JavascriptStatesForm.php

<?php

namespace Drupal\form_test\Form;

use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;

/**
 * Builds a simple form to test states.
 *
 * @see \Drupal\FunctionalJavascriptTests\Core\Form\JavascriptStatesTest
 */
class JavascriptStatesForm extends FormBase {
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'javascript_states_form';
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['select'] = [
      '#type' => 'select',
      '#title' => 'select 1',
      '#options' => [
        0 => 0,
        1 => 1,
        2 => 2,
      ],
    ];
    $form['number'] = [
      '#type' => 'number',
      '#title' => 'enter 1',
    ];
    $form['textfield'] = [
      '#type' => 'textfield',
      '#title' => 'textfield',
      '#states' => [
        'visible' => [
          [
            ':input[name="select"]' => [
              'value' => '1',
            ],
          ],
          'or',
          [
            ':input[name="number"]' => [
              'value' => '1',
            ],
          ],
        ],
      ],
    ];
    return $form;
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
  }

}