Delete message GridField

GridFieldDetailForm_ItemRequest.php

<?php
class GridFieldDetailForm_ItemRequest extends RequestHandler {

  //...

  public function doDelete($data, $form) {

    try {

      $toDelete = $this->record;
      if (!$toDelete->canDelete()) {
        throw new ValidationException(
          _t('GridFieldDetailForm.DeletePermissionsFailure',"No delete permissions"),0);
      }
      $toDelete->delete();

    } catch(ValidationException $e) {
      $form->sessionMessage($e->getResult()->message(), 'bad');
      return Controller::curr()->redirectBack();
    }

    $toplevelController = $this->getToplevelController();
    if($toplevelController && $toplevelController instanceof LeftAndMain) {
      $backForm = $toplevelController->getEditForm();

      $message = sprintf(
        _t('GridFieldDetailForm.Deleted', 'Deleted %s %s'),
        $this->record->singular_name(),
        ''
      );

      $backForm->sessionMessage($message, 'good');
    }

    //when an item is deleted, redirect to the revelant admin section without the action parameter
    $controller = Controller::curr();
    $controller->getRequest()->addHeader('X-Pjax', 'Content'); // Force a content refresh
    return $controller->redirect($this->getBacklink(), 302); //redirect back to admin section
  }
}