function getFile()
{
    $promo = params("promo");
    $id = params("id");
    if ($id == null) {
        if ($promo == "-1") {
            $promo = "";
        }
        set("files", File::getAllDocumentByPromo($promo));
    } else {
        set("files", File::getDocumentById($id));
    }
    header('Content-Type: application/json');
    return render("files/getFile.json.php");
}
 public function delete()
 {
     global $bdd;
     $bdd->beginTransaction();
     //deleting promo
     $sql = "DELETE FROM promo_label\n\t\t\t\tWHERE promo = ?";
     $rq = $bdd->prepare($sql);
     $ok = $rq->execute(array($this->getPromo()));
     if (!$ok) {
         $bdd->rollBack();
         return false;
     }
     //deleting files related to the deleted promo
     $files = File::getAllDocumentByPromo($this->getPromo());
     foreach ($files as $file) {
         $ok = $file->delete();
         if (!$ok) {
             $bdd->rollBack();
             return false;
         }
     }
     $bdd->commit();
     return true;
 }