Javascript – Passing context through a URL to NodeJS Express

What I understood from your question is you want to send verification link to the user via email, and you want to include that link in the mail.

Here is one possible solution with demo code using nodemailer package.

const express = require('express');
const nodemailer = require('nodemailer');  // Package used for sending mail to users
const app = express();

const transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: '[email protected]',
        pass: 'test123' // This should be an App password generated from your Gmail account settings
    }
});

// Function to send verification email
function sendVerificationEmail(email, verificationLink) {
    // Email options
    const mailOptions = {
        from: '[email protected]',
        to: email,
        subject: 'Email Verification',
        html: `<p>Please click <a href="${verificationLink}">here</a> to verify your email address.</p>`
    };

    transporter.sendMail(mailOptions, (error, info) => {
        if (error) {
            console.error('Error sending email:', error);
        } else {
            console.log('Email sent:', info.response);
        }
    });
}

// Register route
app.post('/register', (req, res) => {
    const { email } = req.body;

    // without token
    // const verification = `https://www.website.com/verify?value=foo`;

    // using token , first generate token based on the stored user information
    const verificationLink = `https://www.website.com/verify?token=foo`; // Modified to use a token in the query parameter
    // We want that when a user simply clicks on that link, technically they are essentially making a GET request. Therefore, it's better to pass it as a query parameter.


    // Send verification email
    sendVerificationEmail(email, verificationLink);

    res.send('Verification email sent successfully!');
});

app.get("/verify", (req, res) => {
    const { token } = req.query; // Fetching value from query parameter

    // Now this token can be verified against the one previously sent to the user

    // Generally, in the userModel, we create a field named isVerified which has a default value of 0. At the time of registration, when we create a user, we use JWT to generate a token containing user information in encrypted format.
    // Now, when a new user receives the verification email and clicks the link (in our case /verify?token=tokenValue), we decode the token and fetch user information from the database, updating the isVerified field.
    // Now, when the user tries to log in, we check the isVerified field in the database. If it is 1, the user can log in; otherwise, the user can't log in.

    console.log(token);
    res.send("Verified");
});

// Start the server
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});