3 namespace Drupal\Core\Render\Element;
5 use Drupal\Core\Form\FormStateInterface;
6 use Drupal\Core\Render\Element;
9 * Provides a slider for input of a number within a specific range.
11 * Provides an HTML5 input element with type of "range".
14 * - #min: Minimum value (defaults to 0).
15 * - #max: Maximum value (defaults to 100).
16 * Refer to \Drupal\Core\Render\Element\Number for additional properties.
20 * $form['quantity'] = array(
22 * '#title' => $this->t('Quantity'),
26 * @see \Drupal\Core\Render\Element\Number
28 * @FormElement("range")
30 class Range extends Number {
35 public function getInfo() {
36 $info = parent::getInfo();
37 $class = get_class($this);
42 [$class, 'preRenderRange'],
44 '#theme' => 'input__range',
49 * Prepares a #type 'range' render element for input.html.twig.
51 * @param array $element
52 * An associative array containing the properties of the element.
53 * Properties used: #title, #value, #description, #min, #max, #attributes,
57 * The $element with prepared variables ready for input.html.twig.
59 public static function preRenderRange($element) {
60 $element['#attributes']['type'] = 'range';
61 Element::setAttributes($element, ['id', 'name', 'value', 'step', 'min', 'max']);
62 static::setAttributes($element, ['form-range']);
70 public static function valueCallback(&$element, $input, FormStateInterface $form_state) {
72 $offset = ($element['#max'] - $element['#min']) / 2;
75 if (strtolower($element['#step']) != 'any') {
76 $steps = round($offset / $element['#step']);
77 $offset = $element['#step'] * $steps;
80 return $element['#min'] + $offset;