improvements-2.x-dev/modules/improvements_views/src/Plugin/Field/FieldType/ViewsItem.php

<?php

namespace Drupal\improvements_views\Plugin\Field\FieldType;

use Drupal\Core\Field\FieldItemBase;
use Drupal\Core\Field\FieldStorageDefinitionInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\TypedData\DataDefinition;

/**
 * @FieldType(
 *   id = "views",
 *   label = @Translation("Views"),
 *   description = @Translation("Field for storing data about Views (View id and display name)."),
 *   default_widget = "views_widget",
 *   default_formatter = "views_formatter",
 * )
 */
class ViewsItem extends FieldItemBase {

  /**
   * {@inheritDoc}
   */
  public static function schema(FieldStorageDefinitionInterface $field_definition): array {
    return [
      'columns' => [
        'value' => [
          'type' => 'varchar',
          'length' => 255,
          'description' => 'View id and display name',
        ],
      ],
    ];
  }

  /**
   * {@inheritDoc}
   */
  public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition): array {
    $properties['value'] = DataDefinition::create('string')
      ->setLabel(new TranslatableMarkup('View id and display name'))
      ->setRequired(TRUE);

    return $properties;
  }

}