/** * Return an instance of InputFilter * * @return InputFilter */ public function getInputFilter() { if (!isset($this->inputFilter)) { $inputFilter = parent::getInputFilter(); // count $count = new Input('count'); $count->setAllowEmpty(true); $count->getFilterChain()->attach(new Int()); $count->getValidatorChain()->attach(new Digits()); $inputFilter->add($count); $this->inputFilter = $inputFilter; } return $this->inputFilter; }