Separate the domain model and persistence layer

[mohammadhsn]

Hi,

I have a design-related question, As I know about DDD and some sources I read, most people indicate separations between domain and persistence (or infrastructure in general). Most people use Doctrine ORM when they consider the DDD approach in PHP, domain models (or Entities) are a part of domain, so they have no idea about persistence.

Let's imagine we have an Author domain model that publishes posts, I thought below code:

class Post
{
    public function __construct(
        protected Author $author,
        protected PostTitle $title,
        protected PostContent $content,
        protected DateTimeImmutable $publishedAt
    ) {}
}

class Author
{
    public function __construct(
        protected AuthorEmail $email,
        protected array $posts = []
    ) {}

    public function publishNewPost(Post $post)
    {
        $this->posts []= $posts;
    }
}

I fact, what I want is I could use the Post and Author classes as domain models and also as doctrine entities.
The problem is doctrine forces me to use ArrayCollection instead of array so the domain has to know about persistence. I'm looking for a design solution that separates all domain model concerns from doctrine concerns.

[beberlei]

@mohammadhsn that is not going to be possible 100%, due to other concerns such as lazy loading. but ArrayCollection is also its own library so you could consider it independent from Persistence.