improvements-2.x-dev/src/Plugin/Field/FieldFormatter/TextReplaceFormatter.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\improvements\ImprovementsHelper;

/**
 * @FieldFormatter(
 *   id = "text_replace",
 *   label = @Translation("Template by RegExp"),
 *   field_types = {
 *     "text",
 *     "text_long",
 *     "text_with_summary",
 *     "string",
 *   },
 * )
 */
class TextReplaceFormatter extends FormatterBase {

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

  /**
   * {@inheritdoc}
   */
  public function settingsForm(array $form, FormStateInterface $form_state): array {
    $elements['regexp'] = [
      '#type' => 'textfield',
      '#title' => t('RegExp pattern'),
      '#default_value' => $this->getSetting('regexp'),
      '#description' => $this->t('Example: @example', ['@example' => Markup::create('<code>/(.+): (.+)/</code>')]),
      '#attributes' => [
        'style' => 'font-family:monospace;',
      ],
    ];

    $elements['template'] = [
      '#type' => 'textarea',
      '#title' => t('Template'),
      '#default_value' => $this->getSetting('template'),
      '#description' => $this->t('Example: @example', ['@example' => Markup::create('<code>' . htmlspecialchars('<b>$1</b>: $2') . '</code>')]),
      '#rows' => ImprovementsHelper::getTextareaRowsCount($this->getSetting('template'), 1),
    ];

    return $elements;
  }

  /**
   * {@inheritdoc}
   */
  public function viewElements(FieldItemListInterface $items, $langcode): array {
    $elements = [];

    foreach ($items as $delta => $item) {
      $elements[$delta] = $this->viewElement($item);
    }

    return $elements;
  }

  /**
   * Return element build.
   */
  public function viewElement($item): array {
    $settings = $this->getSettings();
    $text = preg_replace($settings['regexp'], $settings['template'], $item->value);

    if (in_array($this->fieldDefinition->getType(), ['text', 'text_long', 'text_with_summary'])) {
      return [
        '#type' => 'processed_text',
        '#text' => $text,
        '#format' => $item->format,
        '#langcode' => $item->getLangcode(),
      ];
    }

    return [
      '#markup' => $text,
    ];
  }

}