Re: Sorting one Model only in ModelAdmin

class VAdmin extends ModelAdmin {

   public static $managed_models = array(
      'PCategory',
      'AItem'
   );

   static $url_segment = 'd-admin';
   static $menu_title = 'dAdmin';

   public function getEditForm($id = null, $fields = null) {
      $form = parent::getEditForm($id, $fields);

      if ($this->modelClass == 'AItem') { // add GridFieldSortableRows for AItem GridField only
         $gridField = $form->Fields()->fieldByName($this->sanitiseClassName($this->modelClass));
         $gridField->getConfig()->addComponent(new GridFieldSortableRows('SortOrder'));
      }
      return $form;
   }
}