sending variables through res.redirect()

Question

So i'm trying to send user_id to the profile page through res.redirect(). here is my login.js:

const express = require('express')
const router = express.Router()
let alert = require('alert')
const bcrypt = require('bcrypt')
const mysqlConnection = require("../utils/database")

router.post('/', async (req, res) => {

    //Check if user exists in the database
    await new Promise((res, rej) => {
        var sql = "SELECT * FROM usercredentials WHERE username = ?"
        mysqlConnection.query(sql, req.body.username, (err, result) => {
            if(err) throw err
            
            //If result length is bigger than 0 then the user exists in the database
            if(result.length > 0) {
                validUsername = true
                userPassword = result[0].password
                console.log(result)
                var user_id = result.insertId
                res(result)
            } else {
                validUsername = false
                console.log(result)

                res(result)
            }
        })
    })

    //If username is valid then check if password is correct
    if (validUsername == true) {
        const validPassword = await bcrypt.compare(req.body.password, userPassword)
        if (validPassword) {
            console.log('Successful Login')
            req.session.user_id = user_id;
            res.redirect('profile.html')
        } else {
            console.log('Failed Login')
            alert('Failed Login')

            res.redirect('login.html')
        }
    } else {
        console.log('User does not exist')
        alert('User does not exist')

        res.redirect('login.html')
    }
})

module.exports = router

is it possible to send user_id through in res.redirect('profile.html') like res.redirect('profile.html', req.id)? I added my login.js code above

@TusharGupta-curioustushar something like this res.redirect('profile.html', req.id), so I can access user_id from profile.html page. — Bayram, Apr 01 '21 at 06:02
Normally this is done with routing so you have a route like `/profile/:id` and then you make a URL like `/profile/1234`. — tadman, Apr 01 '21 at 06:06
You have Node.js code here so I can only presume you have some kind of web app going on here, not just a "website" which is a much broader term. Is this using Express? — tadman, Apr 01 '21 at 06:11
Does this answer your question? [How do I redirect in expressjs while passing some context?](https://stackoverflow.com/questions/19035373/how-do-i-redirect-in-expressjs-while-passing-some-context) — Tushar Gupta - curioustushar, Apr 01 '21 at 06:19
@tadman could you help me to get the variable from URL? for some reason query is empty — Bayram, Apr 01 '21 at 08:38
if you have proper routes, you'll get params directly in the request object. Express makes this super easy. — tadman, Apr 01 '21 at 20:48

Masood · Accepted Answer · 2021-04-01T06:14:10.460

1

You can send it using URL query.

res.redirect(`login.html?user_id=${user_id}`);

The alternative solution is to store it in session before redirect and get it back from session storage in the next page.

req.session.user_id = user_id;
res.redirect('profile.html');

In profile.html you can access it like:

// From URL query
const userId = req.query.user_id;
// From session
const userId = req.session.user_id;

edited Apr 01 '21 at 06:14

answered Apr 01 '21 at 06:09

Masood

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could you please explain how to parse that user_id on different page after redirecting? – Bayram Apr 01 '21 at 06:12
1

I edited the answer how to get the user_id back. – Masood Apr 01 '21 at 06:15
I get this error for some reason UnhandledPromiseRejectionWarning: TypeError: Cannot set property 'user_id' of undefined – Bayram Apr 01 '21 at 06:23
on which page are you receiving this error, after redirection? and are you storing in session or query? – Masood Apr 01 '21 at 06:24
no before redirection, at the login.html page – Bayram Apr 01 '21 at 06:25
You didn't resolve the promise(). It means when you are checking user in your db or something – Masood Apr 01 '21 at 06:26
Can you share your code where you return the user and check for comparison in login? – Masood Apr 01 '21 at 06:27
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/230620/discussion-between-bayram-jumageldiyev-and-masood). – Bayram Apr 01 '21 at 06:36
i am having trouble parsing the query inside of the profile.js – Bayram Apr 01 '21 at 08:24
@BayramJumageldiyev bro you need to take a full course then – Masood Apr 01 '21 at 09:30

sending variables through res.redirect()

1 Answers1