KHLIBRARY - Library Management System

Project Overview

KHLIBRARY is a comprehensive full-stack web application designed to streamline library operations and enhance user experience in book borrowing and management. The system provides a robust platform for managing book inventories, user accounts, loan transactions, and administrative oversight.

Core Functionalities

User Management: Role-based access control supporting administrators and patrons with distinct privileges
Book Catalog Management: Comprehensive book inventory system with metadata, categorization, and availability tracking
Loan Processing: Automated borrowing workflow with request submission, approval, and return mechanisms
Real-time Availability: Dynamic book availability tracking with quantity management
Administrative Dashboard: Centralized control panel for system oversight and reporting
Search and Discovery: Advanced book search with filtering by title, author, and category
User Profile Management: Self-service portal for viewing borrowed books and loan history

System Capabilities

The application supports multi-user concurrent access, implements secure authentication mechanisms, and provides comprehensive audit trails for all transactions. The system enforces business rules including loan periods, overdue tracking, and fine calculations.

Technology Stack

Frontend Technologies

HTML5: Semantic markup for structured content presentation
CSS3: Modern styling with custom properties, flexbox, and grid layouts
JavaScript (ES6+): Client-side interactivity and asynchronous operations
Font Awesome 6.4.0: Icon library for consistent visual elements

Backend Technologies

PHP 7.4+: Server-side scripting language for business logic implementation
MySQL 5.7+: Relational database management system for data persistence
Apache HTTP Server: Web server with mod_rewrite for URL routing

Architecture Patterns

MVC (Model-View-Controller): Separation of concerns for maintainable codebase
RESTful API: Standardized HTTP methods for resource manipulation
Service Layer Pattern: Business logic encapsulation in dedicated service classes
Repository Pattern: Data access abstraction through model classes

Development Tools

Git: Version control system for source code management
Hoppscotch: API testing and documentation platform
Visual Studio Code: Integrated development environment

Application Architecture

High-Level System Design

The application follows a three-tier architecture comprising presentation, application, and data layers. The presentation layer handles user interface rendering and client-side interactions. The application layer processes business logic through controllers and services. The data layer manages persistence through models and database abstraction.

Component Interaction Flow

Client Browser → Apache Server → PHP Router → Controller → Service → Model → Database
                                      ↓
                                   View (PHP Templates)

Directory Structure

the-robboeb-library/
├── api/                    # RESTful API endpoints
│   └── v1/
│       ├── controllers/    # API request handlers
│       └── index.php       # API router
├── config/                 # Configuration files
│   ├── constants.php       # Application constants
│   └── database.php        # Database configuration
├── database/               # SQL schema and migrations
├── logs/                   # Application error logs
├── public/                 # Publicly accessible files
│   ├── admin/             # Administrative interface
│   ├── assets/            # Static resources (CSS, JS, images)
│   ├── user/              # User interface
│   ├── browse.php         # Book catalog page
│   ├── login.php          # Authentication page
│   └── index.php          # Application entry point
└── src/                   # Application source code
    ├── controllers/       # Business logic controllers
    ├── helpers/           # Utility functions
    ├── middleware/        # Request/response interceptors
    ├── models/            # Data models and ORM
    └── services/          # Business service layer

Security Architecture

Session Management: Secure session handling with configurable timeout (1800 seconds)
Authentication Service: Centralized authentication with role-based access control
Password Security: Hashed password storage using bcrypt algorithm
SQL Injection Prevention: Prepared statements with parameterized queries
XSS Protection: Input sanitization and output escaping
CSRF Protection: Token-based request validation for state-changing operations

Database Schema and Entity Relationships

Entity Relationship Diagram

erDiagram
    USERS ||--o{ LOANS : creates
    BOOKS ||--o{ LOANS : "borrowed in"
    BOOKS }o--|| CATEGORIES : "belongs to"
    BOOKS }o--o{ AUTHORS : "written by"
    BOOK_AUTHORS }o--|| BOOKS : references
    BOOK_AUTHORS }o--|| AUTHORS : references

    USERS {
        int user_id PK
        string email UK
        string password_hash
        string first_name
        string last_name
        enum user_type
        enum status
        datetime created_at
        datetime updated_at
    }

    BOOKS {
        int book_id PK
        string isbn UK
        string title
        text description
        int category_id FK
        int total_quantity
        int available_quantity
        string cover_image
        int publication_year
        string publisher
        datetime created_at
        datetime updated_at
    }

    AUTHORS {
        int author_id PK
        string first_name
        string last_name
        text biography
        datetime created_at
    }

    CATEGORIES {
        int category_id PK
        string name UK
        text description
        datetime created_at
    }

    LOANS {
        int loan_id PK
        int user_id FK
        int book_id FK
        date loan_date
        date due_date
        date return_date
        enum status
        datetime created_at
        datetime updated_at
    }

    BOOK_AUTHORS {
        int book_id FK
        int author_id FK
    }

Application Workflow Sequence

sequenceDiagram
    participant User
    participant Browser
    participant Server
    participant AuthService
    participant Controller
    participant Model
    participant Database

    User->>Browser: Access Application
    Browser->>Server: HTTP Request
    Server->>AuthService: Check Session
    
    alt User Not Authenticated
        AuthService-->>Server: Redirect to Login
        Server-->>Browser: Login Page
        Browser-->>User: Display Login Form
        User->>Browser: Submit Credentials
        Browser->>Server: POST /login
        Server->>AuthService: Validate Credentials
        AuthService->>Model: Query User
        Model->>Database: SELECT user
        Database-->>Model: User Data
        Model-->>AuthService: User Object
        AuthService->>AuthService: Verify Password
        AuthService->>Server: Create Session
        Server-->>Browser: Redirect to Dashboard
    else User Authenticated
        Server->>Controller: Route Request
        Controller->>Model: Fetch Data
        Model->>Database: Execute Query
        Database-->>Model: Result Set
        Model-->>Controller: Data Objects
        Controller->>Server: Render View
        Server-->>Browser: HTML Response
        Browser-->>User: Display Content
    end

Book Borrowing Workflow

flowchart TD
    A[User Browses Books] --> B{Book Available?}
    B -->|Yes| C[Submit Borrow Request]
    B -->|No| D[View Unavailable Status]
    C --> E[Request Pending Approval]
    E --> F{Admin Reviews}
    F -->|Approve| G[Set Due Date]
    F -->|Reject| H[Notify User - Rejected]
    G --> I[Update Book Quantity]
    I --> J[Create Active Loan]
    J --> K[Notify User - Approved]
    K --> L[User Has Book]
    L --> M{Return Book?}
    M -->|Yes| N[Submit Return Request]
    N --> O[Process Return]
    O --> P[Update Book Quantity]
    P --> Q[Calculate Fine if Overdue]
    Q --> R[Mark Loan as Returned]
    R --> S[Update User History]
    M -->|No| T{Check Due Date}
    T -->|Overdue| U[Calculate Daily Fine]
    T -->|Not Due| L

User Flow Guide

Public User Journey

1. Initial Access

User navigates to application URL
System redirects to Browse Books page (homepage eliminated in redesign)
Navigation bar displays: Browse Books, User Profile (if authenticated), Login/Logout

2. Book Discovery

User views book catalog in range-style grid layout
Each book displays: cover image, title, author, availability status
User can search by title or author
User can filter by category
Click on book card to view detailed information

3. Authentication Flow

Click Login button in navigation
Enter email and password credentials
System validates credentials
Upon success, redirect to Browse Books or Admin Dashboard based on role
Session created with 30-minute timeout

Patron User Journey

4. Book Borrowing Process

Browse available books
Click "Borrow" button on desired book
Confirm borrowing request in dialog (displays 14-day loan period)
Request submitted with "pending" status
User redirected to profile to view pending requests

5. Profile Management

Navigate to User Profile from navigation bar
View statistics: Currently Borrowed, Pending Requests, Overdue Books, Due Soon
Pending Requests section displays books awaiting admin approval
Currently Borrowed section shows active loans with:
- Book cover, title, author
- Borrowed date and due date
- Days remaining or overdue status
- Return button for each book

6. Book Return Process

In Currently Borrowed section, click "Return Book" button
Confirm return action in dialog
System processes return immediately
Book quantity updated
Loan marked as returned
User receives success notification

Administrator Journey

7. Admin Dashboard Access

Login with admin credentials
Redirected to Admin Dashboard
View system statistics: Total Books, Active Members, Active Loans, Categories
Access sidebar navigation for all management functions

8. Loan Management

Navigate to Loans Management
View pending loan requests
Review request details (user, book, requested date)
Approve request: Set due date (default 14 days)
Reject request: Provide reason
View active loans with overdue tracking
Process returns (admin-initiated)

9. Book Management

Navigate to Books Management
Add new books with metadata (title, ISBN, author, category, quantity, cover image)
Edit existing book information
Delete books (if no active loans)
Manage book quantities
Upload cover images

10. User Management

Navigate to Users Management
View all registered users
Create new user accounts
Edit user information
Change user roles (patron/admin)
Activate/deactivate accounts

Frontend Documentation

Page Structure

1. Browse Books (`public/browse.php`)

Purpose: Main landing page for book discovery and browsing

Features:

Range-style grid layout with full book covers
Search functionality (title, author)
Category filtering
Availability badges
Quick borrow/view actions
Responsive design (auto-fill grid)

UI Components:

<!-- Navigation Bar -->
<nav class="navbar">
  - Logo and brand name
  - Browse Books link (active)
  - User Profile link
  - Logout button
</nav>

<!-- Search Section -->
<div class="search-section">
  - Search input (text)
  - Category dropdown
  - Search button
</div>

<!-- Books Grid -->
<div class="books-range">
  - Book cards (200px × 300px covers)
  - Availability badge
  - Title and author
  - Borrow/View buttons
</div>

JavaScript Functions:

viewDetails(bookId) - Navigate to book detail page
requestBorrow(bookId, bookTitle) - Submit borrow request
showNotification(message, type) - Display toast notification
logout() - End user session

2. User Profile (`public/user/profile.php`)

Purpose: User dashboard for managing borrowed books and viewing statistics

Features:

Profile header with avatar and user info
Statistics cards (4 metrics)
Pending requests section
Currently borrowed books list
One-click return functionality
Status color coding (overdue/due soon/active)

UI Components:

<!-- Profile Header -->
<div class="profile-header">
  - Avatar circle with initial
  - User name and email
  - Member since date
</div>

<!-- Statistics Grid -->
<div class="stats-grid">
  - Currently Borrowed count
  - Pending Requests count
  - Overdue Books count
  - Due Soon count (3 days)
</div>

<!-- Pending Requests -->
<div class="section">
  - Book cover thumbnail
  - Title and author
  - Status: "Waiting for admin approval"
</div>

<!-- Currently Borrowed -->
<div class="section">
  - Book cover thumbnail
  - Title and author
  - Borrowed date and due date
  - Days remaining/overdue
  - Return button
</div>

JavaScript Functions:

returnBook(loanId, bookTitle) - Submit return request
showNotification(message, type) - Display toast notification
logout() - End user session

3. Book Detail (`public/book-detail.php`)

Purpose: Detailed view of individual book information

Features:

Large book cover display
Complete book metadata
Author biography
Category information
Availability status
Borrow button (if available)

4. Login Page (`public/login.php`)

Purpose: User authentication interface

Features:

Email and password inputs
Remember me checkbox
Login button
Back to Browse Books link
Error message display

CSS Architecture

Brand Colors

/* Primary Colors */
--primary-orange: #ff5722;
--deep-orange: #ee3900;
--light-orange: #ff7e55;

/* Neutral Colors */
--background: #f5f5f5;
--white: #ffffff;
--dark: #212121;
--medium-gray: #616161;
--light-gray: #757575;

/* Status Colors */
--success: #2e7d32;
--warning: #ef6c00;
--error: #c62828;

Responsive Breakpoints

/* Mobile */
@media (max-width: 768px) {
  - Stacked layouts
  - Hamburger menu
  - Full-width cards
}

/* Desktop */
@media (min-width: 769px) {
  - Grid layouts
  - Horizontal navigation
  - Multi-column displays
}

Component Styles

Navigation Bar:

Height: 70px
Background: #ffffff
Border: 3px solid #ff5722
Shadow: 0 2px 12px rgba(0,0,0,0.1)
Position: sticky top

Book Cards:

Border radius: 12px
Shadow: 0 2px 8px rgba(0,0,0,0.08)
Hover: translateY(-6px) + shadow increase
Border: 1px solid #f5f5f5

Buttons:

Primary: #ff5722 background, white text
Secondary: #f5f5f5 background, #424242 text
Border radius: 8px
Padding: 10px 20px
Transition: 0.2s ease

JavaScript Utilities

API Communication

// Fetch wrapper for API calls
fetch(BASE_URL + '/api/v1/endpoint', {
    method: 'POST',
    headers: {
        'Content-Type': 'application/json',
        'Accept': 'application/json'
    },
    credentials: 'same-origin',
    body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => {
    if (data.success) {
        // Handle success
    } else {
        // Handle error
    }
})
.catch(error => {
    // Handle network error
});

Notification System

function showNotification(message, type) {
    // type: 'success', 'error', 'info'
    // Creates toast notification
    // Auto-dismisses after 3 seconds
    // Slide-in/slide-out animations
}

Backend API Documentation

API Base URL

http://localhost/the-robboeb-library/api/v1

Authentication

All API endpoints require session-based authentication. Include credentials in requests:

credentials: 'same-origin'

Response Format

All API responses follow this structure:

{
    "success": true,
    "data": { ... },
    "message": "Operation successful",
    "error": null
}

Error responses:

{
    "success": false,
    "data": null,
    "message": "Error description",
    "error": {
        "code": "ERROR_CODE",
        "message": "Detailed error message"
    }
}

API Endpoints Reference

Authentication Endpoints

POST /api/v1/auth/login

Description: Authenticate user and create session

Request Body:

{
    "email": "[email protected]",
    "password": "password123"
}

Response (200 OK):

{
    "success": true,
    "data": {
        "user_id": 1,
        "email": "[email protected]",
        "first_name": "John",
        "last_name": "Doe",
        "user_type": "patron"
    },
    "message": "Login successful"
}

Errors:

400: Invalid credentials
401: Account inactive
422: Validation error

POST /api/v1/auth/logout

Description: End user session

Response (200 OK):

{
    "success": true,
    "message": "Logout successful",
    "redirect": "/public/browse.php"
}

Book Endpoints

GET /api/v1/books

Description: Retrieve list of books with optional filtering

Query Parameters:

search (string): Search by title or author
category_id (int): Filter by category
available_only (boolean): Show only available books
limit (int): Number of results (default: 1000)
offset (int): Pagination offset (default: 0)

Response (200 OK):

{
    "success": true,
    "data": {
        "books": [
            {
                "book_id": 1,
                "isbn": "978-0-123456-78-9",
                "title": "Sample Book Title",
                "description": "Book description...",
                "category_id": 1,
                "category_name": "Fiction",
                "author_name": "John Smith",
                "total_quantity": 5,
                "available_quantity": 3,
                "cover_image": "https://example.com/cover.jpg",
                "publication_year": 2023,
                "publisher": "Publisher Name",
                "created_at": "2025-01-01 10:00:00"
            }
        ],
        "count": 1
    }
}

GET /api/v1/books/{id}

Description: Retrieve single book details

Response (200 OK):

{
    "success": true,
    "data": {
        "book_id": 1,
        "isbn": "978-0-123456-78-9",
        "title": "Sample Book Title",
        "description": "Detailed book description...",
        "category_id": 1,
        "category_name": "Fiction",
        "author_name": "John Smith",
        "author_bio": "Author biography...",
        "total_quantity": 5,
        "available_quantity": 3,
        "cover_image": "https://example.com/cover.jpg",
        "publication_year": 2023,
        "publisher": "Publisher Name"
    }
}

Errors:

404: Book not found

POST /api/v1/books (Admin Only)

Description: Create new book

Request Body:

{
    "isbn": "978-0-123456-78-9",
    "title": "New Book Title",
    "description": "Book description",
    "category_id": 1,
    "author_id": 1,
    "total_quantity": 5,
    "cover_image": "https://example.com/cover.jpg",
    "publication_year": 2023,
    "publisher": "Publisher Name"
}

Response (201 Created):

{
    "success": true,
    "data": {
        "book_id": 10,
        "isbn": "978-0-123456-78-9",
        "title": "New Book Title"
    },
    "message": "Book created successfully"
}

Errors:

400: Validation error
403: Permission denied
409: ISBN already exists

PUT /api/v1/books/{id} (Admin Only)

Description: Update book information

Request Body: Same as POST (partial updates allowed)

Response (200 OK):

{
    "success": true,
    "data": {
        "book_id": 1,
        "title": "Updated Title"
    },
    "message": "Book updated successfully"
}

DELETE /api/v1/books/{id} (Admin Only)

Description: Delete book (only if no active loans)

Response (200 OK):

{
    "success": true,
    "message": "Book deleted successfully"
}

Errors:

400: Book has active loans
404: Book not found

Loan Endpoints

GET /api/v1/loans

Description: Retrieve loans (admin sees all, patrons see own)

Query Parameters:

user_id (int): Filter by user (admin only)
status (string): Filter by status (active, overdue, returned, pending, rejected)
limit (int): Number of results
offset (int): Pagination offset

Response (200 OK):

{
    "success": true,
    "data": {
        "loans": [
            {
                "loan_id": 1,
                "user_id": 5,
                "user_name": "John Doe",
                "user_email": "[email protected]",
                "book_id": 10,
                "book_title": "Sample Book",
                "isbn": "978-0-123456-78-9",
                "cover_image": "https://example.com/cover.jpg",
                "loan_date": "2025-11-01",
                "due_date": "2025-11-15",
                "return_date": null,
                "status": "borrowed",
                "loan_status": "active",
                "fine_amount": 0,
                "created_at": "2025-11-01 10:00:00"
            }
        ],
        "count": 1
    }
}

GET /api/v1/loans/my

Description: Get current user's loans

Query Parameters:

status (string): Filter by status

Response: Same as GET /api/v1/loans

GET /api/v1/loans/{id}

Description: Get single loan details

Response (200 OK):

{
    "success": true,
    "data": {
        "loan_id": 1,
        "user_id": 5,
        "book_id": 10,
        "book_title": "Sample Book",
        "loan_date": "2025-11-01",
        "due_date": "2025-11-15",
        "return_date": null,
        "status": "borrowed",
        "fine_amount": 0
    }
}

Errors:

403: Cannot view other user's loans (patrons)
404: Loan not found

POST /api/v1/loans/request

Description: Request to borrow a book (patron)

Request Body:

{
    "book_id": 10
}

Response (201 Created):

{
    "success": true,
    "data": {
        "loan_id": 15,
        "book_id": 10,
        "user_id": 5,
        "status": "pending",
        "created_at": "2025-11-18 14:30:00"
    },
    "message": "Borrow request submitted successfully"
}

Errors:

400: Book not available
400: User already has pending request for this book
400: User already borrowed this book
404: Book not found

PUT /api/v1/loans/{id}/approve (Admin Only)

Description: Approve pending loan request

Request Body:

{
    "due_date": "2025-12-02"
}

Response (200 OK):

{
    "success": true,
    "data": {
        "loan_id": 15,
        "status": "borrowed",
        "loan_date": "2025-11-18",
        "due_date": "2025-12-02"
    },
    "message": "Loan approved successfully"
}

Errors:

400: Loan not in pending status
400: Book not available
400: Invalid due date

PUT /api/v1/loans/{id}/reject (Admin Only)

Description: Reject pending loan request

Response (200 OK):

{
    "success": true,
    "data": {
        "loan_id": 15,
        "status": "rejected"
    },
    "message": "Loan rejected successfully"
}

POST /api/v1/loans/{id}/return

Description: Return borrowed book (user can return own books)

Response (200 OK):

{
    "success": true,
    "data": {
        "loan_id": 15,
        "return_date": "2025-11-20",
        "status": "returned",
        "fine_amount": 0
    },
    "message": "Book returned successfully"
}

Errors:

400: Loan not in borrowed status
403: Cannot return other user's books
404: Loan not found

PUT /api/v1/loans/{id}/return (Admin Only)

Description: Process book return (admin-initiated)

Response: Same as POST /api/v1/loans/{id}/return

GET /api/v1/loans/overdue (Admin Only)

Description: Get all overdue loans

Response (200 OK):

{
    "success": true,
    "data": {
        "loans": [
            {
                "loan_id": 10,
                "user_name": "John Doe",
                "book_title": "Sample Book",
                "due_date": "2025-11-10",
                "days_overdue": 8,
                "fine_amount": 8.00
            }
        ],
        "count": 1
    }
}

GET /api/v1/loans/pending (Admin Only)

Description: Get all pending loan requests

Response (200 OK):

{
    "success": true,
    "data": {
        "loans": [
            {
                "loan_id": 15,
                "user_name": "Jane Smith",
                "book_title": "Sample Book",
                "created_at": "2025-11-18 14:30:00"
            }
        ],
        "count": 1
    }
}

User Endpoints

GET /api/v1/users (Admin Only)

Description: Retrieve list of users

Query Parameters:

user_type (string): Filter by type (admin, patron)
status (string): Filter by status (active, inactive)
limit (int): Number of results
offset (int): Pagination offset

Response (200 OK):

{
    "success": true,
    "data": {
        "users": [
            {
                "user_id": 5,
                "email": "[email protected]",
                "first_name": "John",
                "last_name": "Doe",
                "user_type": "patron",
                "status": "active",
                "created_at": "2025-01-15 10:00:00"
            }
        ],
        "count": 1
    }
}

GET /api/v1/users/{id} (Admin Only)

Description: Get single user details

Response (200 OK):

{
    "success": true,
    "data": {
        "user_id": 5,
        "email": "[email protected]",
        "first_name": "John",
        "last_name": "Doe",
        "user_type": "patron",
        "status": "active",
        "created_at": "2025-01-15 10:00:00",
        "updated_at": "2025-11-18 10:00:00"
    }
}

POST /api/v1/users (Admin Only)

Description: Create new user

Request Body:

{
    "email": "[email protected]",
    "password": "SecurePass123!",
    "first_name": "Jane",
    "last_name": "Smith",
    "user_type": "patron"
}

Response (201 Created):

{
    "success": true,
    "data": {
        "user_id": 20,
        "email": "[email protected]",
        "first_name": "Jane",
        "last_name": "Smith"
    },
    "message": "User created successfully"
}

Errors:

400: Validation error
409: Email already exists

PUT /api/v1/users/{id} (Admin Only)

Description: Update user information

Request Body: Same as POST (partial updates allowed)

Response (200 OK):

{
    "success": true,
    "data": {
        "user_id": 5,
        "email": "[email protected]"
    },
    "message": "User updated successfully"
}

DELETE /api/v1/users/{id} (Admin Only)

Description: Delete user (only if no active loans)

Response (200 OK):

{
    "success": true,
    "message": "User deleted successfully"
}

Errors:

400: User has active loans
404: User not found

Category Endpoints

GET /api/v1/categories

Description: Retrieve all categories

Response (200 OK):

{
    "success": true,
    "data": {
        "categories": [
            {
                "category_id": 1,
                "name": "Fiction",
                "description": "Fictional literature",
                "book_count": 25,
                "created_at": "2025-01-01 10:00:00"
            }
        ],
        "count": 1
    }
}

POST /api/v1/categories (Admin Only)

Description: Create new category

Request Body:

{
    "name": "Science Fiction",
    "description": "Science fiction books"
}

Response (201 Created):

{
    "success": true,
    "data": {
        "category_id": 10,
        "name": "Science Fiction"
    },
    "message": "Category created successfully"
}

Author Endpoints

GET /api/v1/authors

Description: Retrieve all authors

Response (200 OK):

{
    "success": true,
    "data": {
        "authors": [
            {
                "author_id": 1,
                "first_name": "John",
                "last_name": "Smith",
                "biography": "Author biography...",
                "book_count": 5,
                "created_at": "2025-01-01 10:00:00"
            }
        ],
        "count": 1
    }
}

POST /api/v1/authors (Admin Only)

Description: Create new author

Request Body:

{
    "first_name": "Jane",
    "last_name": "Doe",
    "biography": "Author biography..."
}

Response (201 Created):

{
    "success": true,
    "data": {
        "author_id": 15,
        "first_name": "Jane",
        "last_name": "Doe"
    },
    "message": "Author created successfully"
}

Installation Guide

Prerequisites

PHP 7.4 or higher
MySQL 5.7 or higher
Apache HTTP Server with mod_rewrite enabled
Git (for version control)

Installation Steps

Clone Repository

git clone https://github.com/robboeb/the-robboeb-library.git
cd the-robboeb-library

Configure Database

# Create database
mysql -u root -p
CREATE DATABASE library_db;
exit;

# Import schema
mysql -u root -p library_db < database/schema.sql

Update Configuration Edit config/database.php:

define('DB_HOST', 'localhost');
define('DB_NAME', 'library_db');
define('DB_USER', 'your_username');
define('DB_PASS', 'your_password');

Edit config/constants.php:

define('BASE_URL', '/the-robboeb-library');
define('APP_NAME', 'KHLIBRARY');

Set Permissions

chmod 755 public/
chmod 755 logs/
chmod 644 config/*.php

Configure Apache Ensure .htaccess is enabled and mod_rewrite is active:

<Directory "/path/to/the-robboeb-library">
    AllowOverride All
    Require all granted
</Directory>

Access Application Navigate to: http://localhost/the-robboeb-library

Default Admin Account

Email: [email protected]
Password: admin123

⚠️ Change default password immediately after first login!

Development Guidelines

Code Standards

Follow PSR-12 coding standards for PHP
Use meaningful variable and function names
Comment complex logic
Keep functions small and focused
Use prepared statements for all database queries

Git Workflow

# Create feature branch
git checkout -b feature/new-feature

# Make changes and commit
git add .
git commit -m "Add new feature"

# Push to repository
git push origin feature/new-feature

# Create pull request for review

Testing

Test all API endpoints with Hoppscotch or Postman
Verify user flows in different browsers
Test responsive design on mobile devices
Check error handling and validation
Verify security measures (authentication, authorization)

Troubleshooting

Common Issues

Issue: Database connection error Solution: Verify database credentials in config/database.php

Issue: 404 errors on all pages Solution: Enable mod_rewrite in Apache and check .htaccess file

Issue: Session timeout too short Solution: Adjust SESSION_TIMEOUT in config/constants.php

Issue: Book covers not displaying Solution: Check image URLs and ensure external images are accessible

Issue: API returns 403 Forbidden Solution: Verify user is authenticated and has proper permissions

Security Best Practices

Implemented Security Measures

✅ Password hashing with bcrypt
✅ Prepared statements (SQL injection prevention)
✅ Input validation and sanitization
✅ Output escaping (XSS prevention)
✅ Session management with timeout
✅ Role-based access control
✅ HTTPS recommended for production

Recommendations

Use HTTPS in production
Implement rate limiting for API endpoints
Regular security audits
Keep dependencies updated
Monitor error logs
Implement CSRF tokens for forms
Use environment variables for sensitive data

Performance Optimization

Database

Indexed columns: user_id, book_id, email, isbn
Optimized queries with JOINs
Connection pooling
Query result caching (recommended)

Frontend

Minified CSS and JavaScript (recommended)
Image optimization
CDN for static assets (Font Awesome, logo)
Lazy loading for images (recommended)
Browser caching headers

Backend

Efficient query design
Pagination for large datasets
Session storage optimization
Error logging without performance impact

Contributing

How to Contribute

Fork the repository
Create feature branch
Make changes with tests
Submit pull request
Wait for code review

Contribution Guidelines

Follow existing code style
Write clear commit messages
Add comments for complex logic
Update documentation
Test thoroughly before submitting

License

This project is licensed under the MIT License - see the LICENSE file for details.

Credits

Developer: eirsvi.t.me
Contact: https://t.me/eirsvi
Repository: https://github.com/robboeb/the-robboeb-library
Version: 2.0
Last Updated: November 18, 2025

Support

For issues, questions, or suggestions:

Open an issue on GitHub
Contact developer via Telegram: https://t.me/eirsvi
Email: [email protected]

Changelog

Version 2.0 (November 18, 2025)

✅ Complete frontend redesign
✅ Eliminated homepage
✅ Range-style book layout
✅ Unified navigation (2 items)
✅ User self-return functionality
✅ Brand color theme implementation
✅ Improved color contrast (WCAG 2.1 AA)
✅ Added favicon to all pages
✅ Developer credits in footer
✅ Fixed UI bugs and stray symbols
✅ Enhanced API with user return endpoint
✅ Comprehensive documentation

Version 1.0 (Initial Release)

Basic library management system
Admin and patron roles
Book catalog management
Loan processing
User management
Search and filtering

Name		Name	Last commit message	Last commit date
Latest commit History 12 Commits
.vscode		.vscode
api		api
config		config
database		database
logs		logs
public		public
src		src
.gitignore		.gitignore
.htaccess		.htaccess
BRAND.txt		BRAND.txt
FRONTEND_REDESIGN_FINAL.md		FRONTEND_REDESIGN_FINAL.md
README.md		README.md
hoppscotch-collection.json		hoppscotch-collection.json
local-sql.txt		local-sql.txt

robboeb/the-robboeb-library

Folders and files

Latest commit

History

Repository files navigation

KHLIBRARY - Library Management System

Project Overview

Core Functionalities

System Capabilities

Technology Stack

Frontend Technologies

Backend Technologies

Architecture Patterns

Development Tools

Application Architecture

High-Level System Design

Component Interaction Flow

Directory Structure

Security Architecture

Database Schema and Entity Relationships

Entity Relationship Diagram

Application Workflow Sequence

Book Borrowing Workflow

User Flow Guide

Public User Journey

1. Initial Access

2. Book Discovery

3. Authentication Flow

Patron User Journey

4. Book Borrowing Process

5. Profile Management

6. Book Return Process

Administrator Journey

7. Admin Dashboard Access

8. Loan Management

9. Book Management

10. User Management

Frontend Documentation

Page Structure

1. Browse Books (public/browse.php)

2. User Profile (public/user/profile.php)

3. Book Detail (public/book-detail.php)

4. Login Page (public/login.php)

CSS Architecture

Brand Colors

Responsive Breakpoints

Component Styles

JavaScript Utilities

API Communication

Notification System

Backend API Documentation

API Base URL

Authentication

Response Format

API Endpoints Reference

Authentication Endpoints

POST /api/v1/auth/login

POST /api/v1/auth/logout

Book Endpoints

GET /api/v1/books

GET /api/v1/books/{id}

POST /api/v1/books (Admin Only)

PUT /api/v1/books/{id} (Admin Only)

DELETE /api/v1/books/{id} (Admin Only)

Loan Endpoints

GET /api/v1/loans

GET /api/v1/loans/my

GET /api/v1/loans/{id}

POST /api/v1/loans/request

PUT /api/v1/loans/{id}/approve (Admin Only)

PUT /api/v1/loans/{id}/reject (Admin Only)

POST /api/v1/loans/{id}/return

PUT /api/v1/loans/{id}/return (Admin Only)

GET /api/v1/loans/overdue (Admin Only)

GET /api/v1/loans/pending (Admin Only)

User Endpoints

GET /api/v1/users (Admin Only)

GET /api/v1/users/{id} (Admin Only)

POST /api/v1/users (Admin Only)

PUT /api/v1/users/{id} (Admin Only)

1. Browse Books (`public/browse.php`)

2. User Profile (`public/user/profile.php`)

3. Book Detail (`public/book-detail.php`)

4. Login Page (`public/login.php`)

Packages