#[DataCollection]

Declares that a property holds a typed collection of another BaseData class. The property type must be TypedDataCollection.

Syntax

use StdOut\SimpleDataObjects\Attributes\DataCollection;
use StdOut\SimpleDataObjects\TypedDataCollection;

#[DataCollection(ItemData::class)]
public readonly TypedDataCollection $items,

The target class is validated when metadata is built: it must exist and be a data object (extend BaseData), otherwise a DataHydrationException is thrown immediately instead of failing later at runtime.

Example

class InvoiceData extends BaseData
{
    public function __construct(
        public readonly string            $number,
        #[DataCollection(LineItemData::class)]
        public readonly TypedDataCollection $lines,
    ) {}
}

$invoice = InvoiceData::from([
    'number' => 'INV-001',
    'lines'  => [
        ['description' => 'Widget', 'quantity' => 2, 'price' => 9.99],
        ['description' => 'Gadget', 'quantity' => 1, 'price' => 49.00],
    ],
]);

$invoice->lines->count();              // 2
$invoice->lines->first()->description; // 'Widget'

Serialization

$invoice->toArray();
// [
//   'number' => 'INV-001',
//   'lines'  => [
//     ['description' => 'Widget', 'quantity' => 2, 'price' => 9.99],
//     ['description' => 'Gadget', 'quantity' => 1, 'price' => 49.00],
//   ],
// ]

Constraints

Cannot combine with #[Cast] or #[Flatten] on the same parameter.

See Also

• Collections feature →
• TypedDataCollection generics →