datafield-1.x-dev/src/Plugin/DataField/FieldFormatter/EntityReferenceLabelFormatter.php

<?php

namespace Drupal\datafield\Plugin\DataField\FieldFormatter;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Field\Attribute\FieldFormatter;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\datafield\Plugin\DataFieldFormatterInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Plugin implementation of the 'entity reference label' formatter.
 */
#[FieldFormatter(
  id: 'entity_reference_label',
  label: new TranslatableMarkup('Label'),
  description: new TranslatableMarkup('Display the label of the referenced entities.'),
  field_types: ['entity_reference'],
)]
class EntityReferenceLabelFormatter implements DataFieldFormatterInterface, ContainerFactoryPluginInterface {
  use StringTranslationTrait;

  /**
   * Constructs a UrlPlainFormatter object.
   *
   *   The plugin implementation definition.
   *
   * @param string $plugin_id
   *   The plugin_id for the formatter.
   * @param mixed $plugin_definition
   *   The plugin implementation definition.
   * @param mixed $field_definition
   *   The definition of the field to which the formatter is associated.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
   *   The entity type manager.
   */
  public function __construct($plugin_id, $plugin_definition, $field_definition, protected EntityTypeManagerInterface $entityTypeManager) {
    unset($plugin_id, $plugin_definition, $field_definition);
  }

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

  /**
   * {@inheritdoc}
   */
  public static function defaultSettings() {
    return [
      'link' => TRUE,
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function settingsForm(array $form, FormStateInterface $form_state) {
    $settings = $form['#settings'];
    $elements['link'] = [
      '#title' => $this->t('Link label to the referenced entity'),
      '#type' => 'checkbox',
      '#default_value' => $settings['link'] ?? TRUE,
    ];

    return $elements;
  }

  /**
   * {@inheritdoc}
   */
  public function settingsSummary($settings = []) {
    $summary = [];
    $summary[] = !empty($settings['link']) ? $this->t('Link to the referenced entity') : $this->t('No link');
    return $summary;
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements($item, $langcode) {
    if (empty($item->value)) {
      return $item->value;
    }
    $explode = explode(':', $item->field_setting["entity_reference_type"]);
    $reference_type = end($explode);
    $entity = $item->value;
    if (!empty($item->field_setting["target_bundles"]) && $item->field_setting["target_bundles"] == 'file') {
      $reference_type = 'file';
    }
    if (is_numeric($entity)) {
      $entity = $this->entityTypeManager->getStorage($reference_type)
        ->load($entity);
    }
    if (empty($entity)) {
      return '';
    }
    $label_field = $entity->getEntityType()->getKey('label');
    $title = $label_field ? $entity->get($label_field)?->value : '';
    if (empty($title) && method_exists($entity, 'getDisplayName')) {
      $title = $entity->getDisplayName();
    }
    if (!empty($item->settings["link"]) && $entity->hasLinkTemplate('canonical')) {
      return [
        '#type' => 'link',
        '#langcode' => $langcode,
        '#title' => $title,
        '#url' => $entity->toUrl(),
        '#cache' => ['tags' => $entity->getCacheTags()],
      ];
    }
    else {
      return [
        '#plain_text' => $title,
        '#langcode' => $langcode,
        '#cache' => ['tags' => $entity->getCacheTags()],
      ];
    }
  }

}