ViewUI::getStandardButtons

public ViewUI::getStandardButtons(&$form, FormStateInterface $form_state, $form_id, $name = NULL)

public function getStandardButtons(&$form, FormStateInterface $form_state, $form_id, $name = NULL) {
  $form['actions'] = array(
    '#type' => 'actions',
  );

  if (empty($name)) {
    $name = t('Apply');
    if (!empty($this->stack) && count($this->stack) > 1) {
      $name = t('Apply and continue');
    }
    $names = array(t('Apply'), t('Apply and continue'));
  }

  // Forms that are purely informational set an ok_button flag, so we know not
  // to create an "Apply" button for them.
  if (!$form_state->get('ok_button')) {
    $form['actions']['submit'] = array(
      '#type' => 'submit',
      '#value' => $name,
      '#id' => 'edit-submit-' . Html::getUniqueId($form_id),
      // The regular submit handler ($form_id . '_submit') does not apply if
      // we're updating the default display. It does apply if we're updating
      // the current display. Since we have no way of knowing at this point
      // which display the user wants to update, views_ui_standard_submit will
      // take care of running the regular submit handler as appropriate.
      '#submit' => array(array($this, 'standardSubmit')),
      '#button_type' => 'primary',
    );
    // Form API button click detection requires the button's #value to be the
    // same between the form build of the initial page request, and the
    // initial form build of the request processing the form submission.
    // Ideally, the button's #value shouldn't change until the form rebuild
    // step. However, \Drupal\views_ui\Form\Ajax\ViewsFormBase::getForm()
    // implements a different multistep form workflow than the Form API does,
    // and adjusts $view->stack prior to form processing, so we compensate by
    // extending button click detection code to support any of the possible
    // button labels.
    if (isset($names)) {
      $form['actions']['submit']['#values'] = $names;
      $form['actions']['submit']['#process'] = array_merge(array('views_ui_form_button_was_clicked'), \Drupal::service('element_info')->getInfoProperty($form['actions']['submit']['#type'], '#process', array()));
    }
    // If a validation handler exists for the form, assign it to this button.
    $form['actions']['submit']['#validate'][] = [$form_state->getFormObject(), 'validateForm'];
  }

  // Create a "Cancel" button. For purely informational forms, label it "OK".
  $cancel_submit = function_exists($form_id . '_cancel') ? $form_id . '_cancel' : array($this, 'standardCancel');
  $form['actions']['cancel'] = array(
    '#type' => 'submit',
    '#value' => !$form_state->get('ok_button') ? t('Cancel') : t('Ok'),
    '#submit' => array($cancel_submit),
    '#validate' => array(),
    '#limit_validation_errors' => array(),
  );

  // Compatibility, to be removed later: // TODO: When is "later"?
  // We used to set these items on the form, but now we want them on the $form_state:
  if (isset($form['#title'])) {
    $form_state->set('title', $form['#title']);
  }
  if (isset($form['#section'])) {
    $form_state->set('#section', $form['#section']);
  }
  // Finally, we never want these cached -- our object cache does that for us.
  $form['#no_cache'] = TRUE;
}