[fw-general] Filter Digits on Zend_Form

[Bagus Nugroho]

Hi All,
I'm trying using 'Digits' filter on Zend_Form like this :
======
class My_Form_Project_Test extends Zend_Form{
 public function __construct($options = null){
  parent::__construct($options);
  
  $update = new Zend_Form_Element_Text('test');
  $update->setLabel('Test')
      ->addFilter('Digits');
      
      
  $submit = new Zend_Form_Element_Submit('submit');
  $submit->setLabel('Submit');
      
      
  $this->addElements(array($update, $submit));
 }
}
 
then, when input '1000asdf', I'm expecting get '1000' but the code above give 
me '1000asdf' instead of '1000' as expected.
Is any wrong with my code above.
..
 
thanks in advance, bn