APIs and Servers

Assignment: Build a Simple To-Do List API

Objective:

Create a basic server that allows users to manage a to-do list using an API. You'll learn how to set up a server, create endpoints, and handle HTTP requests.

Tools:

• Node.js (JavaScript runtime)
• Express.js (Web framework for Node.js)
• Postman or cURL (For testing API requests)

Prerequisites:

• Basic understanding of JavaScript
• Familiarity with installing npm packages

Task Breakdown:

1. Set Up Your Project:

   • Create a new folder for the project (e.g., simple-todo-api).

   • Initialize a new Node.js project by running:

     
     npm init -y

   • Install Express.js:

     npm install express
2. Create the Server:

   • Create an index.js file in the project folder.

   • Set up a basic Express server that listens on port 3000:

     const express = require('express');
     const app = express();
     const PORT = 3000;
     
     app.use(express.json());
     
     app.listen(PORT, () => {
       console.log(`Server is running on http://localhost:${PORT}`);
     });
     
3. Create To-Do List Data Storage:

   • Use a simple in-memory array to store to-do items for now:

     let todos = [];
     
4. Implement the Endpoints:
   • Add the following endpoints:

     • GET /todos: Retrieve all to-do items.

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

     • POST /todos: Add a new to-do item.

       
       app.post('/todos', (req, res) => {
         const { task } = req.body;
         const newTodo = { id: todos.length + 1, task };
         todos.push(newTodo);
         res.status(201).json(newTodo);
       });
       

     • PUT /todos/: Update an existing to-do item.

       
       app.put('/todos/:id', (req, res) => {
         const { id } = req.params;
         const { task } = req.body;
         const todo = todos.find((t) => t.id === parseInt(id));
       
         if (todo) {
           todo.task = task;
           res.json(todo);
         } else {
           res.status(404).send('To-Do item not found');
         }
       });
       

     • DELETE /todos/: Delete a to-do item.

       
       app.delete('/todos/:id', (req, res) => {
         const { id } = req.params;
         todos = todos.filter((t) => t.id !== parseInt(id));
         res.status(204).send();
       });
       
5. Test the API:
   • Use Postman or cURL to test each endpoint.
   • Test creating, reading, updating, and deleting to-do items.
6. Bonus (Optional):
   • Add data validation to ensure tasks are not empty.
   • Implement error handling for invalid requests.
   • Save the to-do list data to a file using the fs module in Node.js.

Expected Outcome:

A functioning API server that can manage a to-do list with basic CRUD (Create, Read, Update, Delete) operations.