/**
* Constructor
* @param string $model model name
* @param int $id Primary key of the model. Ignored unless $this->model is set.
* @param string $parent_container The parent container for the form elements
*/
public function __construct($model, $id = null, $parent_container = null)
{
$this->model = $model;
$element = ORM::factory($this->model, $id);
$this->exclude_fields = $element->exclude_fields();
parent::__construct($element, $parent_container);
}