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

<?php

namespace Drupal\improvements\Plugin\Field\FieldFormatter;

use Drupal\Core\Field\Attribute\FieldFormatter;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Field\FormatterBase;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Template\AttributeHelper;
use Drupal\Core\Url;
use Drupal\druhels\ArrayHelper;
use Drupal\link\LinkItemInterface;

#[FieldFormatter(
  id: 'link_custom_text',
  label: new TranslatableMarkup('Link with custom text'),
  field_types: ['link'],
)]
class LinkCustomTextFormatter extends FormatterBase {

  /**
   * {@inheritdoc}
   */
  public static function defaultSettings(): array {
    return [
      'text' => '',
      'attributes' => [],
    ] + parent::defaultSettings();
  }

  /**
   * {@inheritdoc}
   */
  public function settingsForm(array $form, FormStateInterface $form_state): array {
    $formatter_settings = $this->getSettings();

    $elements['text'] = [
      '#type' => 'textfield',
      '#title' => t('Link text'),
      '#default_value' => $formatter_settings['text'],
    ];

    $elements['attributes'] = [
      '#type' => 'textarea',
      '#title' => $this->t('HTML attributes'),
      '#description' => t('Format') . ': <code>attribute-name: attribute-value</code>',
      '#rows' => 2,
      '#default_value' => ArrayHelper::formatArrayAsKeyValueList($formatter_settings['attributes']),
      '#element_validate' => [[$this, 'settingsFormPreprocessAttributes']],
    ];

    return $elements;
  }

  /**
   * #element_validate callback for 'attributes' element.
   */
  public function settingsFormPreprocessAttributes(array $element, FormStateInterface $form_state): void {
    $value = $form_state->getValue($element['#parents']);
    $value = ArrayHelper::formatKeyValueListAsArray($value, ': ');
    $form_state->setValueForElement($element, $value);
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode): array {
    $element = [];
    $formatter_settings = $this->getSettings();

    /** @var LinkItemInterface $item */
    foreach ($items as $delta => $item) {
      try {
        $url = $item->getUrl();
      }
      catch (\InvalidArgumentException $e) {
        $url = Url::fromRoute('<none>');
      }

      $element[$delta] = [
        '#type' => 'link',
        '#title' => $formatter_settings['text'],
        '#url' => $url,
        '#attributes' => ArrayHelper::formatArrayAsAttributes($formatter_settings['attributes']),
      ];

      if (!empty($item->_attributes)) {
        $element[$delta]['#attributes'] = AttributeHelper::mergeCollections($element[$delta]['#attributes'], $item->_attributes);
        // Unset field item attributes since they have been included in the
        // formatter output and should not be rendered in the field template.
        unset($item->_attributes);
      }
    }

    return $element;
  }

}