total in serch model

backend/modules/card/models/UserCardSearch.php

@@ -14,6 +14,7 @@ use backend\modules\card\models\UserCard;
 class UserCardSearch extends UserCard
 {
     public $skills;
+    public $total;
     /**
      * {@inheritdoc}
      */
@@ -86,6 +87,10 @@ class UserCardSearch extends UserCard
 
         $query->orderBy('user_card.created_at DESC');
 
+        $sumQuery = clone $query;
+
+        $this->total = $sumQuery->sum('salary');
+
         return $dataProvider;
     }
 }