FormTestRangeForm.php

<?php

namespace Drupal\form_test\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Symfony\Component\HttpFoundation\JsonResponse;

/**
 * Form constructor for testing #type 'range' elements.
 *
 * @internal
 */
class FormTestRangeForm extends FormBase {
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'form_test_range';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['with_default_value'] = [
            '#type' => 'range',
            '#title' => 'Range with default value',
            '#min' => 10,
            '#max' => 20,
            '#step' => 2,
            '#default_value' => 18,
            '#description' => 'The default value is 18.',
        ];
        $form['float'] = [
            '#type' => 'range',
            '#title' => 'Float',
            '#min' => 10,
            '#max' => 11,
            '#step' => 'any',
            '#description' => 'Floating point number between 10 and 11.',
        ];
        $form['integer'] = [
            '#type' => 'range',
            '#title' => 'Integer',
            '#min' => 2,
            '#max' => 8,
            '#step' => 2,
            '#description' => 'Even integer between 2 and 8.',
        ];
        $form['offset'] = [
            '#type' => 'range',
            '#title' => 'Offset',
            '#min' => 2.9,
            '#max' => 10.9,
            '#description' => 'Value between 2.9 and 10.9.',
        ];
        $form['submit'] = [
            '#type' => 'submit',
            '#value' => 'Submit',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $form_state->setResponse(new JsonResponse($form_state->getValues()));
    }

}