for testing and deploying your application
for finding and fixing issues
for empowering human code reviews
<?php
declare(strict_types=1);
namespace Yiisoft\Definitions;
use Psr\Container\ContainerInterface;
use Yiisoft\Definitions\Contract\ReferenceInterface;
use Yiisoft\Definitions\Exception\InvalidConfigException;
use function is_string;
/**
* The `Reference` defines a dependency to a service in the container or factory in another service definition.
* For example:
*
* ```php
* [
* InterfaceA::class => ConcreteA::class,
* 'alternativeForA' => ConcreteB::class,
* MyService::class => [
* '__construct()' => [
* Reference::to('alternativeForA'),
* ],
* ]
* ```
*/
final class Reference implements ReferenceInterface
{
private string $id;
private bool $optional;
* @param mixed $id
* @throws InvalidConfigException
private function __construct($id, bool $optional)
if (!is_string($id)) {
throw new InvalidConfigException('Reference ID must be string.');
}
$this->id = $id;
$this->optional = $optional;
* @throws InvalidConfigException If ID is not string.
public static function to($id): self
return new self($id, false);
* Optional reference returns `null` when there is no corresponding definition in container.
* @param mixed $id ID of the service or object to point to.
public static function optional($id): self
return new self($id, true);
public function resolve(ContainerInterface $container)
return (!$this->optional || $container->has($this->id)) ? $container->get($this->id) : null;
yiisoft /
definitions
