add validation of existing file

Entity/StoredObject.php

@@ -6,6 +6,7 @@ namespace Chill\DocStoreBundle\Entity;
 
 use Doctrine\ORM\Mapping as ORM;
 use ChampsLibres\AsyncUploaderBundle\Model\AsyncFileInterface;
+use ChampsLibres\AsyncUploaderBundle\Validator\Constraints\AsyncFileExists;
 
 /**
  * Represent a document stored in an object store 
@@ -14,6 +15,9 @@ use ChampsLibres\AsyncUploaderBundle\Model\AsyncFileInterface;
  * 
  * @ORM\Entity()
  * @ORM\Table("chill_doc.stored_object")
+ * @AsyncFileExists(
+ *  message="The file is not stored properly"
+ * )
  */
 class StoredObject implements AsyncFileInterface
 {