/**
* Verify course
*
* @param string action (optional)
* @return bool true on sucess
*/
public function verify($action = NULL)
{
// If action is 'add', make sure that course id/alias is unique
if ($action == 'add') {
$warehouse = new Warehouse();
$courseIdExists = $warehouse->getCourseByAlias($this->getCourseId());
if ($courseIdExists) {
throw new \Exception(Lang::txt('Course with this alias already exists.'));
}
}
parent::verify($action);
}