carlosbuenosvinos/ddd

This library will help you with typical DDD scenarios, for now:

• Application Services Interface
• Transactional Application Services with Doctrine and ADODb
• Domain Event Interface
• Event Store Interface
• Event Store Doctrine Implementation
• Domain Event Publishing Service
• Messaging Producer Interface
• Messaging Producer RabbitMQ Implementation

Sample Projects

There are some projects developed using carlosbuenosvinos/ddd library. Check some of them to see how to use it:

• Last Wishes: Actions to run, such as tweet, send emails, etc. in case anything happen to you.

Application Services

Application Service Interface

Consider an Application Service that registers a new user in your application.

$signInUserService = new SignInUserService(
    $em->getRepository('MyBC\Domain\Model\User\User')
);

$response = $signInUserService->execute(
    new SignInUserRequest(
        'carlos.buenosvinos@gmail.com',
        'thisisnotasecretpassword'
    )
);

$newUserCreated = $response->getUser();
//...

We need to pass in the constructor all the dependencies. In this case, the User repository. As DDD explains, the Doctrine repository is implementing a generic interface for User repositories.

<?php

namespace MyBC\Application\Service\User;

use MyBC\Domain\Model\User\User;
use MyBC\Domain\Model\User\UserAlreadyExistsException;
use MyBC\Domain\Model\User\UserRepository;

use Ddd\Application\Service\ApplicationService;

/**
 * Class SignInUserService
 * @package MyBC\Application\Service\User
 */
class SignInUserService implements ApplicationService
{
    /**
     * @var UserRepository
     */
    private $userRepository;

    /**
     * @param UserRepository $userRepository
     */
    public function __construct(UserRepository $userRepository)
    {
        $this->userRepository = $userRepository;
    }

    /**
     * @param SignInUserRequest $request
     * @return SignInUserResponse
     * @throws UserAlreadyExistsException
     */
    public function execute($request = null)
    {
        $email = $request->email();
        $password = $request->password();

        $user = $this->userRepository->userOfEmail($email);
        if (null !== $user) {
            throw new UserAlreadyExistsException();
        }

        $user = new User(
            $this->userRepository->nextIdentity(),
            $email,
            $password
        );

        $this->userRepository->persist($user);

        return new SignInUserResponse($user);
    }
}

I suggest to make your Application Services implement the following interface following the command pattern.

/**
 * Interface ApplicationService
 * @package Ddd\Application\Service
 */
interface ApplicationService
{
    /**
     * @param $request
     * @return mixed
     */
    public function execute($request = null);
}

Transactions

Application Services should manage transactions when dealing with database persistence strategies. In order to manage it cleanly, I provide an Application Service decorator that wraps an Application Service an executes it inside a transactional boundary.

The decorator is the Ddd\Application\Service\TransactionalApplicationService class. In order to create one, you need the non transactional Application Service and a Transactional Session. We provide different types of Transactional Sessions. See how to do it with Doctrine.

Doctrine Transactional Application Services

For the Doctrine Transactional Session, pass the EntityManager instance.

/** @var EntityManager $em */
$txSignInUserService = new TransactionalApplicationService(
    new SignInUserService(
        $em->getRepository('MyBC\Domain\Model\User\User')
    ),
    new DoctrineSession($em)
);

$response = $txSignInUserService->execute(
    new SignInUserRequest(
        'carlos.buenosvinos@gmail.com',
        'thisisnotasecretpassword'
    )
);

$newUserCreated = $response->getUser();
//...

As you can see, the use case creation and execution is the same as the non transactional, the only difference is the decoration with the Transactional Application Service.

As a collateral benefit, the Doctrine Session manages internally the flush method, so you don't need to add a flush in your Domain neither your infrastructure.