final class ExamplePreprocessEventSubscriber in Hook Event Dispatcher 8.2

Class ExamplePreprocessorEventSubscriber.

Don't forget to define your class as a service and tag it as an "event_subscriber":

services: hook_event_dispatcher.example_preprocess_subscribers: class: Drupal\hook_event_dispatcher\ExamplePreprocessEventSubscribers tags:

• { name: event_subscriber }

Hierarchy

• class \Drupal\hook_event_dispatcher\ExamplePreprocessEventSubscriber implements \Symfony\Component\EventDispatcher\EventSubscriberInterface

File

examples/ExamplePreprocessEventSubscriber.php, line 22

Namespace

Drupal\hook_event_dispatcher

final class ExamplePreprocessEventSubscriber implements EventSubscriberInterface {

  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() : array {
    return [
      NodePreprocessEvent::name('article', 'full') => 'preprocessArticleFull',
      PagePreprocessEvent::name() => 'preprocessPage',
      BlockPreprocessEvent::name() => 'preprocessBlock',
    ];
  }

  /**
   * Preprocess a node with bundle type article in view mode full.
   *
   * @param \Drupal\preprocess_event_dispatcher\Event\NodePreprocessEvent $event
   *   Event.
   */
  public function preprocessArticleFull(NodePreprocessEvent $event) : void {

    /** @var \Drupal\preprocess_event_dispatcher\Variables\NodeEventVariables $variables */
    $variables = $event
      ->getVariables();
    $node = $variables
      ->getNode();
    $someField = $node
      ->get('field_some_field')
      ->view();
    $variables
      ->set('some_field', $someField);
  }

  /**
   * Preprocess a node page to set the node title as page title.
   *
   * @param \Drupal\preprocess_event_dispatcher\Event\PagePreprocessEvent $event
   *   Event.
   */
  public function preprocessPage(PagePreprocessEvent $event) : void {

    /** @var \Drupal\preprocess_event_dispatcher\Variables\PageEventVariables $variables */
    $variables = $event
      ->getVariables();
    $node = $variables
      ->getNode();
    if ($node === NULL) {
      return;
    }
    $variables
      ->set('title', $node
      ->getTitle());
  }

  /**
   * Preprocess blocks with field_contact_form and add contact-form-wrapper id.
   *
   * @param \Drupal\preprocess_event_dispatcher\Event\BlockPreprocessEvent $event
   *   Event.
   */
  public function preprocessBlock(BlockPreprocessEvent $event) : void {

    /** @var \Drupal\preprocess_event_dispatcher\Variables\BlockEventVariables $variables */
    $variables = $event
      ->getVariables();
    if ($variables
      ->get('field_contact_form') === NULL) {
      return;
    }
    $variables
      ->getByReference('attributes')['id'] = 'contact-form-wrapper';
  }

}

Members

Name	Modifiers	Type	Description	Overrides
ExamplePreprocessEventSubscriber::getSubscribedEvents	public static	function	Returns an array of event names this subscriber wants to listen to.
ExamplePreprocessEventSubscriber::preprocessArticleFull	public	function	Preprocess a node with bundle type article in view mode full.
ExamplePreprocessEventSubscriber::preprocessBlock	public	function	Preprocess blocks with field_contact_form and add contact-form-wrapper id.
ExamplePreprocessEventSubscriber::preprocessPage	public	function	Preprocess a node page to set the node title as page title.