socket.io middleware
http://socket.io/docs/server-api/#namespace#use(fn:function):namespace
Namespace#use(fn:Function):Namespace
Registers a middleware, which is a function that gets executed for
every incoming Socket
and receives as parameter the socket and a
function to optionally defer execution to the next registered
middleware.
var io = require('socket.io')();
io.use(function(socket, next){
if (socket.request.headers.cookie) return next();
next(new Error('Authentication error'));
});
Errors passed to middleware callbacks are sent as special error
packets to clients.