islandora/src/ContextReaction/DisplayAlterReaction.php

<?php

namespace Drupal\islandora\ContextReaction;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\context\ContextReactionPluginBase;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Base context reaction to alter view/form mode.
 */
abstract class DisplayAlterReaction extends ContextReactionPluginBase implements ContainerFactoryPluginInterface {

  const MODE = 'mode';

  /**
   * View mode storage.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;

  /**
   * {@inheritdoc}
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->entityTypeManager = $entity_type_manager;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
    return new static(
      $configuration,
      $plugin_id,
      $plugin_definition,
      $container->get('entity_type.manager')
    );
  }

  /**
   * {@inheritdoc}
   */
  public function execute() {
    // Return the mode name by itself.
    $config = $this->getConfiguration();
    $exploded = explode('.', $config[self::MODE]);
    return $exploded[1];
  }

  /**
   * {@inheritdoc}
   */
  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
    $this->setConfiguration([self::MODE => $form_state->getValue(self::MODE)]);
  }

}