How to access express.session.MemoryStore via socket.io objects? - node.js

Question

I am doing this in a login function
app.post('/teacherlogin', function(request, response) {
var username = request.body.username;
var password = request.body.password;
con.query('SELECT t_id from login_teacher where username="'+username+'" and password="'+password+'"',function(err,results){
if(results.length > 0) {
request.session.regenerate(function(){
request.session.user = username;
request.session.type = 'teacher';
request.session.id = results[0].t_id;
response.redirect('/teacherhome');
});
} else {
response.redirect('teacherlogin');
}
});
});
now I want to emit the 'id' and 'type' I have stored to the session object. How should I do this? I have read this article but being inexperienced I am facing difficulty in using it. I have used it in my code
var MemoryStore = express.session.MemoryStore;
var sessionStore = new MemoryStore();
app.use(express.bodyParser());
app.use(express.cookieParser('secret text'));
app.use(express.session({
store: sessionStore,
secret: 'secret',
key: 'express.sid'}
));
and
var Session = require('connect').middleware.session.Session;
io.set('authorization', function (data, accept) {
if (data.headers.cookie) {
data.cookie = require('cookie').parse(data.headers.cookie);
data.sessionID = data.cookie['express.sid'].split('.')[0];
console.log('data.sessionID "'+data.sessionID);
data.sessionStore = sessionStore;
sessionStore.get(data.sessionID, function (err, session) {
if (err || !session) {
accept('Error', false);
} else {
data.session = new Session(data, session);
accept(null, true);
}
});
} else {
return accept('No cookie transmitted.', false);
}
});
I am not getting any thing in the session object. I tried to log the contents of the sessionStore and it seems to be empty! Does that mean the information I am storing in the session isn't being stored in the sessionStore? If yes, what should I do to store it there? and if it is stored there why isn't the sessionStore.get function unable to find it?

Answer 1

I am not sure if you're still working on this, but you can access session data with just a MemoryStore. After all how else would Express use it if it didn't work? :)
A simple way to demonstrate MemoryStore working is this:
var express = require("express")
, app = express()
, sessionStore = new express.session.MemoryStore();
// middleware
app.use(express.cookieParser());
app.use(express.session({store: sessionStore, secret: "mysecret"}));
// any endpoint sets a cookie
app.get("/", function(req,res) {
res.send('ok');
});
// This endpoint reveals it
app.get("/session", function(req, res){
sessionStore.get(req.sessionID, function(err, data) {
res.send({err: err, data:data});
});
});
app.listen(3000);
Hitting / followed by /session results in a response of:
{
"err": null,
"data": {
"cookie": {
"originalMaxAge": null,
"expires": null,
"httpOnly": true,
"path": "/"
}
}
}
I suspect your issue may be how you are getting the sessionID from the socket, but it is definitely possible to extract a session from a MemoryStore. Also, remember that restarting the Express server will destroy all of your sessions so you'll need a new cookie after each restart.

Answer 2

You have to use a database to store your express session, then parse the cookie data inside the socket.io definition and with the information obtained get the session info from the database, here is a complete example:
https://stackoverflow.com/a/13098742/218418
You can also use the session ID parsed from the cookie and join the user into a "chat room" with the name of the session.