sessioncode.js

const express = require('express');
const session = require('express-session')
const bodyParser = require('body-parser')
const path = require('path')
const app = express();
const port = 3000;

app.use(session({
   secret: 'Keep it secret',
   name: 'uniqueSessionID',
   saveUninitialized: false
}))

app.get('/', (req, res) => {
   if (req.session.loggedIn)
      res.redirect('/dashboard')
   else
      res.sendFile('home.html', {
         root: path.join(__dirname, 'public')
      })
})

app.get('/dashboard', (req, res) => {
   if (req.session.loggedIn) {
      res.setHeader('Content-Type', 'text/html')
      res.write('Welcome ' + req.session.username + ' to your dashboard')
      res.write('<a href="/logout">Logout</a>')
      res.end()
   } else
      res.redirect('/login')
})

app.get('/login', (req, res) => {
   res.sendFile('login.html', {
      root: path.join(__dirname, 'public')
   })
})

app.post('/authenticate', bodyParser.urlencoded(), (req, res, next) => {
   // Actual implementation would check values in a database
   if (req.body.username == 'foo' && req.body.password == 'bar') {
      res.locals.username = req.body.username
      next()
   } else
      res.sendStatus(401)
}, (req, res) => {
   req.session.loggedIn = true
   req.session.username = res.locals.username
   console.log(req.session)
   res.redirect('/dashboard')
})

app.get('/logout', (req, res) => {
   req.session.destroy((err) => {})
   res.send('Thank you! Visit again')
})

app.listen(port, () => {
   console.log('Website is running')
});