How to use cookie parser in express js

by gayathrimohan Updated: Feb 7, 2024

Guide Kit

Express.js is a web application framework for Node.js. It uses middleware like cookie-parser to handle cookies.

The cookie-parser middleware parses incoming cookies. It makes them accessible in your Express application. It simplifies cookie management in your server-side code.

It provides three types of functions:

1. Signed Cookies:

Function: cookieParser(secret)
Uses a secret to sign cookies, enhancing security by preventing tampering.

2.JSON Cookies:

Function: cookieParser()
Parses cookies containing JSON, making it convenient for handling complex data.

3. Encrypted Cookies:

Function: cookieParser(secret, options)
Encrypts cookies to secure sensitive information during transmission.

How to use cookie-parser in express.js:

Install the cookie-parser package: npm install cookie-parser
Need it in your Express app
Use it as middleware in your app
Access cookies in your routes

Express.js uses cookie-parser to parse and handle cookies in web applications.

Some use cases include:

Cookie Parsing: It simplifies the process of parsing incoming cookies from the client. This makes it easy to access and manipulate cookie data in your Express.js application.
Cookie Creation: The server sends cookies in response to the client. This allows you to manage user sessions, authentication tokens, or other client-side data.
Session Management: It facilitates handling session data stored in cookies. This makes it efficient to manage user sessions. It also helps keep track of user-specific information between HTTP requests.
Authentication: We integrate authentication mechanisms. We store and retrieve user authentication tokens or credentials in cookies.
Customizing Cookie Settings: Provides options for customizing cookie settings. Users can define the end time, secure flag, and domain. This offers fine-grained control over cookie behavior.

Here are the key points about the purpose of cookie-parser in Express.js:

Cookie Parsing: cookie-parser is a middleware in Express.js. It parses cookies from the incoming request header. It makes them accessible in the req.cookies object.
Cookie Handling: It simplifies the process of handling cookies. It provides a convenient way to read, parse, and set cookies in the HTTP request and response.
Middleware Integration: It is often used as a middleware. It is to process cookies before they reach route handlers. This makes it easier to work with cookie data throughout the application.
Security Features: cookie-parser also provides options for handling and parsing signed cookies. It adds a layer of security by ensuring that no one has tampered with the cookie data.
Convenience: It abstracts away the complexities of working with raw cookie headers. It lets builders paint with cookies.

In Conclusion, using cookie-parser enhances your app's handling of cookies. It simplifies cookie parsing and provides a convenient way to set and read cookies. It ensures the use of handling sensitive data with encryption. You use it to set appropriate options for your application's needs.

Fig: Preview of the output that you will get on running this code from your IDE.

Code

JavaScriptLines of Code : 50License : Strong Copyleft (CC BY-SA 4.0)

Dependent Libraries :

// create HTTP server
const express = require('express');
const bodyParser = require('body-parser');
const cookieParser = require('cookie-parser');
const cookieSession = require('cookie-session');
const pug = require('pug');
const app = express();

app.set('views', './views');
app.set('view engine', 'pug');

// use json form parser middleware
app.use(bodyParser.json());

// use query string parser middlware
app.use(bodyParser.urlencoded({ extended: true }));


// cookies
app.use(cookieParser());

app.use(cookieSession({
      name   : 'session'
    , keys   : ['abigsecret', 'anothersecret']
    , maxAge : 100 * 60 * 60 * 1000
}));


// setting the cookie here
app.get('/set-cookie', (req,res) => {
    res.setHeader('Cache-Control', 'private');
    res.cookie('__session', '1', { expires: new Date(Date.now() + 900000), httpOnly: true });
    res.send('cookie set...');
});



// And I would like to access it here
app.get('/user' , (req, res) => {
    console.log(req.cookies);
    res.render('pages/user', {cookies: req.cookies})
});

app.listen(3000, () => { console.log('Listening on port 3000')});

doctype html
html
  body
    h1 Rememberme => #{cookies.__session}

Instruction

Follow the steps carefully to get the output easily.

Install Visual Studio Code on your computer.
Open a new folder.
Install - npm init --yes(to install json package file).
Install - npm install --save express.
Install- npm install cookie-parser.
Install- npm install cookie-session.
Install- npm install pug.
Create a new JS file(eg: express.js).
Copy the snippet using the 'copy' and paste it into that JS file.
Remove last four lines of code.
Save the file and open a new terminal, use the 'node filename(express.js)' command to get the output.

I hope you found this useful.

I found this code snippet by searching for 'How to use cookie parser in express js ' you can try any such use case!

Environment Tested

I tested this solution in the following versions. Be mindful of changes when working with other versions.

The solution is created and tested in Visual Studio Code 1.85.1.

Using this solution, we are able to use cookie parser in express js with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to use cookie parser in express js.

FAQ

1. How do I install cookie-parser in my Express.js project?

You can install it using npm: npm install cookie-parser.

2. How to use cookie-parser middleware in Express.js?

In your Express app, require it: const cookieParser = require('cookie-parser'). Then, use app.use(cookieParser()).

3. Can I access cookies in my route handlers after using cookie-parser?

Yes, you can access cookies using req.cookies in your route handlers. Use cookie-parser first.

4. How to set a cookie using cookie-parser?

Use res.cookie('cookieName', 'cookieValue') to set a cookie in Express.js. Use cookie-parser.

5. Is it possible to configure options for cookie-parser?

Yes, you can pass options as arguments when using cookieParser().

For example,

app.use(cookieParser({ option: value })).

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