Code (Backend)

Step 6: Testing of Online Chat Application

Below is the Code for Creating above page:

server.js

// server.js
 
const express = require("express");
const mongoose = require("mongoose");
const cors = require("cors");
 
const ChatMessage = require("./models/ChatMessage");
 
const app = express();
const PORT = process.env.PORT || 5000;
 
// Middleware
app.use(cors());
app.use(express.json());
 
// MongoDB Connection
mongoose.connect("Your MongoDB connection string", {
    useNewUrlParser: true,
    useUnifiedTopology: true,
});
 
// Routes
app.get("/messages", async (req, res) => {
    try {
        const messages = await ChatMessage.find();
        res.json(messages);
    } catch (error) {
        console.error(error);
        res.status(500).json({ error: "Internal Server Error" });
    }
});
 
app.post("/messages", async (req, res) => {
    try {
        const { user, message } = req.body;
 
        if (!user || !message) {
            return res
                .status(400)
                .json({ error: "User and message are required" });
        }
 
        const chatMessage = new ChatMessage({
            user,
            message,
        });
 
        await chatMessage.save();
 
        res.status(201).json(chatMessage);
    } catch (error) {
        console.error(error);
        res.status(500).json({ error: "Internal Server Error" });
    }
});
 
// Start the server
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});

ChatMessage.js

// models/ChatMessage.js
 
const mongoose = require('mongoose');
 
const chatMessageSchema = new mongoose.Schema({
    user: { type: String, required: true },
    message: { type: String, required: true },
    timestamp: { type: Date, default: Date.now },
});
 
const ChatMessage = mongoose.model('ChatMessage', chatMessageSchema);
 
module.exports = ChatMessage;

Step 3: To start the server run the following command.

node server.js

Step 4: Creating the frontend of the app by using the following command

cd ..
npx create-react-app chat-frontend
cd chat-frontend

Step 5: Install the required dependencies.

npm install axios react-router-dom socket.io-client

Folder Structure(Frontend):

Folder Structure (Frontend)

Dependencies(Frontend):

"dependencies": {
    "@testing-library/jest-dom": "^5.17.0",
    "@testing-library/react": "^13.4.0",
    "@testing-library/user-event": "^13.5.0",
    "axios": "^1.6.5",
    "react": "^18.2.0",
    "react-dom": "^18.2.0",
    "react-router-dom": "^6.21.1",
    "react-scripts": "5.0.1",
    "socket.io-client": "^4.7.3",
    "styled-components": "^6.1.8",
    "web-vitals": "^2.1.4"
}

Example: Create the required files and add the following code.

App.css

/* src/App.css */
 
body {
    margin: 0;
    padding: 0;
    font-family: 'Arial', sans-serif;
    background-color: #cadcfc;
    color: #00246b;
}
 
.App {
    text-align: center;
}
 
h1 {
    color: #00246b;
}
 
ul {
    list-style-type: none;
    padding: 0;
}
 
li {
    background-color: #8ab6f9;
    margin: 5px;
    padding: 10px;
    border-radius: 5px;
}
 
input {
    padding: 10px;
    margin-right: 10px;
    border: 1px solid #00246b;
    border-radius: 5px;
}
 
button {
    padding: 10px;
    background-color: #00246b;
    color: #cadcfc;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}
 
button:hover {
    background-color: #8ab6f9;
    color: #00246b;
}

ChatRoom.js

// ChatRoom.js
 
import React, { useState, useEffect } from 'react';
 
const ChatRoom = () => {
    const [messages, setMessages] = useState([]);
    const [user, setUser] = useState('');
    const [message, setMessage] = useState('');
 
    const fetchMessages = async () => {
        try {
            const response = await fetch('http://localhost:5000/messages');
            const data = await response.json();
            setMessages(data);
        } catch (error) {
            console.error('Error fetching messages:', error);
        }
    };
 
    const sendMessage = async () => {
        try {
            await fetch('http://localhost:5000/messages', {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                },
                body: JSON.stringify({ user, message }),
            });
 
            // Clear the message input after sending
            setMessage('');
            // Fetch messages to update the list
            fetchMessages();
        } catch (error) {
            console.error('Error sending message:', error);
        }
    };
 
    useEffect(() => {
        // Fetch messages on component mount
        fetchMessages();
        // Poll for new messages every 2 seconds
        const interval = setInterval(() => {
            fetchMessages();
        }, 2000);
 
        return () => clearInterval(interval);
    }, []); // Run only once on mount
 
    return (
        <div>
            <h2>Chat Room</h2>
            <ul>
                {messages.map((message) => (
                    <li key={message._id}>
                        <strong>{message.user}:</strong> {message.message}
                    </li>
                ))}
            </ul>
            <div>
                <input
                    type="text"
                    placeholder="Your name"
                    value={user}
                    onChange={(e) => setUser(e.target.value)}
                />
                <input
                    type="text"
                    placeholder="Type your message..."
                    value={message}
                    onChange={(e) => setMessage(e.target.value)}
                />
                <button onClick={sendMessage}>Send</button>
            </div>
        </div>
    );
};
 
export default ChatRoom;

App.js

//App.js
 
import './App.css';
import ChatRoom from './ChatRoom';
 
function App() {
    return (
        <div className="App">
            <ChatRoom />
        </div>
    );
}
 
export default App;

Step 6: To start the frontend run the following command.

npm start

Output:

Output of Online Chat Application

Online Chat Application Project in Software Development

Online chat application is one of the most common software development projects to date. In this article, we are going to make the Online chat application software development project from scratch, college students. We will be covering all the steps you have to do while developing this project.