protected function checkValue($input)
    {
        if ('' === $input || !is_array($this->rootNodes)) {
            return;
        }

        if (false === strpos($input, ',')) {
            $ids = [(int) $input];
        } else {
            $ids = array_map('intval', array_filter(explode(',', $input)));
        }

        if (count(array_diff($ids, array_merge($this->rootNodes, Database::getInstance()->getChildRecords($this->rootNodes, 'tl_news_category')))) > 0) {
            $this->addError($GLOBALS['TL_LANG']['ERR']['invalidPages']);
        }
    }
protected function checkValue($input)
    {
        if ('' === $input || !is_array($this->rootNodes)) {
            return;
        }

        if (false === strpos($input, ',')) {
            $ids = [(int) $input];
        } else {
            $ids = array_map('intval', array_filter(explode(',', $input)));
        }

        if (count(array_diff($ids, array_merge($this->rootNodes, Database::getInstance()->getChildRecords($this->rootNodes, 'tl_news_category')))) > 0) {
            $this->addError($GLOBALS['TL_LANG']['ERR']['invalidPages']);
        }
    }
protected function checkValue ( $ input ) { if ( '' === $ input || ! is_array ( $ this -> rootNodes ) ) { return ; } if ( false === strpos ( $ input , ',' ) ) { $ ids = [ ( int ) $ input ] ; } else { $ ids = array_map ( 'intval' , array_filter ( explode ( ',' , $ input ) ) ) ; } if ( count ( array_diff ( $ ids , array_merge ( $ this -> rootNodes , Database :: getInstance ( ) -> getChildRecords ( $ this -> rootNodes , 'tl_news_category' ) ) ) ) > 0 ) { $ this -> addError ( $ GLOBALS [ 'TL_LANG' ] [ 'ERR' ] [ 'invalidPages' ] ) ; } }
Check the selected value.

@param string $input
Check the selected value .