04.custom-platform.php

<?php

declare(strict_types=1);

use TypeLang\Mapper\Mapper;
use TypeLang\Mapper\Mapping\Provider\MetadataBuilder;
use TypeLang\Mapper\Mapping\Reader\AttributeReader;
use TypeLang\Mapper\Platform\Common\SupportsClassInstantiator;
use TypeLang\Mapper\Platform\Common\SupportsMetadata;
use TypeLang\Mapper\Platform\Common\SupportsPropertyAccessor;
use TypeLang\Mapper\Platform\GrammarFeature;
use TypeLang\Mapper\Platform\PlatformInterface;
use TypeLang\Mapper\Type\Builder\ClassTypeBuilder;

require __DIR__ . '/../../vendor/autoload.php';

// The set of types and grammar is defined using a "platform". You can create
// your own platform, for example, for a specific DB, or use built-in ones.
//
// For example, let's create a platform that supports only simple types,
// without generics, union types, shapes, and other things.

class SimplePlatform implements PlatformInterface
{
    use SupportsMetadata;
    use SupportsPropertyAccessor;
    use SupportsClassInstantiator;

    public function getName(): string
    {
        return 'simple';
    }

    public function getTypes(): iterable
    {
        $driver = new MetadataBuilder(new AttributeReader());

        // The platform will only support objects, that is,
        // references to existing classes.
        yield new ClassTypeBuilder(
            meta: $this->getMetadataProvider(),
            accessor: $this->getPropertyAccessor(),
            instantiator: $this->getClassInstantiator(),
        );
    }

    public function getTypeCoercers(): iterable
    {
        return [];
    }

    public function isFeatureSupported(GrammarFeature $feature): bool
    {
        // Disable all grammar features except the main one.
        return false;
    }
}

class ExampleDTO
{
    public function __construct(
        public readonly int $value = 42,
    ) {}
}

$mapper = new Mapper(new SimplePlatform());

try {
    var_dump($mapper->normalize(new ExampleDTO()));
} catch (\Throwable $e) {
    echo $e->getMessage() . "\n";
}
//
// TypeRequiredException: Type "int" for property ExampleDTO::$value
//                        is not defined
//

try {
    var_dump($mapper->normalize([new ExampleDTO()], 'array<ExampleDTO>'));
} catch (\Throwable $e) {
    echo $e->getMessage() . "\n";
}
//
// ParseException: Template arguments not allowed in "array<ExampleDTO>"
//                 at column 6
//