Express by Examples

This chapter will describe how to use 'express-session' middleware to authenticate login in NodeJS (ExpressJS).

Visit https://github.com/expressjs/session .

Here will be described File Session Storage.

 

Installation

$ npm install --save express-session

$ npm install --save session-file-store     -for creating session files

 

 

Integration into ExpressJS

Add into /app.js file:

var session = require('express-session');
var FileStore = require('session-file-store')(session);

//file session
var sess_options = {
  path: "./tmp/sessions/",  //directory where session files will be stored
  useAsync: true,
  reapInterval: 5000,
  maxAge: 10000
};
app.use(session({
  store: new FileStore(sess_options),
  secret: 'my_secret_key',
  resave: true,
  saveUninitialized: false
}));

 

Notice: If saveUninitialized is false then session file is not created unless we set req.session.username='val' . Also session file is deleted on req.session.destroy();

If it is true then session file is created each time we run ./app.js file, e.g. each time we run in broweser any page http://localhost:3000 . Also session file is not deleted after we apply req.session.destroy();

 

 

Also add admin route to enable access admin area by http://localhost:3000/admin/

var admin = require('./routes/admin/index');

app.use('/admin', admin);

 

The complete /app.js file will be:

 

/*jslint unparam: true*/

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

//session
var session = require('express-session');
var FileStore = require('session-file-store')(session);

var routes = require('./routes/index');
var admin = require('./routes/admin/index');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'hjs');

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(require('less-middleware')(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'public')));

//session
var sess_options = {
  path: "./tmp/sessions/",
  useAsync: true,
  reapInterval: 5000,
  maxAge: 10000
};
app.use(session({
  store: new FileStore(sess_options),
  secret: '2015tajnikljuc',
  resave: true,
  saveUninitialized: true
}));



app.use('/', routes);
app.use('/admin', admin);

// catch 404 and forward to error handler
app.use(function (req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function (err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function (err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

 

 

Now you can get or set session variable by ‘req.session‘. Just like we do in PHP using $_SESSION variable.

So create /router/admin/index.js

 

 

 /*jslint unparam: true*/

var express = require('express');
var router = express.Router();
var nodedump = require('nodedump').dump;

/* Set session */
router.get('/set', function (req, res, next) {
  req.session.username = 'nesto';

  res.send('Session is set: ' + req.session.username);
});

/* Get session */
router.get('/get', function (req, res, next) {
  res.send(nodedump(req.session.username));
});

module.exports = router;

 

 

Conclusion:

1. Session file is stored into /tmp/sessions/TOBytIuyqPWFx4tW3BIS8s6O6dtcVXlg.json file

{"cookie":{"originalMaxAge":null,"expires":null,"httpOnly":true,"path":"/"},"__lastAccess":1429970672649,"username":"nesto"}

 

2. To set session value use simple: req.session.var = ' value ';

3. To get session variable use: req.session.var;

 

 

Other Session Storages

Besides session-file-store there are many other session storages:

• connect-mongo
• connect-redis
• connect-marklogic