Expense Calculator ✨
Gallery - Screenshots
Overview
The Expense Calculator is a fullstack web application designed to simplify daily budget management. This application allows users to track their expenses in real time, categorize them and get a complete view of their spending habits.
Visitor Features
- ✨ Add Expenses : Intuitive interface to quickly record your expenses
- 📝 Edit and Delete : Modify or delete your entries at will
- 📊 Categorization : Organize your expenses by categories (food, entertainment, transport, etc.)
- 📊 Real-time tracking: The total updates instantly
- 💾 💾 Data persistence: Your expenses are saved to MySQL database
Backend Architecture
The backend is built in pure PHP, without framework, with a simplified MVC architecture to ensure code maintainability. Data is stored in a MySQL database with proper transaction management.
Backend Explanations
🔌 PHP API
Endpoints are RESTful: POST to add, PUT to modify, DELETE to delete. Each request is validated on the server to prevent SQL injection.
🗄️ Database Structure
A main table depenses with columns: id, description, amount, category, date, user_id. SQL queries use prepared statements for security.
⚡ Session Management
Simple authentication system with PHP sessions. Each user only sees their expenses thanks to session verification and user_id in database.
Key Points
- ✅ Validation: JavaScript for better UX
- Server-side validation : PHP pour la sécurité
- ⚡ AJAX: Asynchronous requests for smooth experience
- 🔐 Security: Protection against SQL injection with prepared statements
Technical Challenges Addressed
Managing synchronization between frontend and backend was key learning. I discovered the importance of validating data on both sides and gracefully handling network errors.