Cart Promotions

Cart promotions package for Basketin — discount rules, coupons and a promotion engine for Laravel e-commerce.

Installation

composer require basketin/cart-promotions

The service provider is auto-discovered by Laravel.

Usage

Creating a Promotion Rule

Create a class that extends Promotion and implements PromotionRule:

use Obelaw\Basketin\Cart\Promotions\Contracts\PromotionRule;
use Obelaw\Basketin\Cart\Promotions\Promotion;
use Obelaw\Basketin\Cart\Services\CartService;

class MyPromoRule extends Promotion implements PromotionRule
{
    protected ?string $name = 'My Promotion';

    public function calculate(CartService $cart): float
    {
        // Return the discount amount
        return 100;
    }
}

Applying Promotions

Use the promotions() macro on the totals service:

$cart = CartManagement::make('cart_id', 'USD');
$cart->quote()->addQuote($product, 1);

$totals = $cart->totals();

$totals->promotions()
    ->rule(new MyPromoRule())
    ->apply();

$discountedTotal = $totals->getGrandTotal();

Multiple Rules

You can chain multiple rules:

$totals->promotions()
    ->rule(new RuleOne())
    ->rule(new RuleTwo())
    ->apply();

Getting Applied Rules

After applying promotions, you can retrieve the applied rules:

$totals->promotions()
    ->rule(new MyPromoRule())
    ->apply();

$appliedRules = $totals->promotions()->getAppliedRules();
// Returns array of applied rules with name, discount_amount, and rule_type

Architecture

PromotionEngine

Main class that processes promotion rules against a cart.

Methods:

• rule(PromotionRule $rule) - Add a promotion rule
• apply() - Apply all rules and calculate discounts
• getAppliedRules() - Get list of applied rules with details

Promotion (Abstract Class)

Base class for promotions. Provides getName() method.

PromotionRule (Interface)

Contract for promotion rules. Requires:

• getName(): string - Return the promotion name
• calculate(CartService $cart): float - Calculate discount amount