<?php

namespace Drupal\DrupalExtension\Compiler;

use Symfony\Component\DependencyInjection\Reference,
    Symfony\Component\DependencyInjection\ContainerBuilder,
    Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface;

/**
 * Event subscribers pass - registers all available event subscribers.
 */
class EventSubscriberPass implements CompilerPassInterface {
  /**
   * Processes container.
   *
   * @param ContainerBuilder $container
   */
  public function process(ContainerBuilder $container) {
    if (!$container->hasDefinition('drupal.event_dispatcher')) {
      return;
    }
    $dispatcherDefinition = $container->getDefinition('drupal.event_dispatcher');

    foreach ($container->findTaggedServiceIds('drupal.event_subscriber') as $id => $attributes) {
      foreach ($attributes as $attribute) {
        $priority = isset($attribute['priority']) ? intval($attribute['priority']) : 0;
        $dispatcherDefinition->addMethodCall(
          'addSubscriber', array(new Reference($id), $priority)
        );
      }
    }
  }
}