[javascript] how to get session id of socket.io client in Client

* Please Note: as of v0.9 the set and get API has been deprecated *

The following code should only be used for version socket.io < 0.9
See: http://socket.io/docs/migrating-from-0-9/



It can be done through the handshake/authorization mechanism.

var cookie = require('cookie');
io.set('authorization', function (data, accept) {
    // check if there's a cookie header
    if (data.headers.cookie) {
        // if there is, parse the cookie
        data.cookie = cookie.parse(data.headers.cookie);
        // note that you will need to use the same key to grad the
        // session id, as you specified in the Express setup.
        data.sessionID = data.cookie['express.sid'];
    } else {
       // if there isn't, turn down the connection with a message
       // and leave the function.
       return accept('No cookie transmitted.', false);
    }
    // accept the incoming connection
    accept(null, true);
});

All the attributes, that are assigned to the data object are now accessible through the handshake attribute of the socket.io connection object.

io.sockets.on('connection', function (socket) {
    console.log('sessionID ' + socket.handshake.sessionID);
});