class Icon

class Icon extends RenderElementBase {
  
  /**
   * {@inheritdoc}
   */
  public function getInfo() : array {
    return [
      '#pre_render' => [
        [
          self::class,
          'preRenderIcon',
        ],
      ],
      '#pack_id' => '',
      '#icon_id' => '',
      '#settings' => [],
    ];
  }
  
  /**
   * Icon element pre render callback.
   *
   * @param array $element
   *   An associative array containing the properties of the icon element.
   *
   * @return array
   *   The modified element.
   */
  public static function preRenderIcon(array $element) : array {
    $icon_full_id = IconDefinition::createIconId($element['#pack_id'], $element['#icon_id']);
    $pluginManagerIconPack = \Drupal::service('plugin.manager.icon_pack');
    if (!($icon = $pluginManagerIconPack->getIcon($icon_full_id))) {
      return $element;
    }
    // Build context minimal values as icon_id, optional source and attributes.
    $context = [
      'icon_id' => $icon->getIconId(),
    ];
    // Better to not have source value if not set for the template.
    if ($source = $icon->getSource()) {
      $context['source'] = $source;
    }
    // Silently ensure settings is an array.
    if (!is_array($element['#settings'])) {
      $element['#settings'] = [];
    }
    $extractor_data = $icon->getAllData();
    // Inject attributes variable if not created by the extractor.
    if (!isset($extractor_data['attributes'])) {
      $extractor_data['attributes'] = new Attribute();
    }
    $element['inline-template'] = [
      '#type' => 'inline_template',
      '#template' => $icon->getTemplate(),
      // Context include data from extractor and settings, priority on settings
      // from this element. Context as last value to be sure nothing override
      // icon_id or source if set.
'#context' => array_merge($extractor_data, $element['#settings'], $context),
    ];
    if ($library = $icon->getLibrary()) {
      $element['inline-template']['#attached'] = [
        'library' => [
          $library,
        ],
      ];
    }
    return $element;
  }

}