Output Clean Buffer

ob_start('cleanOutput');
function cleanOutput($buffer) {
    $search = array(
        '/\>[^\S ]+/s', //strip whitespaces after tags, except space
        '/[^\S ]+\</s', //strip whitespaces before tags, except space
        '/(\s)+/s'  // shorten multiple whitespace sequences
    );
    $replace = array(
        '>', '<', '\\1'
    );
    $buffer = preg_replace($search, $replace, $buffer);
    return $buffer;
}