verify if coupon code is existing

core/lib/Thelia/Form/CouponCode.php

@@ -23,6 +23,9 @@
 namespace Thelia\Form;
 
 use Symfony\Component\Validator\Constraints;
+use Symfony\Component\Validator\ExecutionContextInterface;
+use Thelia\Core\Translation\Translator;
+use Thelia\Model\CouponQuery;
 
 /**
  * Class CouponCode
@@ -44,11 +47,25 @@ class CouponCode extends BaseForm
                 "required" => true,
                 "constraints" => array(
                     new Constraints\NotBlank(),
+                    new Constraints\Callback(array(
+                        "methods" => array(
+                            array($this,
+                                "verifyExistingCode")
+                        )
+                    ))
                 )
             )
         );
     }
 
+    public function verifyExistingCode($value, ExecutionContextInterface $context)
+    {
+        $coupon = CouponQuery::create()->findOneByCode($value);
+        if (null === $coupon) {
+            $context->addViolation(Translator::getInstance()->trans("This coupon does not exists"));
+        }
+    }
+
     /**
      * Form name
      *