class Url

class Url extends FormElementBase {
  
  /**
   * {@inheritdoc}
   */
  public function getInfo() {
    $class = static::class;
    return [
      '#input' => TRUE,
      '#size' => 60,
      '#maxlength' => 255,
      '#autocomplete_route_name' => FALSE,
      '#process' => [
        [
          $class,
          'processAutocomplete',
        ],
        [
          $class,
          'processAjaxForm',
        ],
        [
          $class,
          'processPattern',
        ],
      ],
      '#element_validate' => [
        [
          $class,
          'validateUrl',
        ],
      ],
      '#pre_render' => [
        [
          $class,
          'preRenderUrl',
        ],
      ],
      '#theme' => 'input__url',
      '#theme_wrappers' => [
        'form_element',
      ],
    ];
  }
  
  /**
   * Form element validation handler for #type 'url'.
   *
   * Note that #maxlength and #required is validated by _form_validate() already.
   */
  public static function validateUrl(&$element, FormStateInterface $form_state, &$complete_form) {
    $value = trim($element['#value']);
    $form_state->setValueForElement($element, $value);
    if ($value !== '' && !UrlHelper::isValid($value, TRUE)) {
      $form_state->setError($element, t('The URL %url is not valid.', [
        '%url' => $value,
      ]));
    }
  }
  
  /**
   * Prepares a #type 'url' render element for input.html.twig.
   *
   * @param array $element
   *   An associative array containing the properties of the element.
   *   Properties used: #title, #value, #description, #size, #maxlength,
   *   #placeholder, #required, #attributes.
   *
   * @return array
   *   The $element with prepared variables ready for input.html.twig.
   */
  public static function preRenderUrl($element) {
    $element['#attributes']['type'] = 'url';
    Element::setAttributes($element, [
      'id',
      'name',
      'value',
      'size',
      'maxlength',
      'placeholder',
    ]);
    static::setAttributes($element, [
      'form-url',
    ]);
    return $element;
  }

}