Patrón de capa de servicio en XOOPS

2.5.x ✅ 4.0.x ✅

El patrón de capa de servicio funciona tanto en XOOPS 2.5.x como en XOOPS 4.0.x. Los conceptos son universales, solo la sintaxis difiere:

Característica	XOOPS 2.5.x	XOOPS 4.0
Versión PHP	7.4+	8.2+
Inyección de constructor	✅ Cableado manual	✅ Cableado automático del contenedor
Propiedades tipificadas	Bloques de documentación `@var`	Declaraciones de tipo nativo
Propiedades de solo lectura	❌ No disponible	✅ Palabra clave `readonly`

Los ejemplos de código a continuación utilizan sintaxis PHP 8.2+. Para 2.5.x, omita readonly y use declaraciones de propiedad tradicionales.

El patrón de capa de servicio encapsula la lógica empresarial en clases de servicio dedicadas, proporcionando una separación clara entre controladores y capas de acceso a datos. Este patrón promueve la reutilización del código, la verificabilidad y la mantenibilidad.

Service Layer Concept

Purpose

The Service Layer:

Contains domain business logic
Coordinates multiple repositories
Handles complex operations
Manages transactions
Performs validation and authorization
Provides high-level operations to controllers

Benefits

Reusable business logic across multiple controllers
Easy to test in isolation
Centralized business rule implementation
Clear separation of concerns
Simplified controller code

Dependency Injection

<?php
// Service with injected dependencies
class UserService
{
    private $userRepository;
    private $emailService;

    public function __construct(
        UserRepositoryInterface $userRepository,
        EmailServiceInterface $emailService
    ) {
        $this->userRepository = $userRepository;
        $this->emailService = $emailService;
    }

    public function registerUser($username, $email, $password)
    {
        // Validate
        $this->validate($username, $email, $password);

        // Create user
        $user = new User();
        $user->setUsername($username);
        $user->setEmail($email);
        $user->setPassword($password);

        // Save
        $userId = $this->userRepository->save($user);

        // Send welcome email
        $this->emailService->sendWelcome($email, $username);

        return $userId;
    }

    private function validate($username, $email, $password)
    {
        $errors = [];

        if (strlen($username) < 3) {
            $errors['username'] = 'Username too short';
        }

        if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
            $errors['email'] = 'Invalid email';
        }

        if (strlen($password) < 6) {
            $errors['password'] = 'Password too short';
        }

        if (!empty($errors)) {
            throw new ValidationException('Invalid input', $errors);
        }
    }
}
?>

Service Container

<?php
class ServiceContainer
{
    private $services = [];

    public function __construct($db)
    {
        // Register repositories
        $this->services['userRepository'] = new UserRepository($db);

        // Register services
        $this->services['userService'] = new UserService(
            $this->services['userRepository']
        );
    }

    public function get($name)
    {
        if (!isset($this->services[$name])) {
            throw new \InvalidArgumentException("Service not found: $name");
        }
        return $this->services[$name];
    }
}
?>

Usage in Controllers

<?php
class UserController
{
    private $userService;

    public function __construct(ServiceContainer $container)
    {
        $this->userService = $container->get('userService');
    }

    public function registerAction()
    {
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            return [];
        }

        try {
            $userId = $this->userService->registerUser(
                $_POST['username'],
                $_POST['email'],
                $_POST['password']
            );

            return [
                'success' => true,
                'userId' => $userId,
            ];
        } catch (ValidationException $e) {
            return [
                'success' => false,
                'errors' => $e->getErrors(),
            ];
        }
    }
}
?>

Best Practices

Each service handles one domain concern
Services depend on interfaces, not implementations
Use constructor injection for dependencies
Services should be testable in isolation
Throw domain-specific exceptions
Services should not depend on HTTP request details
Keep services focused and cohesive