在PHP从AJAX的来的数据进行转化函数

function utf8RawUrlDecode ($source) {
    $decodedStr = "";
    $pos = 0;
    $len = strlen ($source);
     while ($pos < $len) {
        $charAt = substr ($source, $pos, 1);
         if ($charAt == '%') {
            $pos++;
            $charAt = substr ($source, $pos, 1);
             if ($charAt == 'u') {
                // we got a unicode character
                $pos++;
                $unicodeHexVal = substr ($source, $pos, 4);
                $unicode = hexdec ($unicodeHexVal);
                $entity = "&#". $unicode . ';';