Extending a base class with nested data objects

[booni3]

I have the following abstract base classes:

abstract class AbstractInvoiceDTO extends Data
{
    public AbstractContactDTO $contact;
}

abstract class AbstractContactDTO extends Data
{
    public string $name;
}

These are extended into:

class XeroInvoiceDTO extends AbstractInvoiceDTO
{
    public function __construct(
        #[MapInputName('Contact')]
        public AbstractContactDTO $contact,
    ) {}
}

class XeroContactDTO extends AbstractContactDTO
{
    public function __construct(
        #[MapInputName('Name')]
        public string $name,
    ) {}
}

With this setup, the Contact data is passed through the AbstractContactDTO and therefore does not work. We need to be passing it through the XeroContactDTO but we are unable to overwrite the property type, with the error:

Type of Domain\Invoice\Services\Xero\XeroInvoiceDTO::$contact must be Domain\Invoice\Services\AbstractContactDTO (as in class Domain\Invoice\Services\AbstractInvoiceDTO)

Are there any workarounds for this within the package?

[booni3]

So I found a couple ways to do this:

class XeroInvoiceDTO extends AbstractInvoiceDTO
{
    public function __construct(
        #[MapInputName('Contact')]
        public $contact,
    ) {
        $this->contact = XeroContactDTO::from($this->contact);
    }

Or

class XeroInvoiceDTO extends AbstractInvoiceDTO
{
    public function __construct(
        #[MapInputName('Contact'), WithCast(FromDataCaster::class, class: XeroContactDTO::class)]
        public $contact,
    ) {
        
    }

With the FromDataCaster looking like this (probably a better name for it!)

class FromDataCaster implements Cast
{
    protected $class;

    public function __construct($class)
    {
        $this->class = $class;
    }

    public function cast(DataProperty $property, mixed $value, array $context): mixed
    {
        return $this->class::from($value);
    }
}

I am surprised that this kind of caster does not already exist within the package unless I have missed it. I looked through catsers and transformers and could not find something suitable.

[booni3]

I see this is not what this package is designed for. Closing as irrelevant in this context.