Added REST API with Full CRUD Functionality to Flask-ToDo App

README.md

@@ -1,45 +1,173 @@
-Simple Flask Todo App using SQLAlchemy and SQLite database.
+# Flask Todo App with REST API
 
-For styling [semantic-ui](https://semantic-ui.com/) is used.
+This project enhances a simple Flask-based Todo web application by adding a full-featured REST API. The API enables external systems to create, read, update, and delete todo items programmatically, following RESTful principles.
 
-### Setup
-Create project with virtual environment
+## 📌 Original Application
 
-```console
-$ mkdir myproject
-$ cd myproject
-$ python3 -m venv venv
+The original application is a basic Todo list manager built with Flask and SQLite. It supports:
+
+- Viewing all tasks
+- Adding new tasks
+- Updating tasks (marking them as complete/incomplete)
+- Deleting tasks
+
+All actions were handled through HTML forms in the web interface.
+
+## ✨ Enhancements Made
+
+This version introduces a REST API layer that exposes the core functionality through JSON-based HTTP endpoints. Key improvements include:
+
+- Added full CRUD API endpoints under `/api/todos`
+- Returns proper HTTP status codes (200, 201, 400, 404, etc.)
+- Includes input validation and error handling
+- SQLite database for local storage
+- Easy to test with Postman or similar tools
+- Developed a dedicated test suite using `pytest` with 100% test coverage
+
+## 📁 Project Structure
+
+```
+📦 flask-todo
+┣ 📜 app.py
+┣ 📜 app_withRESTAPI.py
+┣ 📜 templates/
+┃ ┗ 📜 index.html
+┣ 📜 test_app.py
+┗ 📜 README.md
 ```
 
-Activate it
-```console
-$ . venv/bin/activate
+> All enhancements are done inside the `feature/rest-api` branch.
+
+---
+
+## 📋 API Documentation
+
+### `GET /api/todos`
+
+Fetches all todo items.
+
+- **Response**: `200 OK`
+```json
+[
+  {
+    "id": 1,
+    "title": "Buy milk",
+    "description": "2 bottles",
+    "done": false
+  }
+]
 ```
 
-or on Windows
-```console
-venv\Scripts\activate
+### `POST /api/todos`
+
+Creates a new todo item.
+
+- **Request JSON**:
+```json
+{
+  "title": "Read book",
+  "description": "Chapter 4",
+  "done": false
+}
 ```
+- **Response**: `201 Created` with new task JSON  
+- **Error**: `400 Bad Request` if title is missing
 
-Install Flask
-```console
-$ pip install Flask
-$ pip install Flask-SQLAlchemy
+### `PUT /api/todos/<id>`
+
+Updates a specific todo item.
+
+- **Request JSON**:
+```json
+{
+  "title": "Finish report",
+  "done": true
+}
 ```
+- **Response**: `200 OK` with updated task  
+- **Error**: `404 Not Found` if the task does not exist
+
+### `DELETE /api/todos/<id>`
+
+Deletes a specific todo item.
+
+- **Response**: `200 OK` with confirmation message  
+- **Error**: `404 Not Found` if the task does not exist
+
+---
+
+## 🚀 How to Run the Project
+
+### 1. Clone the repository:
 
-Set environment variables in terminal
-```console
-$ export FLASK_APP=app.py
-$ export FLASK_ENV=development
+```bash
+git clone https://github.com/alliah2025/flask-todo.git
+cd flask-todo
 ```
 
-or on Windows
-```console
-$ set FLASK_APP=app.py
-$ set FLASK_ENV=development
+### 2. Create a virtual environment and activate it:
+
+```bash
+python -m venv venv
+venv\Scripts\activate  # On Windows
+# or
+source venv/bin/activate  # On Unix/macOS
+```
+
+### 3. Install dependencies:
+
+```bash
+pip install Flask Flask-SQLAlchemy
 ```
 
-Run the app
-```console
-$ flask run
+### 4. Initialize the database:
+
+```python
+# Run this in a Python shell or a separate script
+from app_withRESTAPI import db, app
+with app.app_context():
+    db.create_all()
+    print("Database initialized.")
+```
+
+### 5. Start the Flask app:
+
+```bash
+python app_withRESTAPI.py
+```
+
+- Web interface: [http://localhost:5000](http://localhost:5000)
+- API endpoint: [http://localhost:5000/api/todos](http://localhost:5000/api/todos)
+
+You can test the API using Postman:
+
+- `GET /api/todos` — List all todos
+- `POST /api/todos` — Create a new todo
+- `GET /api/todos/<id>` — Get a specific todo
+- `PUT /api/todos/<id>` — Update a specific todo
+- `DELETE /api/todos/<id>` — Delete a specific todo
+
+---
+
+## 🧪 Testing
+
+All API endpoints have been covered by unit tests using `pytest`.
+
+- Positive and negative test cases for all CRUD operations
+- Uses an in-memory SQLite database for clean and repeatable test runs
+
+To run tests:
+
+```bash
+pytest test_app.py --cov=.
 ```
+
+---
+
+## 🎥 Video Presentation
+https://drive.google.com/drive/folders/10kQL25MgmE4RkZQBb37zw3szmufZ7SvA?usp=sharing
+
+## 📌 Repository Links
+
+- 🔗 Original Repository: https://github.com/patrickloeber/flask-todo.git  
+- 🔗 Forked with Enhancements: https://github.com/alliah2025/flask-todo/tree/feature/rest-api

app_withRESTAPI.py

@@ -0,0 +1,79 @@
+from flask import Flask, request, jsonify
+from flask_sqlalchemy import SQLAlchemy
+
+app = Flask(__name__)
+app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///todo.db'
+app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
+db = SQLAlchemy(app)
+
+class Task(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    title = db.Column(db.String(100), nullable=False)
+    description = db.Column(db.String(200))
+    done = db.Column(db.Boolean, default=False)
+
+    def to_dict(self):
+        return {
+            'id': self.id,
+            'title': self.title,
+            'description': self.description,
+            'done': self.done
+        }
+
+@app.route('/api/todos', methods=['GET'])
+def get_todos():
+    todos = Task.query.all()
+    return jsonify([todo.to_dict() for todo in todos]), 200
+
+@app.route('/api/todos/<int:id>', methods=['GET'])
+def get_task(id):
+    task = db.session.get(Task, id)  # updated here
+    if not task:
+        return jsonify({'error': 'Task not found'}), 404
+    return jsonify(task.to_dict()), 200
+
+@app.route('/api/todos', methods=['POST'])
+def create_todo():
+    data = request.get_json()
+    if not data or 'title' not in data:
+        return jsonify({'error': 'Title is required'}), 400
+    todo = Task(
+        title=data['title'],
+        description=data.get('description', ''),
+        done=data.get('done', False)
+    )
+    db.session.add(todo)
+    db.session.commit()
+    return jsonify(todo.to_dict()), 201
+
+@app.route('/api/todos/<int:id>', methods=['PUT'])
+def update_todo(id):
+    todo = db.session.get(Task, id)  # updated here
+    if not todo:
+        return jsonify({'error': 'Task not found'}), 404
+    data = request.get_json()
+    if 'title' in data:
+        todo.title = data['title']
+    if 'description' in data:
+        todo.description = data['description']
+    if 'done' in data:
+        todo.done = data['done']
+    db.session.commit()
+    return jsonify(todo.to_dict()), 200
+
+@app.route('/api/todos/<int:id>', methods=['DELETE'])
+def delete_todo(id):
+    todo = db.session.get(Task, id)  # updated here
+    if not todo:
+        return jsonify({'error': 'Task not found'}), 404
+    db.session.delete(todo)
+    db.session.commit()
+    return jsonify({'message': 'Todo deleted'}), 200
+
+@app.route('/')
+def home():
+    return "Welcome to the Flask TODO API!"
+
+if __name__ == '__main__':
+    app.run(debug=True)
+

init_db.py

@@ -0,0 +1,7 @@
+##needed to run the flask app
+from app import app, db
+
+with app.app_context():
+    db.create_all()
+    print("Database initialized.")
+

init_dbRESTAPI.py

@@ -0,0 +1,5 @@
+##needed to run the flask app
+from app_withRESTAPI import db, app
+with app.app_context():
+    db.create_all()
+    print("Database initialized.")

test_app.py

@@ -0,0 +1,95 @@
+import pytest
+import json
+from app_withRESTAPI import app, db, Task
+
+@pytest.fixture
+def client():
+    app.config['TESTING'] = True
+    app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///:memory:'
+    with app.test_client() as client:
+        with app.app_context():
+            db.create_all()
+        yield client
+        with app.app_context():
+            db.drop_all()
+
+def test_create_todo_success(client):
+    res = client.post('/api/todos', json={'title': 'Test task'})
+    assert res.status_code == 201
+    data = res.get_json()
+    assert data['title'] == 'Test task'
+    assert data['done'] is False
+
+def test_create_todo_fail_no_title(client):
+    res = client.post('/api/todos', json={'description': 'No title here'})
+    assert res.status_code == 400
+    data = res.get_json()
+    assert 'error' in data
+
+def test_get_todos_empty(client):
+    res = client.get('/api/todos')
+    assert res.status_code == 200
+    assert res.get_json() == []
+
+def test_get_todo_not_found(client):
+    res = client.get('/api/todos/999')
+    assert res.status_code == 404
+    data = res.get_json()
+    assert 'error' in data
+
+def test_update_todo_not_found(client):
+    res = client.put('/api/todos/999', json={'title': 'New title'})
+    assert res.status_code == 404
+    assert 'error' in res.get_json()
+
+def test_delete_todo_not_found(client):
+    res = client.delete('/api/todos/999')
+    assert res.status_code == 404
+    data = res.get_json()
+    assert 'error' in data
+
+def test_crud_flow(client):
+    # Create
+    res = client.post('/api/todos', json={'title': 'First task'})
+    assert res.status_code == 201
+    todo = res.get_json()
+    todo_id = todo['id']
+
+    # Read
+    res = client.get(f'/api/todos/{todo_id}')
+    assert res.status_code == 200
+    assert res.get_json()['title'] == 'First task'
+
+    # Update
+    res = client.put(f'/api/todos/{todo_id}', json={'done': True})
+    assert res.status_code == 200
+    assert res.get_json()['done'] is True
+
+    # Delete
+    res = client.delete(f'/api/todos/{todo_id}')
+    assert res.status_code == 200
+
+    # Confirm Deletion
+    res = client.get(f'/api/todos/{todo_id}')
+    assert res.status_code == 404
+
+def test_full_update_todo(client):
+    # Create a todo first
+    res = client.post('/api/todos', json={'title': 'Temp title'})
+    assert res.status_code == 201
+    todo = res.get_json()
+    todo_id = todo['id']
+
+    # Update both title and description
+    res = client.put(f'/api/todos/{todo_id}', json={'title': 'Updated title', 'description': 'Updated desc'})
+    assert res.status_code == 200
+    data = res.get_json()
+    assert data['title'] == 'Updated title'
+    assert data['description'] == 'Updated desc'
+
+    # Read updated todo
+    res = client.get(f'/api/todos/{todo_id}')
+    assert res.status_code == 200
+    data = res.get_json()
+    assert data['title'] == 'Updated title'
+    assert data['description'] == 'Updated desc'