improvements-2.x-dev/src/Plugin/Field/FieldFormatter/EntityHtmlAttributeFormatter.php

<?php

namespace Drupal\improvements\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Field\FormatterBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Markup;
use Drupal\druhels\EntityHelper;

/**
 * @FieldFormatter(
 *   id = "entity_html_attribute_formatter",
 *   label = @Translation("Entity html attribute"),
 *   field_types = {
 *     "string",
 *     "integer",
 *     "list_string",
 *   },
 * )
 */
class EntityHtmlAttributeFormatter extends FormatterBase {

  /**
   * {@inheritdoc}
   */
  public static function defaultSettings(): array {
    $options = parent::defaultSettings();

    $options['attribute_name'] = 'class';
    $options['attribute_value_pattern'] = '';

    return $options;
  }

  /**
   * {@inheritdoc}
   */
  public function settingsForm(array $form, FormStateInterface $form_state): array {
    $form = parent::settingsForm($form, $form_state);

    $form['attribute_name'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Attribute name'),
      '#default_value' => $this->getSetting('attribute_name'),
    ];

    $form['attribute_value_pattern'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Attribute value pattern'),
      '#description' => $this->t('Example: @example', ['@example' => Markup::create('<code>grid-columns-@value</code>')]),
      '#default_value' => $this->getSetting('attribute_value_pattern'),
    ];

    return $form;
  }

  /**
   * {@inheritDoc}
   */
  public function settingsSummary(): array {
    $summary = [];

    if ($attribute_name = $this->getSetting('attribute_name')) {
      $summary[] = $this->t('Attribute name') . ': ' . $attribute_name;
    }
    if ($attribute_value_pattern = $this->getSetting('attribute_value_pattern')) {
      $summary[] = $this->t('Attribute value pattern') . ': ' . $attribute_value_pattern;
    }

    return $summary;
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode): array {
    $build = [];
    $formatter_settings = $this->getSettings();
    $attribute_name = $formatter_settings['attribute_name'];
    $items_values = EntityHelper::getFieldValues($items);

    foreach ($items_values as $item_value) {
      $attribute_value = str_replace('@value', $item_value, $formatter_settings['attribute_value_pattern']);

      if ($attribute_name == 'class') {
        $build['#entity_attributes'][$attribute_name][] = $attribute_value;
      }
      else {
        $build['#entity_attributes'][$attribute_name] = $attribute_value;
      }
    }

    return $build;
  }

}