class Aktualnosc extends DataObject {

   static $db = array(
      'Date' => 'Date',
   'Tresc' => 'Text',
   );

static $belongs_many_many = array(
'HomePage' => 'HomePage'
);

public static $has_one = array(
      'Photo' => 'Image'
   );
   
   public static $summary_fields = array(
      'Tresc' => 'Treść',
      'Date' => 'Date',
   );

function getCMSFields() {
$fields = new FieldSet();
    $fields->push( $dateField = new DateField('Date', 'Data aktualności'), 'Content' );
    $fields->push( new TextField('Tresc', 'Krótka treść' ));
    $fields->push( new UploadField( 'Photo', 'Zdjęcie' ) );
    $dateField->setConfig('showcalendar', true);
$dateField->setConfig('dateformat', 'dd-MM-YYYY');
return $fields;
}

}

class HomePage extends Page {
...

static $many_many = array(
'Aktualnosci' => 'Aktualnosc',
);

public function getCMSFields() {
   $fields = parent::getCMSFields();
      
      $gridFieldConfigNews = GridFieldConfig::create()->addComponents(
         new GridFieldToolbarHeader(''),
new GridFieldAddNewButton('toolbar-header-right'),
         new GridFieldSortableHeader(''),
         new GridFieldDataColumns(),
         new GridFieldPaginator(50),
         new GridFieldEditButton(),
         new GridFieldDeleteAction(),
         new GridFieldFilterHeader(''),
         new GridFieldDetailForm()
      );
      $gridfieldNews = new GridField('Aktualnosci', 'Aktualności', $this->Aktualnosci(), $gridFieldConfigNews);
      $fields->addFieldToTab('Root.Aktualnosci', $gridfieldNews);
      

      
return $fields;
      
}

class HomePage_Controller extends Page_Controller {

....
   
}