node.js - NodeJS + Express - Apply session middleware to some routes

Question

I have an Express application with some routes, only two of them need to support sessions. I read everywhere that the middleware definition (app.use(express.session({...) applies only to the routes that comes after it, so I created this sample:

var express = require('express');
var app = express();
app.use(express.bodyParser());

app.get('/path1', function (req, res) {
    res.send('text response');
});


app.use(express.cookieParser());
app.use(express.session({
    secret: 'secret',
    cookie: { maxAge: new Date(Date.now() + 2 * 60 * 1000) }
}));


app.get('/path2', function (req, res) {
    res.session.test = { "test": "test" };
    res.send('text response');
});

app.listen(8088);

But this doesn't work: in /path2 res.session is undefined.
If I move the session middleware definition up - everything works, but I see that sessions are being create when calling /path1 (this is what I want to avoid)

Can someone explain how a single application can use session in only some of the routes.

Thanks!

///// UPDATE //////

After more digging - I figured it out:

Don't use: app.use(express.session({ ... }));
Instead - define the following:

var sessionMiddleware = express.session({
    //session configurations
});

function sessionHandler(req, res, next) { sessionMiddleware(req, res, next); }

Then apply the handler on the specific route/s that need session support:

app.get('/path_that_need_session', sessionHandler, function (req, res) {                     
 /* Do somthing with req.session */  
});

Answer 1

Don't use app.use(express.session({ ... })).

Instead, initialize the session middleware, save a reference to the resulting function then include it directly in the routes you want it on.

var express = require('express'),
    app = express();

var session = express.session({
    //session configuration
});

app.use(app.router);


// must come after app.use(app.router);
app.get('/your/route/here', session, function(req, res){
    // code for route handler goes here
});

Slightly simpler than the answer included in the update (you don't need the wrapper function).