I know there are skip attributes like below. But is there an optionalAttribute() or anything? For example, if a user registers with Google+ instead of the default login form, he won't need his email so it should allow an optional value.
public function initialize()
{
//Skips fields/columns on both INSERT/UPDATE operations
// $this->skipAttributes(array('year', 'price'));
//Skips only when inserting
// $this->skipAttributesOnCreate(array('created_at'));
//Skips only when updating
// $this->skipAttributesOnUpdate(array('modified_in'));
}