Immutable Value Objects in PHP and Laravel With the Bags Package

Bag is a PHP and Laravel package for Immutable Value Objects, inspired by Spatie's laravel-data package. It can help you create immutable objects to encapsulate your data in a type-safe way with data casts and built-in validation. The package suggests it can be used to replace regular arrays in your code to benefit from type safety.

use Bag\Bag;

readonly class MyValue extends Bag {
    public function __construct(public string $name, public int $age) {}
}

$value = MyValue::from([
    'name' => 'Davey Shafik',
    'age' => 40,
]);

// Create a new instance with a different value
$newValue = $value->with(age: 41);

Bag also has an integration with Laravel, using standard Collection and Validation in value objects, as well as Eloquent casts and the ability to inject Bag objects into controllers with validation:

use Bag\Attributes\Laravel\FromRouteParameter;
use Bag\Bag;

class MyValue extends Bag
{
    #[FromRouteParameter()]
    public string $id;
}

// MyValue $value will have the populated `id` route parameter
class MyController extends Controller {
    public function store(MyValue $value) {
        // $value is a validated MyValue object
    }
}