Node.js RESTful API Development-120%

Designing RESTful APIs with Express.js:

Resource Naming: Each resource should be represented by a unique URI (Uniform Resource Identifier).

HTTP Methods: The CRUD operations on resources should be done by use of http methods namely GET, POST, PUT and DELETE.

Response Codes: Appropriate HTTP status codes should be used to indicate the outcome of API requests.

Request and Response Formats: Data sent to and received from an API should be in standard formats like JSON.

Implementing CRUD Operations:

Let's create an example RESTful API for managing a collection of books:

                                                    
                                                    const express = require('express');
const app = express();

// Middleware for parsing JSON request bodies
app.use(express.json());

let books = [
    { id: 1, title: 'Book 1', author: 'Author 1' },
    { id: 2, title: 'Book 2', author: 'Author 2' }
];

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

// GET a specific book by ID
app.get('/books/:id', (req, res) => {
    const bookId = parseInt(req.params.id);
    const book = books.find(book => book.id === bookId);
    if (book) {
        res.json(book);
    } else {
        res.status(404).json({ message: 'Book not found' });
    }
});

// POST a new book
app.post('/books', (req, res) => {
    const { title, author } = req.body;
    const newBook = { id: books.length + 1, title, author };
    books.push(newBook);
    res.status(201).json(newBook);
});

// PUT (update) an existing book by ID
app.put('/books/:id', (req, res) => {
    const bookId = parseInt(req.params.id);
    const { title, author } = req.body;
    const index = books.findIndex(book => book.id === bookId);
    if (index !== -1) {
        books[index] = { id: bookId, title, author };
        res.json(books[index]);
    } else {
        res.status(404).json({ message: 'Book not found' });
    }
});

// DELETE a book by ID
app.delete('/books/:id', (req, res) => {
    const bookId = parseInt(req.params.id);
    const index = books.findIndex(book => book.id === bookId);
    if (index !== -1) {
        books.splice(index, 1);
        res.status(204).send();
    } else {
        res.status(404).json({ message: 'Book not found' });
    }
});

const port = 3000;
app.listen(port, () => {
    console.log(`Server running at http://localhost:${port}`);
});

Handling Request Parameters, Query Strings, and Request Bodies:

Request Parameters (req.params): These are used for accessing parameters within the URL path such as /books/:id.

Query Strings (req.query): These are used for accessing parameters within the URL query string e.g., /books?category=fiction.

Request Body (req.body): This is used to access data passed in the request body such as JSON data for creating or updating resources.