/** * Normalize tag * * Ensures tag is alphanumeric characters only, and all lowercase. * * @param string $tag * @return string */ public function normalizeTag($tag) { if (!isset($this->_tagFilter)) { require_once IFW_PSN_LIB_ROOT . 'IfwPsn/Vendor/Zend/Filter.php'; require_once IFW_PSN_LIB_ROOT . 'IfwPsn/Vendor/Zend/Filter/Alnum.php'; require_once IFW_PSN_LIB_ROOT . 'IfwPsn/Vendor/Zend/Filter/StringToLower.php'; $this->_tagFilter = new IfwPsn_Vendor_Zend_Filter(); $this->_tagFilter->addFilter(new IfwPsn_Vendor_Zend_Filter_Alnum())->addFilter(new IfwPsn_Vendor_Zend_Filter_StringToLower()); } return $this->_tagFilter->filter($tag); }