ExifReadonlyWidget.php

<?php

namespace Drupal\exif\Plugin\Field\FieldWidget;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Plugin implementation of the 'exif_readonly' widget.
 *
 * @FieldWidget(
 *   id = "exif_readonly",
 *   label = @Translation("metadata from image (viewable in forms)"),
 *   description = @Translation("field content is calculated from image field
 *   in the same content type (field are viewable but readonly in forms)"),
 *   multiple_values = true, field_types = {
 *     "string",
 *     "string_long",
 *     "text",
 *     "text_with_summary",
 *     "text_long",
 *     "entity_reference",
 *     "date",
 *     "datetime",
 *     "datestamp"
 *   }
 * )
 */
class ExifReadonlyWidget extends ExifFieldWidgetBase implements ContainerFactoryPluginInterface {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Constructs a ExifReadonlyWidget object.
     *
     * @param string $plugin_id
     *   The plugin_id for the widget.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
     *   The definition of the field to which the widget is associated.
     * @param array $settings
     *   The widget settings.
     * @param array $third_party_settings
     *   Any third party settings.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, array $third_party_settings, EntityTypeManagerInterface $entity_type_manager) {
        parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $third_party_settings);
        $this->entityTypeManager = $entity_type_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($plugin_id, $plugin_definition, $configuration['field_definition'], $configuration['settings'], $configuration['third_party_settings'], $container->get('entity_type.manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
        $value = $items->getValue();
        $entity_type = $items->getFieldDefinition()
            ->getTargetEntityTypeId();
        $access = $this->entityTypeManager
            ->getAccessControlHandler($entity_type)
            ->fieldAccess('view', $items->getFieldDefinition());
        if (!$access) {
            $element += [
                '#type' => '#hidden',
                '#value' => '',
            ];
        }
        $element += $items->view();
        $element += [
            '#value' => $value,
            '#default_value' => $value,
        ];
        return $element;
    }

}