Implementing RESTful Routes with Node.js and Express

In this article, we’ll dive into building a RESTful API using Node.js and Express. RESTful APIs are a common way to design web services that adhere to the principles of Representational State Transfer (REST), providing a standardized approach for creating, updating, deleting, and retrieving resources over HTTP.

We’ll cover the following topics:

1. Setting Up Your Project
2. Creating the Server
3. Defining Routes
4. Handling CRUD Operations
5. Testing the API

Let’s get started!

1. Setting Up Your Project

First, ensure you have Node.js installed on your system. You can initialize a new Node.js project by running:

mkdir my-rest-api 
cd my-rest-api    
npm init -y

Next, install Express, a minimalist web framework for Node.js:

npm install express

Create a new file named index.js to serve as the entry point of your application.

2. Creating the Server

In index.js, set up a basic Express server:

const express = require('express');
const app = express();
const PORT = process.env.PORT || 3000;

app.use(express.json());

app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});

3. Defining Routes

Define routes for your RESTful API. For example, let’s create routes for managing a collection of products:

let products = [
  { id: 1, name: 'Product A', price: 10.99 },
  { id: 2, name: 'Product B', price: 20.49 }
];

// GET all products
app.get('/products', (req, res) => {
  res.json(products);
});

// GET a single product
app.get('/products/:id', (req, res) => {
  const id = parseInt(req.params.id);
  const product = products.find(prod => prod.id === id);
  if (!product) {
    return res.status(404).json({ message: 'Product not found' });
  }
  res.json(product);
});

// POST a new product
app.post('/products', (req, res) => {
  const { name, price } = req.body;
  const id = products.length + 1;
  const newProduct = { id, name, price };
  products.push(newProduct);
  res.status(201).json(newProduct);
});

// PUT (update) an existing product
app.put('/products/:id', (req, res) => {
  const id = parseInt(req.params.id);
  const { name, price } = req.body;
  const product = products.find(prod => prod.id === id);
  if (!product) {
    return res.status(404).json({ message: 'Product not found' });
  }
  product.name = name;
  product.price = price;
  res.json(product);
});

// DELETE a product
app.delete('/products/:id', (req, res) => {
  const id = parseInt(req.params.id);
  products = products.filter(prod => prod.id !== id);
  res.sendStatus(204);
});

4. Handling CRUD Operations

In the above code:

• GET /products: Retrieves all products.
• GET /products/:id: Retrieves a single product by ID.
• POST /products: Creates a new product.
• PUT /products/:id: Updates an existing product by ID.
• DELETE /products/:id: Deletes a product by ID.

Make sure to use appropriate error handling and validation based on your application’s requirements.

5. Testing the API

You can use tools like Postman or curl to test your API endpoints:

 GET all products
curl http://localhost:3000/products

# POST a new product
curl -X POST -H "Content-Type: application/json" -d '{"name":"Product C","price":15.99}' http://localhost:3000/products

Conclusion

In this article, we’ve explored how to implement RESTful routes in a Node.js and Express application. We covered setting up the project, defining routes for CRUD operations, and testing the API. Building RESTful APIs with Node.js and Express provides a scalable and flexible approach to building modern web services.