FormTestEmailForm.php in Drupal 9        
                          
                  
                        
  
  
  
  
File
  core/modules/system/tests/modules/form_test/src/Form/FormTestEmailForm.php
  
    View source  
  <?php
namespace Drupal\form_test\Form;
use Drupal\Core\Form\FormBase;
use Drupal\Core\Form\FormStateInterface;
use Symfony\Component\HttpFoundation\JsonResponse;
class FormTestEmailForm extends FormBase {
  
  public function getFormId() {
    return 'form_test_email';
  }
  
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['email'] = [
      '#type' => 'email',
      '#title' => 'Email address',
      '#description' => 'An email address.',
    ];
    $form['email_required'] = [
      '#type' => 'email',
      '#title' => 'Address',
      '#required' => TRUE,
      '#description' => 'A required email address field.',
    ];
    $form['submit'] = [
      '#type' => 'submit',
      '#value' => 'Submit',
    ];
    return $form;
  }
  
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $form_state
      ->setResponse(new JsonResponse($form_state
      ->getValues()));
  }
}