1 - unicode2entity - convertir les caracteres unicode (même multiples) en leut codepoint
function unicode2entity($car){
$code='';
$l=mb_strlen($car);
for ($i=0;$i<$l;$i++){
$current_car=mb_substr($car, $i,1);
$code.=sprintf("&#x%04X;", mb_ord($current_car,'UTF-8'));
}
return $code;
}