themes add and some fix

kernel/RestController.php

@@ -94,7 +94,9 @@ class RestController
         $model = $this->model->where('id', $id)->first();
 
         foreach ($model->getFillable() as $item){
-            $model->{$item} = $data[$item] ?? null;
+            if (!empty($data[$item])){
+                $model->{$item} = $data[$item] ?? null;
+            }
         }
 
         $model->save();