Provide a ModelInterface and ModelTrait for Eloquent to support Hexagonal Architecture

[alexander-schranz]

In cases like hexagonal architecture you want to separate the infrastructure code from the domain logic. So you have example a:

namespace App\Domain\Model;

class Example {
    private $id;

    private $title;

    public function __construct()
    {
         $this->title = 'Undefined';
    }

    public function getTitle(): string
    {
         return $this->title;
    }
    
    public function setTitle($title): void
    {
         $this->title = $title;
    }
}

And want to have a laravel integration for eloquent for it with:

namespace App\Infrastructure\Laravel\Eloquent;

use Illuminate\Database\Eloquent\Mode.Interface;
use Illuminate\Database\Eloquent\ModelTrait;

class Example extends DomainExample implements ModelInterface {
    use ModelTrait;
}

Which adds eloquent methods to the model. The hardest thing which I did fail to implement such a thing was some static variables and how static variables behave differently between traits and abstract classes. Global config for all entities would need to be stored in a global class object and can not be in the trait as static variable.