Tutorials

Express req.cookies Property

Posted in Express Tutorial

Updated on Nov 24, 2024

By Mari Selvan

👁️ 64 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

Cookies are a fundamental aspect of web development, enabling developers to store small pieces of information on the client-side. In the context of Express.js, handling cookies is made easy through the req.cookies property.

This guide will walk you through the syntax, usage, and best practices for utilizing req.cookies to manage cookies effectively in your Express.js applications.

💡 Syntax

Accessing cookies using req.cookies in Express.js is straightforward:

syntax.js

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const cookieValue = req.cookies.cookieName;

cookieName: The name of the cookie you want to retrieve.

❓ How req.cookies Works

req.cookies in Express.js provides a convenient way to access cookies sent by the client in the HTTP request. It automatically parses the cookie header and provides a simple interface to read the values associated with each cookie.

example.js

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app.get('/read-cookie', (req, res) => {
  const username = req.cookies.username;
  res.send(`Hello, ${username}!`);
});

In this example, the route handler uses req.cookies to read the value of the "username" cookie and sends a personalized greeting.

📚 Use Cases

User Authentication:

Leverage req.cookies to retrieve user authentication information stored in a cookie.

user-authentication.js

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app.get('/dashboard', (req, res) => {
  const userId = req.cookies.userId;
  // Validate user authentication based on userId
  // Render the user dashboard
});

Remember User Preferences:

Use req.cookies to read user preferences stored in cookies and provide a personalized experience.

user-preferences.js

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app.post('/update-preferences', (req, res) => {
  // Update user preferences in the database
  // Set a cookie to remember the user's preferences
  res.cookie('theme', req.body.theme, { maxAge: 86400000 }); // Cookie expires in 24 hours
  res.send('Preferences updated successfully!');
});

🏆 Best Practices

Secure Cookies:

When setting cookies, consider using the secure option to ensure that the cookie is only sent over HTTPS connections.
secure-cookies.js
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```
res.cookie('sessionId', '123456', { secure: true });
```
Cookie Expiry:

Set an expiry time for cookies using the maxAge option to control how long the client should keep the cookie.
cookie-expiry.js
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```
res.cookie('token', 'abcdef123456', { maxAge: 604800000 }); // Cookie expires in 7 days
```

🎉 Conclusion

The req.cookies property in Express.js simplifies the process of working with cookies in your web applications. Whether it's for user authentication, storing preferences, or other use cases, understanding how to effectively use req.cookies is crucial for building feature-rich and secure Express.js applications.

Now armed with knowledge about req.cookies, go ahead and enhance your Express.js projects with effective cookie management!