public function getStorageField($key)
    {
        $pos = strpos($key, $this->keySeparator);

        if ($pos) {
            return substr($key, 0, $pos);
        }

        return null;
    }
public function getStorageField($key)
    {
        $pos = strpos($key, $this->keySeparator);

        if ($pos) {
            return substr($key, 0, $pos);
        }

        return null;
    }
public function getStorageField ( $ key ) { $ pos = strpos ( $ key , $ this -> keySeparator ) ; if ( $ pos ) { return substr ( $ key , 0 , $ pos ) ; } return null ; }
Get the storage field name from a combined field name

@param string $key
@return string The storage name or null when not a key name
Get the storage field name from a combined field name