MVC Architecture in Node.js – Chethan S Poojary

MVC (Model-View-Contoller) is a software design pattern that separates the application logic into three interconnected components:

Model: Manages data and business logic.
View: Handles the UI and presentation
Controller: Act as an interface between Model and View, handling user input and coordinating actions.

MVC in a Node.js App

A typical folder structure using MVC in Node.js (with Express):

project/
│
├── models/
│   └── userModel.js
│
├── views/
│   └── userView.ejs
│
├── controllers/
│   └── userController.js
│
├── routes/
│   └── userRoutes.js
│
├── app.js
└── package.json

MVC Example

1. Model – `models/userModel.js`

Handles data (in real apps, this connects to a database like MongoDB).

// models/userModel.js
const users = [{ id: 1, name: 'Chethan' }];

exports.getAllUsers = () => users;

exports.getUserById = (id) => users.find(user => user.id === id);

2. View – `views/userView.ejs`

Displays user data.

<!-- views/userView.ejs -->
<!DOCTYPE html>
<html>
<head><title>User List</title></head>
<body>
  <h1>User List</h1>
  <ul>
    <% users.forEach(user => { %>
      <li><%= user.name %></li>
    <% }) %>
  </ul>
</body>
</html>

3. Controller – `controllers/userController.js`

Connect Model and View.

// controllers/userController.js
const userModel = require('../models/userModel');

exports.getUsers = (req, res) => {
  const users = userModel.getAllUsers();
  res.render('userView', { users });
};

4. Route – `routes/userRoutes.js`

Defines route to controller logic.

// routes/userRoutes.js
const express = require('express');
const router = express.Router();
const userController = require('../controllers/userController');

router.get('/users', userController.getUsers);

module.exports = router;

5. Main App File – `app.js`

Sets up the Express server.

// app.js
const express = require('express');
const app = express();
const userRoutes = require('./routes/userRoutes');

app.set('view engine', 'ejs');
app.use('/', userRoutes);

app.listen(3000, () => console.log('Server running on http://localhost:3000'));

Followinf MVC structure on your project you can write clean code by separating code and esay to maintain and testing. These are scalable for large application.