TestPrepareLayout.php

<?php

namespace Drupal\layout_builder_element_test\EventSubscriber;

use Drupal\Core\Messenger\MessengerInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\layout_builder\Event\PrepareLayoutEvent;
use Drupal\layout_builder\LayoutBuilderEvents;
use Drupal\layout_builder\LayoutTempstoreRepositoryInterface;
use Drupal\layout_builder\Section;
use Drupal\layout_builder\SectionComponent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Provides an event subscriber for testing section storage alteration.
 *
 * @see \Drupal\layout_builder\Event\PrepareLayoutEvent
 * @see \Drupal\layout_builder\Element\LayoutBuilder::prepareLayout()
 */
class TestPrepareLayout implements EventSubscriberInterface {
    use StringTranslationTrait;
    
    /**
     * The layout tempstore repository.
     *
     * @var \Drupal\layout_builder\LayoutTempstoreRepositoryInterface
     */
    protected $layoutTempstoreRepository;
    
    /**
     * The messenger service.
     *
     * @var \Drupal\Core\Messenger\MessengerInterface
     */
    protected $messenger;
    
    /**
     * Constructs a new TestPrepareLayout.
     *
     * @param \Drupal\layout_builder\LayoutTempstoreRepositoryInterface $layout_tempstore_repository
     *   The tempstore repository.
     * @param \Drupal\Core\Messenger\MessengerInterface $messenger
     *   The messenger service.
     */
    public function __construct(LayoutTempstoreRepositoryInterface $layout_tempstore_repository, MessengerInterface $messenger) {
        $this->layoutTempstoreRepository = $layout_tempstore_repository;
        $this->messenger = $messenger;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents() {
        // Act before core's layout builder subscriber.
        $events[LayoutBuilderEvents::PREPARE_LAYOUT][] = [
            'onBeforePrepareLayout',
            20,
        ];
        // Act after core's layout builder subscriber.
        $events[LayoutBuilderEvents::PREPARE_LAYOUT][] = [
            'onAfterPrepareLayout',
            -10,
        ];
        return $events;
    }
    
    /**
     * Subscriber to test acting before the LB subscriber.
     *
     * @param \Drupal\layout_builder\Event\PrepareLayoutEvent $event
     *   The prepare layout event.
     */
    public function onBeforePrepareLayout(PrepareLayoutEvent $event) {
        $section_storage = $event->getSectionStorage();
        $context = $section_storage->getContextValues();
        if (!empty($context['entity'])) {
            
            /** @var \Drupal\Core\Entity\EntityInterface $entity */
            $entity = $context['entity'];
            // Node 1 or 2: Append a block to the layout.
            if (in_array($entity->id(), [
                '1',
                '2',
            ])) {
                $section = new Section('layout_onecol');
                $section->appendComponent(new SectionComponent('fake-uuid', 'content', [
                    'id' => 'static_block',
                    'label' => 'Test static block title',
                    'label_display' => 'visible',
                    'provider' => 'fake_provider',
                ]));
                $section_storage->appendSection($section);
            }
            // Node 2: Stop event propagation.
            if ($entity->id() === '2') {
                $event->stopPropagation();
            }
        }
    }
    
    /**
     * Subscriber to test acting after the LB subscriber.
     *
     * @param \Drupal\layout_builder\Event\PrepareLayoutEvent $event
     *   The prepare layout event.
     */
    public function onAfterPrepareLayout(PrepareLayoutEvent $event) {
        $section_storage = $event->getSectionStorage();
        $context = $section_storage->getContextValues();
        if (!empty($context['entity'])) {
            
            /** @var \Drupal\Core\Entity\EntityInterface $entity */
            $entity = $context['entity'];
            // Node 1, 2, or 3: Append a block to the layout.
            if (in_array($entity->id(), [
                '1',
                '2',
                '3',
            ])) {
                $section = new Section('layout_onecol');
                $section->appendComponent(new SectionComponent('fake-uuid', 'content', [
                    'id' => 'static_block_two',
                    'label' => 'Test second static block title',
                    'label_display' => 'visible',
                    'provider' => 'fake_provider',
                ]));
                $section_storage->appendSection($section);
            }
        }
    }

}