YamlDiscovery.php

<?php

/**
 * @file
 * Contains Drupal\Core\Plugin\Discovery\YamlDiscovery.
 */

namespace Drupal\Core\Plugin\Discovery;

use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
use Drupal\Component\Discovery\YamlDiscovery as DrupalYamlDiscovery;
use Drupal\Core\Extension\ModuleHandlerInterface;

/**
 * Allows Yaml files to discover plugin definitions.
 *
 * @todo there should be a base class provided so every YAML file doesn't have to specify the implementation.
 */
class YamlDiscovery implements DiscoveryInterface {

  /**
   * Internal YAML parsing handler.
   *
   * @var \Drupal\Component\Discovery\YamlDiscovery
   */
  protected $discovery;

  /**
   * The extension handler for retrieving the list of enabled modules.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface
   */
  protected $moduleHandler;

  /**
   * Construct a YamlDiscovery object.
   *
   * @param string $name
   *   The
   * @param ModuleHandlerInterface $module_handler
   *   The module handler service.
   */
  function __construct($name, ModuleHandlerInterface $module_handler) {
    $this->moduleHandler = $module_handler;
    $this->discovery = new DrupalYamlDiscovery($name, $this->moduleHandler->getModuleDirectories());
  }

  /**
   * {@inheritdoc}
   */
  public function getDefinition($plugin_id) {
    $plugins = $this->getDefinitions();
    return isset($plugins[$plugin_id]) ? $plugins[$plugin_id] : NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function getDefinitions() {
    return $this->discovery->findAll();
  }
}