RESTful APIs

• Topic: "Building RESTful APIs with Node.js and Express"
• Description: How to design and build RESTful APIs using Node.js and Express.

Content:

1. Introduction to RESTful APIs

• What is REST: Explain REST (Representational State Transfer) and its principles.
• HTTP Methods: Discuss common HTTP methods: GET, POST, PUT, DELETE, PATCH.

2. Setting Up the Project

• Project Initialization:
  

  mkdir myapi
  cd myapi
  npm init -y
  npm install express body-parser
  

• Project Structure:
  

  myapi/
  ├── node_modules/
  ├── package.json
  ├── index.js
  

3. Creating a Simple API

• Basic Express Setup:
  

  const express = require('express');
  const bodyParser = require('body-parser');
  const app = express();
  const port = 3000;
  
  app.use(bodyParser.json());
  
  app.listen(port, () => {
    console.log(`API running at http://localhost:${port}`);
  });
  

4. Defining Routes

• Sample Routes:
  

  let books = [];
  
  app.get('/books', (req, res) => {
    res.json(books);
  });
  
  app.post('/books', (req, res) => {
    const book = req.body;
    books.push(book);
    res.status(201).json(book);
  });
  
  app.get('/books/:id', (req, res) => {
    const book = books.find(b => b.id === parseInt(req.params.id));
    if (book) {
      res.json(book);
    } else {
      res.status(404).send('Book not found');
    }
  });
  
  app.put('/books/:id', (req, res) => {
    const index = books.findIndex(b => b.id === parseInt(req.params.id));
    if (index !== -1) {
      books[index] = req.body;
      res.json(books[index]);
    } else {
      res.status(404).send('Book not found');
    }
  });
  
  app.delete('/books/:id', (req, res) => {
    books = books.filter(b => b.id !== parseInt(req.params.id));
    res.status(204).send();
  });
  

5. Testing the API

• Using Postman or Curl: Demonstrate how to use Postman or Curl to test API endpoints.
• Example Tests:
  • GET /books
  • POST /books with JSON body {"id": 1, "title": "1984", "author": "George Orwell"}
  • GET /books/1
  • PUT /books/1 with JSON body {"id": 1, "title": "Animal Farm", "author": "George Orwell"}
  • DELETE /books/1