Url.php

<?php

namespace Drupal\Core\Render\Element;

use Drupal\Component\Utility\UrlHelper;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\Render\Attribute\FormElement;
use Drupal\Core\Render\Element;

/**
 * Provides a form element for input of a URL.
 *
 * Properties:
 * - #default_value: A valid URL string.
 * - #size: The size of the input element in characters.
 * - #pattern: A string for the native HTML5 pattern attribute.
 *
 * Usage example:
 * @code
 * $form['homepage'] = array(
 *   '#type' => 'url',
 *   '#title' => $this->t('Home Page'),
 *   '#size' => 30,
 *   '#pattern' => '*.example.com',
 *   ...
 * );
 * @endcode
 *
 * @see \Drupal\Core\Render\Element\Textfield
 */

#[FormElement('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;
  }

}