SingleDateTimeWidget.php in Single DateTimePicker 8        
                          
                  
                        
  
  
  
  
  
File
  src/Plugin/Field/FieldWidget/SingleDateTimeWidget.php
  
    View source  
  <?php
namespace Drupal\single_datetime\Plugin\Field\FieldWidget;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\datetime\Plugin\Field\FieldType\DateTimeItem;
use Drupal\datetime\Plugin\Field\FieldType\DateTimeItemInterface;
class SingleDateTimeWidget extends SingleDateTimeBase {
  
  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, FormStateInterface $form_state) {
    $element = parent::formElement($items, $delta, $element, $form, $form_state);
    $date_type = $this
      ->getFieldSetting('datetime_type');
    
    $element['value'] = [
      '#title' => $element['#title'],
      '#type' => 'single_date_time',
      '#date_timezone' => date_default_timezone_get(),
      '#default_value' => NULL,
      '#date_type' => $date_type,
      '#required' => $element['#required'],
      '#description' => $element['#description'],
    ];
    if ($date_type === DateTimeItem::DATETIME_TYPE_DATE) {
      
      $element['value']['#date_timezone'] = DateTimeItemInterface::STORAGE_TIMEZONE;
      
      $format = DateTimeItemInterface::DATE_STORAGE_FORMAT;
    }
    else {
      
      $format = $this
        ->getSetting('hour_format') === '12h' ? 'Y-m-d h:i:s A' : 'Y-m-d H:i:s';
    }
    
    $element['value'] = array_merge($element['value'], $this
      ->getCommonElementSettings());
    if ($items[$delta]->date) {
      $date = $items[$delta]->date;
      
      $element['value']['#default_value'] = $this
        ->formatDefaultValue($date, $element['value']['#date_timezone'], $format);
    }
    return $element;
  }
}