class DatetimeElementFormTest

class DatetimeElementFormTest extends KernelTestBase implements FormInterface {
  
  /**
   * The variable under test.
   *
   * @var string
   */
  protected $flag;
  
  /**
   * Modules to enable.
   *
   * @var array
   */
  public static $modules = [
    'datetime',
    'system',
  ];
  
  /**
   * Sets up the test.
   */
  protected function setUp() {
    parent::setUp();
  }
  
  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'test_datetime_element';
  }
  
  /**
   * {@inheritdoc}
   */
  public function datetimecallback($date) {
    $this->flag = 'Date time callback called.';
  }
  
  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $form['datetime_element'] = [
      '#title' => 'datelist test',
      '#type' => 'datetime',
      '#default_value' => new DrupalDateTime('2000-01-01 00:00:00'),
      '#date_date_format' => 'Y-m-d',
      '#date_time_format' => 'H:i:s',
      '#date_date_element' => 'HTML Date',
      '#date_time_element' => 'HTML Time',
      '#date_increment' => 1,
      '#date_date_callbacks' => [
        [
          $this,
          'datetimecallback',
        ],
      ],
    ];
    // Element without specifying the default value.
    $form['simple_datetime_element'] = [
      '#type' => 'datetime',
      '#date_date_format' => 'Y-m-d',
      '#date_time_format' => 'H:i:s',
      '#date_date_element' => 'HTML Date',
      '#date_time_element' => 'HTML Time',
    ];
    $form['submit'] = [
      '#type' => 'submit',
      '#value' => t('Submit'),
    ];
    return $form;
  }
  
  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
  }
  
  /**
   * Form validation handler.
   *
   * @param array $form
   *   An associative array containing the structure of the form.
   * @param \Drupal\Core\Form\FormStateInterface $form_state
   *   The current state of the form.
   */
  public function validateForm(array &$form, FormStateInterface $form_state) {
  }
  
  /**
   * Tests that default handlers are added even if custom are specified.
   */
  public function testDatetimeElement() {
    $form = \Drupal::formBuilder()->getForm($this);
    $this->render($form);
    $this->assertEqual(t('Date time callback called.'), $this->flag);
  }
  
  /**
   * Tests proper timezone handling of the Datetime element.
   */
  public function testTimezoneHandling() {
    // Render the form once with the site's timezone.
    $form = \Drupal::formBuilder()->getForm($this);
    $this->render($form);
    $this->assertEquals('Australia/Sydney', $form['datetime_element']['#date_timezone']);
    // Mimic a user with a different timezone than Australia/Sydney.
    date_default_timezone_set('UTC');
    $form = \Drupal::formBuilder()->getForm($this);
    $this->render($form);
    $this->assertEquals('UTC', $form['datetime_element']['#date_timezone']);
  }

}