AnnotatedClassDiscovery.php

<?php

namespace Drupal\rules\Context;

use Drupal\Component\Annotation\Doctrine\SimpleAnnotationReader;
use Drupal\Core\Plugin\Discovery\AnnotatedClassDiscovery as CoreAnnotatedClassDiscovery;

/**
 * Extends the annotation class discovery for usage with Rules context.
 *
 * We modify the annotations classes for ContextDefinition and for Condition.
 * This class makes sure that our plugin managers apply these.
 */
class AnnotatedClassDiscovery extends CoreAnnotatedClassDiscovery {
  
  /**
   * {@inheritdoc}
   */
  protected function getAnnotationReader() {
    if (!isset($this->annotationReader)) {
      // Do not call out the parent, but re-configure the simple annotation
      // reader on our own, so we can control the order of namespaces.
      $this->annotationReader = new SimpleAnnotationReader();
      // Make sure to add our namespace first, so our ContextDefinition and
      // Condition annotations gets picked.
      $this->annotationReader
        ->addNamespace('Drupal\\rules\\Context\\Annotation');
      $this->annotationReader
        ->addNamespace('Drupal\\rules\\Core\\Annotation');
      // Add the namespaces from the main plugin annotation, like @EntityType.
      $namespace = substr($this->pluginDefinitionAnnotationName, 0, strrpos($this->pluginDefinitionAnnotationName, '\\'));
      $this->annotationReader
        ->addNamespace($namespace);
      // Add general core annotations like @Translation.
      $this->annotationReader
        ->addNamespace('Drupal\\Core\\Annotation');
    }
    return $this->annotationReader;
  }

}