Удаление невалидных символов XML (чаще всего для парсеров API)

                        
<?php 

function stripInvalidXml($value) 

{ 

    $ret = ""; 

    $current; 

    if (empty($value))  

    { 

        return $ret; 

    } 

  

    $length = strlen($value); 

    for ($i=0; $i < $length; $i++) 

    { 

        $current = ord($value{$i}); 

        if (($current == 0x9) || 

            ($current == 0xA) || 

            ($current == 0xD) || 

            (($current >= 0x20) && ($current <= 0xD7FF)) || 

            (($current >= 0xE000) && ($current <= 0xFFFD)) || 

            (($current >= 0x10000) && ($current <= 0x10FFFF))) 

        { 

            $ret .= chr($current); 

        } 

        else 

        { 

            $ret .= " "; 

        } 

    } 

    return $ret; 

}