Sunday 5 May 2024

Building a Real-Time Chat Application Project in Node JS with MongoDB

In today's fast-paced digital world, real-time communication has become a necessity for many applications. Whether it's collaborating with team members, providing customer support, or simply connecting friends and family, the demand for real-time chat applications is ever-growing. In this article, we'll delve into the process of building a real-time chat application using Node.js and MongoDB, two powerful technologies that complement each other seamlessly.

Building a Real-Time Chat Application Project in Node JS with MongoDB

Why Node.js and MongoDB?

Node.js is a popular runtime environment for building scalable and efficient server-side applications. Its event-driven architecture and non-blocking I/O make it an excellent choice for real-time applications such as chat. MongoDB, on the other hand, is a flexible and scalable NoSQL database that stores data in JSON-like documents, making it well-suited for handling the unstructured data typically found in chat applications.

Feature of Chat Application

1. User Registration

User registration allows individuals to create an account on your chat application. To implement this feature:

  • Create User Schema: Use Mongoose to define a schema for users. Include fields such as username, email, password (hashed using bcrypt), profile picture, and any other relevant information.
  • Registration Endpoint: Set up an endpoint in Express to handle user registration requests. Validate incoming data using Joi, hash the password using bcrypt, and then save the user data to MongoDB using Mongoose.
  • User Authentication: Upon successful registration, generate a JWT token using jsonwebtoken and send it back to the client. This token will be used for subsequent authentication.

2. User Login using JSON Web Token

User login allows registered users to authenticate themselves and access the chat application. Here's how to implement it:

  • Login Endpoint: Create an endpoint to handle user login requests. Validate the user's credentials (username/email and password), compare the hashed password with the stored hash in the database, and if they match, generate a JWT token and send it back to the client.
  • Token Storage: Store the JWT token securely on the client-side (e.g., in local storage or cookies) to be sent along with subsequent requests for authentication.
  • Middleware for Authentication: Create a middleware function in Express to verify the JWT token on protected routes. If the token is valid, allow access to the requested resource; otherwise, return a 401 Unauthorized error.

3. Edit User Profile Data with Image Upload

This feature enables users to update their profile information, including uploading a new profile picture. Here's how to implement it:

  • Profile Update Endpoint: Create an endpoint to handle profile update requests. Allow users to update fields such as username, email, bio, etc. For profile picture updates, use Multer to handle file uploads and save the image to a designated folder.
  • Link Profile Picture to User: Store the file path or URL of the uploaded profile picture in the user document in MongoDB.
  • Secure File Uploads: Implement validation and security measures to prevent unauthorized file uploads and ensure that only allowed file types and sizes are accepted.

4. Search User

This feature allows users to search for other users within the chat application. Here's how to implement it:

  • Search Endpoint: Create an endpoint to handle user search queries. Accept search parameters such as username or email and query the user database in MongoDB to find matching users.
  • Return Search Results: Send the list of matching users back to the client as a response.

5. Display Search Request Notification

When a user receives a search request, they should be notified. Here's how to implement it:

  • Real-Time Notifications: Use to emit a notification event to the recipient user when they receive a search request.
  • Display Notification: Implement client-side logic to display the notification to the user in real-time, such as using toast notifications or updating the UI dynamically.

6. Accept Search Request

This feature allows users to accept incoming search requests. Here's how to implement it:

  • Accept Request Endpoint: Create an endpoint to handle requests to accept incoming search requests. Update the status of the search request in the database to indicate acceptance.
  • Real-Time Updates: Emit a notification event to the sender of the search request to inform them that their request has been accepted.

7. List Accepted Search Request User

Users should be able to see a list of users who have accepted their search requests. Here's how to implement it:

  • List Accepted Requests Endpoint: Create an endpoint to retrieve a list of users who have accepted the current user's search requests.
  • Return Accepted Users: Send the list of accepted users back to the client as a response.

8. Start Chat with other User

This feature enables users to initiate a chat with other users. Here's how to implement it:

  • Chat Initiation Endpoint: Create an endpoint to handle requests to start a chat with another user. Store the chat information in the database, including the participants and any initial messages.
  • Real-Time Chat: Use to establish real-time communication between users in the chat. Emit events for sending and receiving messages, typing indicators, etc.

9. Display User Online Offline Status

Users should be able to see the online/offline status of other users. Here's how to implement it:

  • Real-Time Status Updates: Use to emit events for updating the online/offline status of users in real-time.
  • Update User Status: Implement logic on the server-side to update the user's status in the database based on their activity (e.g., logging in/out).

By implementing these features, you can create a comprehensive and user-friendly chat application that provides a seamless communication experience for your users.

Setting Up the Environment

Before we start building our chat application, let's ensure we have Node.js and MongoDB installed on our system. Once installed, we can create a new directory for our project and initialize a new Node.js project using npm.

		mkdir node-chat
		cd node-chat

Next, let's install the necessary dependencies:

1. Express

		npm install express

Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. It simplifies the process of building web servers and handling HTTP requests by providing a simple and intuitive API.

In our chat application, we use Express to:

  • Set up our server and define routes for handling HTTP requests.
  • Serve static files such as HTML, CSS, and client-side JavaScript.
  • Implement middleware for parsing incoming request bodies and handling errors.

2. Multer

		npm install multer

Multer is a middleware for handling multipart/form-data, which is primarily used for uploading files. While our chat application may not require file uploads, it's a good practice to include Multer for handling any future enhancements that may involve file uploads.

3. Mongoose

		npm install mongoose

Mongoose is an elegant MongoDB object modeling tool designed to work in an asynchronous environment. It provides a straightforward schema-based solution to model application data, validate incoming data, and perform CRUD operations on MongoDB databases.

In our chat application, Mongoose helps us:

  • Define schemas for our MongoDB documents, such as user profiles and chat messages.
  • Create models based on these schemas to interact with the MongoDB database.
  • Perform data validation and define relationships between different types of data.

4. Joi

		npm install joi

Joi is a powerful schema description language and data validator for JavaScript. It allows us to define schemas for the data our application expects to receive, validate incoming data against these schemas, and provide helpful error messages if validation fails.

In our chat application, Joi can be used to:

  • Validate incoming requests to ensure that they contain the expected data in the correct format.
  • Sanitize and coerce incoming data to ensure consistency and security.
  • Handle validation errors gracefully and provide meaningful feedback to the user.

5. Bcrypt

		npm install bcrypt

Bcrypt is a widely-used library for hashing passwords in Node.js applications. It provides a secure way to hash passwords before storing them in the database, making it difficult for attackers to reverse-engineer passwords even if they gain access to the database.

In our chat application, Bcrypt is essential for:

  • Hashing user passwords before storing them in the database to protect user accounts from unauthorized access.
  • Comparing hashed passwords during the authentication process to verify the identity of users.

6. Jsonwebtoken

		npm install jsonwebtoken

Jsonwebtoken is a library for generating and verifying JSON Web Tokens (JWTs) in Node.js applications. JWTs are a compact and self-contained way of representing claims between parties, making them ideal for authentication and information exchange.

In our chat application, Jsonwebtoken is used for:

  • Generating JWTs when users successfully authenticate with the server.
  • Verifying JWTs when users make requests to protected routes, ensuring that they are authorized to access the requested resources.

By leveraging these libraries in our chat application, we can ensure that our application is secure, efficient, and scalable, while also providing a seamless user experience.


In this article, we've covered the process of building a real-time chat application using Node.js and MongoDB. By leveraging the power of for real-time communication and MongoDB for data storage, we've created a scalable and efficient chat application that can handle a large number of users simultaneously. With some additional features and enhancements, you can further customize and extend this application to meet your specific requirements.

Beyond its practical applications, this Node.js chat application project can serve as a valuable educational resource for students and by incorporating this Node.js chat application project into educational curricula or as part of self-directed learning, students can gain practical experience in building real-world applications while reinforcing core concepts in web development, software engineering, and computer science. Whether used as a standalone project or as part of a larger curriculum, this project offers a valuable opportunity for hands-on learning and skill development.


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