kodhe / cart

2.0.0 2026-09-28 18:23 UTC

Requires

• php: >=8.1

Requires (Dev)

• phpunit/phpunit: ^9.0

MIT

Published on Packagist.org on 2026-09-29 18:09 UTC

README

A modular, maintainable, and testable shopping cart library for CodeIgniter 3 with PSR-4 and PSR-12 compliance.

Features

• 100% Backward Compatible - All original CodeIgniter 3 Cart API methods preserved
• PSR-4 Autoloading - Proper namespace-based autoloading
• PSR-12 Coding Standards - Clean, modern PHP code
• Multiple Storage Backends - Session, Database, or Memory storage
• Strategy Pattern - Extensible tax, discount, and shipping calculators
• Factory Pattern - Easy cart instantiation with different configurations
• Value Objects - Type-safe CartItem, CartSummary, and CartTotals models
• Dependency Injection - Easy to mock and test
• Performance Optimized - Lazy calculation caching, optimized session writes

Installation

composer require kodhe/cart

Quick Start

use Kodhe\Cart\Cart;

// Create cart (uses session storage by default)
$cart = new Cart();

// Insert item
$cart->insert([
    'id' => 'sku_123',
    'qty' => 2,
    'price' => 29.99,
    'name' => 'T-Shirt',
    'options' => ['Size' => 'L', 'Color' => 'Blue']
]);

// Get cart total
echo $cart->total();

// Display cart contents
print_r($cart->contents());

Advanced Usage

Tax Calculation

$cart->getTaxCalculator()->setTaxRate(10); // 10% tax
$tax = $cart->getTax();

Discount Calculation

$cart->getDiscountCalculator()
    ->applyPercentageDiscount('SAVE10', 10); // 10% off
    
$discount = $cart->getDiscount();

Shipping Calculation

$cart->getShippingCalculator()
    ->setFlatRate(5.99);
    
$shipping = $cart->getShipping();

Grand Total (with tax, shipping, discounts)

$grandTotal = $cart->grandTotal();

Using Different Storage

use Kodhe\Cart\Factory\CartFactory;

// Memory storage (for testing)
$cart = CartFactory::createForTesting('my_test_cart');

// Database storage (for logged-in users)
$cart = CartFactory::createForUser('user_123');

// Custom storage
use Kodhe\Cart\Storage\SessionStorage;
$storage = new SessionStorage();
$cart = new Cart();
$cart->setStorage($storage);

API Reference

All original CodeIgniter 3 Cart methods are available:

Method	Description
insert($items)	Insert single or multiple items
update($items)	Update item quantity or other properties
remove($rowid)	Remove an item from cart
destroy()	Empty the entire cart
total()	Get cart subtotal
total_items()	Get total quantity of items
contents($newest_first)	Get all cart items
product_options($row_id)	Get options for specific item
has_options($row_id)	Check if item has options
format_number($n)	Format number as currency
get_item($row_id)	Get specific item by row ID

New Methods

Method	Description
getTotals()	Get CartSummary with detailed breakdown
getTax()	Get calculated tax amount
getDiscount()	Get calculated discount amount
getShipping()	Get calculated shipping cost
grandTotal()	Get total including tax/shipping minus discounts
getItems()	Get array of CartItem objects
itemCount()	Get number of distinct line items
isEmpty()	Check if cart is empty
getTaxCalculator()	Access tax calculator
getDiscountCalculator()	Access discount calculator
getShippingCalculator()	Access shipping calculator
getStorage()	Get current storage handler
setStorage($storage)	Set custom storage handler

Project Structure

cart/
├── Cart.php                    # Main cart class (backward compatible)
├── Contracts/
│   ├── CartInterface.php       # Cart public API contract
│   ├── CartStorageInterface.php # Storage backend contract
│   └── DiscountInterface.php   # Discount strategy contract
├── Storage/
│   ├── SessionStorage.php      # Session-based storage
│   ├── DatabaseStorage.php     # Database persistence
│   └── MemoryStorage.php       # In-memory storage (testing)
├── Models/
│   ├── CartItem.php            # Single cart item value object
│   ├── CartSummary.php         # Cart totals summary
│   └── CartTotals.php          # Extended totals with line items
├── Calculator/
│   ├── TaxCalculator.php       # Tax calculation strategies
│   ├── DiscountCalculator.php  # Discount calculation strategies
│   └── ShippingCalculator.php  # Shipping calculation strategies
├── Factory/
│   └── CartFactory.php         # Cart instance factory
├── Support/                    # Helper classes
├── ValueObjects/               # Additional value objects
├── Exceptions/                 # Custom exceptions
└── tests/
    └── CartTest.php            # PHPUnit test suite

Design Patterns Used

• Strategy Pattern - Tax, discount, and shipping calculators
• Factory Pattern - CartFactory for creating configured instances
• Repository Pattern - Storage abstraction for cart persistence
• Value Object - CartItem, CartSummary, CartTotals
• Dependency Injection - Inject storage and calculators

Running Tests

cd cart
composer install
vendor/bin/phpunit tests/

License

MIT License