haven't found a better way yet.
Here's the full example of a connect query that is working for me (forgive the formatting, I'm copy/pasting this out of different node modules into an inline solution).
Server (using socket 1.2.1 nodejs):
var restify = require('restify');
var api = restify.createServer();
var socketio = require('socket.io');
var io = socketio.listen(api.server); // api is an instance of restify, listening on localhost:3000
io.use(function(socket, next) {
// socket.request._query.token is accessible here, for me, and will be '12345'
next();
});
api.listen(3000, function() {
console.log('%s listening at %s', api.name, api.url);
});
Client (chrome browser using the client library located at https://cdn.socket.io/socket.io-1.2.1.js):
var socket = io.connect('http://localhost:3000/', { query: 'token=12345' });

ldapjs authentification (user login setup)

So I'm currently running node.js, which has ldapjs installed. My aim is to have a system that uses ldapjs to allow users to login with a username and password.
I have been reading over the http://ldapjs.org documentation for awhile now but am struggling to understand the whole idea of ldap and ldapjs's implementation of it.
I currently have this from the documentation
var ldap = require('ldapjs');
var server = ldap.createServer();
server.bind('cn=root', function(req, res, next) {
if (req.dn.toString() !== 'cn=root' || req.credentials !== 'secret')
return next(new ldap.InvalidCredentialsError());
res.end();
return next();
});
server.listen(1389, function() {
console.log('LDAP server up at: %s', server.url);
});
Which allows me to run the below and successfully bind to the server.
ldapsearch -H ldap://localhost:1389 -x -D cn=root -w secret -LLL -b "o=myhost" objectclass=*
But I'm really unsure of where to go from here or even if this is the correct approach...
The ideal setup would be to have a range of users and passwords, and on a successful ldap connection confirm the details are correct and respond with a true, or false if the username/pass was incorrect.
Does anyone know of any good resources for finding out more about this, or better yet can suggest some basic client/server side code to give me an idea of where to go next!
Any replies would be really appreciated.
Many Thanks

I never used ldapjs, but based on what I just quickly read in its seemingly incomplete document, it can be used to implement an LDAP server or an LDAP client, which seems to be what you're trying to do (i.e., I'm assuming you want to authenticate users in your application against an existing LDAP server). Most of the examples in its document focus on creating an LDAP server that listens on a certain port and interacts with a back-end database. If you're not trying to put an LDAP-based interface between your back-end database or store of users and passwords, then you probably don't need the server API. If you already have an LDAP server running, then you will need to use its client API to do something like this:
1.Bind anonymously to the LDAP server that provides the directory services including the authentication services. It looks like you can just do this with:
var ldap = require('ldapjs');
var client = ldap.createClient({
url: 'ldap://my.ldap.server'
});
2.Search by the username (e.g., e-mail address) for the corresponding entry's DN
var opts = {
filter: '(mail=USERNAME)',
scope: 'sub'
};
client.search('ou=users,o=acme.com', opts, function(err, res) {
assert.ifError(err);
res.on('searchEntry', function(entry) {
console.log('entry: ' + JSON.stringify(entry.object));
});
res.on('searchReference', function(referral) {
console.log('referral: ' + referral.uris.join());
});
res.on('error', function(err) {
console.error('error: ' + err.message);
});
res.on('end', function(result) {
console.log('status: ' + result.status);
});
});
3.Grab the DN of the returned entry ( entry.object ). The documentation of this library doesn't talk much about how these objects can be used (e.g., what their methods, properties, etc. are). So, you will have to figure out how to actually get the DN or string representation of the DN of the entry you just retrieved from the directory server. [See the comment(s) below this answer]
4.Rebind to the server using that DN:
client.bind(DN_RETRIEVED, PASSWORD_USER_ENTERED, function(err) {
assert.ifError(err);
});
5.The result of the bind above is what you will need to use to determine whether or not the authentication was successful.
If you are trying to implement an LDAP server in front of your user/password data store for LDAP-based authentication, then you will need to follow their server examples. I personally think this is an overkill and could be problematic in terms of security.

Socket IO | How to get the client transport type on the serverside?

I need to know what transport method a client is using for some conditional statements on the nodeJS serverside.
Does anyone know how I can get that information? Is it held within the client object?

As of Socket.IO 1.0:
Client:
socket.on('connect', function() {
console.log(socket.io.engine.transport.name);
}
Server:
io.sockets.on('connection', function(socket) {
console.log(socket.conn.transport.name);
}

In socket.io 0.7.6
io.sockets.on('connection', function(client) {
console.log(io.transports[client.id].name);
});

April 2012, this works: socket.transport

I'm sure you can find it if you dig in the internals of a client object, although without knowing why you need this I have to recommend against this kind of check for 2 reasons:
Firstly, since it isn't in the API the developers have absolutely no responsibility to keep things backward compatible, so any given version might implement/store that information differently, which will only ripple into your own development and cause problems.
Secondly, and more importantly, I suggest you rethink your design, the communication with the server thru socket.io is built to be transparent to the method being used. There should be no difference on either side. That's the purpose of the library, designing an app that behaves otherwise is totally orthogonal to that idea.

for reference's sake and google stumbles:-
in case anyone is still using v0.9 (or possibly earlier)
you can access this info from client side like this:
var socket = io.connect();
console.log(socket.socket.transport.name); //log the name of the transport being used.
answer found on google groups https://groups.google.com/forum/#!topic/socket_io/yx_9wJiiAg0

I believe this will solve your problem. My trick here is to save the transport type on the HTTP Request object once the client connects. You can then pick it up in your callback later. First we tweak the Listener class:
var io = require('socket.io'),
io.Listener.prototype._onConnectionOld = io.Listener.prototype._onConnection;
io.Listener.prototype._onConnection = function(transport, req, res, up, head){
req.socketIOTransport = transport; // Take note of the transport type
this._onConnectionOld.call(this, transport, req, res, up, head);
};
And then below in the body of your app:
var socket = io.listen(app),
socket.on('connection', function(client){
console.log(client.request.socketIOTransport); // Lets check that transport
// ...
});
Hope this helps!

io.connect.managers['connect url/port'].engine.transport