InfoHookDecorator.php

<?php

namespace Drupal\Core\Plugin\Discovery;

use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
use Drupal\Component\Plugin\Discovery\DiscoveryTrait;

/**
 * Allows info hook implementations to enhance discovered plugin definitions.
 */
class InfoHookDecorator implements DiscoveryInterface {
    use DiscoveryTrait;
    
    /**
     * The Discovery object being decorated.
     *
     * @var \Drupal\Component\Plugin\Discovery\DiscoveryInterface
     */
    protected $decorated;
    
    /**
     * The name of the info hook that will be implemented by this discovery instance.
     *
     * @var string
     */
    protected $hook;
    
    /**
     * Constructs a InfoHookDecorator object.
     *
     * @param \Drupal\Component\Plugin\Discovery\DiscoveryInterface $decorated
     *   The object implementing DiscoveryInterface that is being decorated.
     * @param string $hook
     *   The name of the info hook to be invoked by this discovery instance.
     */
    public function __construct(DiscoveryInterface $decorated, $hook) {
        $this->decorated = $decorated;
        $this->hook = $hook;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefinitions() {
        $definitions = $this->decorated
            ->getDefinitions();
        foreach (\Drupal::moduleHandler()->getImplementations($this->hook) as $module) {
            $function = $module . '_' . $this->hook;
            $function($definitions);
        }
        return $definitions;
    }
    
    /**
     * Passes through all unknown calls onto the decorated object.
     */
    public function __call($method, $args) {
        return call_user_func_array([
            $this->decorated,
            $method,
        ], $args);
    }

}