Redirecting to previous page in Passport.js after authentication (not duplicate) Node.js

Question

I am trying to redirect back to the page when I am redirected to log in. I am using Passport and connect-ensure-login, and the login works, however, it gets annoying having to re-click the link (if you are not logged in, it redirects you to the home page, but the link has a query string). Is there a way to add a redirect URL upon successful log-in?

The redirect URL needs to be dynamic, because it is query strings, and is not dependent upon the user's id or anything like that.

Here is a snippet of my server-side code (please tell me if you need any other snippets because my app.js is 224 lines long and I don't want to post that). app.js:

let express = require( 'express' );
let app = express();
const expressSession = require('express-session')({
    secret: `secret`,
    resave: false,
    saveUninitialized: false
});
  
app.use(expressSession);
const passport = require('passport');
app.use(passport.initialize());
app.use(passport.session());
let path = require( 'path' );
const passportLocalMongoose = require('passport-local-mongoose');
const connectEnsureLogin = require('connect-ensure-login');
var mongoose = require("mongoose");
var bodyParser = require("body-parser");

const Mixed = mongoose.Schema.Types.Mixed;
mongoose.Promise = global.Promise;
mongoose.connect('mongodb://localhost/db', { useNewUrlParser: true, useUnifiedTopology: false });

const Schema = mongoose.Schema;
const UserDetail = new Schema({
  username: String,
  email: Mixed,
  password: String,
  verified: Boolean
});
UserDetail.plugin(passportLocalMongoose);
const UserDetails = mongoose.model('userInfo', UserDetail, 'userInfo');

passport.use(UserDetails.createStrategy());

passport.serializeUser(UserDetails.serializeUser());
passport.deserializeUser(UserDetails.deserializeUser());

app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: true }));

app.use( '/login', express.static( path.join( __dirname, 'login' ) ) );

app.get( '/', connectEnsureLogin.ensureLoggedIn(), ( req, res ) => {
    res.sendFile( __dirname + '/index.html' );
});

app.post('/login', (req, res, next) => {
    passport.authenticate('local',
    (err, user, info) => {
      if (err) {
        return next(err);
      }
  
      if (!user) { 
        return res.redirect('/login?info=' + info); 
      }
  
      req.logIn(user, function(err) {
        if (err) {
          return next(err);
        }
  
        return res.redirect('/');
      });
  
    })(req, res, next);
});
  

app.get('/login', (req, res) => {
    res.sendFile('login/login.html', { root: __dirname })
});
app.get('/register', (req, res) => {
    res.sendFile('login/register.html', { root: __dirname })
});
app.get('/user', connectEnsureLogin.ensureLoggedIn(), (req, res) => {
    res.send({user: req.user})
})
  
app.post('/register', (req, res) =>{
    UserDetails.register({ username: req.body.username, active: false, email: req.body.email }, req.body.password)
    res.redirect('/login')
})

Is there a way to:

Save query string in the session when using connectEnsureLogin.ensureLoggedIn()?
Or save the query string in another way and read that when you go to redirect?

I'm new to Node.js so I followed an example to get the Login to work (sorry, I do not have the example now, I don't know where I found it and I didn't save a copy of it).

Also, this question does not duplicate this SO question because I cannot think of how to implement the answer with my current middleware, connectEnsureLogin.ensureLoggedIn(). If not, please tell me how I can implement @Chovy's answer to use my current situation.

Thanks so much!!!!

Edit:

I think it has something to do with redirectTo in connectEnsureLogin, however, I cannot get it to read the query string. I tried to set redirectTo to req.url but my servers errors with:

    returnTo: req.query
              ^

ReferenceError: req is not defined

Is there a way to do this? Thanks

score 1 · Accepted Answer · answered Jan 18 '21 at 19:46

Sadly, connectEnsureLogin does not provide the customizations needed in your case, however, a simple middleware function does exactly what you want.

At the top, define a middleware function and set a session cookie called RedirectTo:

function auth (req, res, next) {
    if (req.isAuthenticated()) { 
        // user is authenticated, so we do not need to redirect them.
        return next();
    } else {
        // user is not authenticated, so add a session cookie telling our server where to redirect to.
        req.session.redirectTo = req.url;
        // redirect to login with cookie set
        res.redirect('/login');
    }
}

You can use the middleware like this:

app.get( '/', auth, ( req, res ) => {
    //        ^^^^ notice that we use our middleware instead
    res.sendFile( __dirname + '/index.html' );
})

Then, you can read that session cookie in your post request handler like this:

app.post('/login', (req, res, next) => {
    // authentication like normal
    passport.authenticate('local',(err, user, info) => {
      if (err) {
        return next(err);
      }
  
      if (!user) { 
        return res.redirect('/login?info=' + info); 
      }
  
      req.logIn(user, function(err) {
        if (err) {
          return next(err);
        }
        // this is the special part
        // redirect the user to the session cookie if it exists
        var redirectTo = req.session.redirectTo || '/';
        // delete the session cookie so it is not present on the next request
        delete req.session.redirectTo;
        // redirecting the user to where they want to go
        res.redirect(redirectTo || '/');
      });
  
    })(req, res, next);
});

Redirecting to previous page in Passport.js after authentication (not duplicate) Node.js

Edit:

1 Answers1