Implement rename api

@@ -187,12 +187,27 @@ class ItemViewSet(viewsets.ViewSet):
         if request.method == 'POST':
             parent_id = request.POST.get('parent', '')
             name = request.POST.get('name','')
-            parent = get_object_or_None(Item, item_id=parent_id)
-            if parent != None and parent.is_folder == True:
             child = get_object_or_None(Item, item_id=pk)
+
             if child == None:
                 return Response({'message': 'item is not existed.'}, status=status.HTTP_204_NO_CONTENT)
+
+            if parent_id != '':
+                parent = get_object_or_None(Item, item_id=parent_id)
+
+                if parent == None:
+                    return Response({'message': 'parent is not existed.'}, status=status.HTTP_200_OK)
+                if parent.is_folder == False:
+                    return Response({'message': 'parent is not folder.'}, status=status.HTTP_200_OK)
+
+                if parent != None and parent.is_folder == True:
                     child.parent = parent_id
+            else:
+                parent_id = child.parent
+
+            if name != '':
+                child.name = name;
+
             child.save()
             child = Item.objects.filter(item_id = pk)
             child_data = serializers.serialize("json", child)
@@ -203,12 +218,8 @@ class ItemViewSet(viewsets.ViewSet):
             parent_data = serializers.serialize("json", parent)
             json_parent = json.loads(parent_data)[0]['fields']
             res['parentInfo'] = json_parent
+
             return Response({'data': res}, status=status.HTTP_200_OK)
-            if parent == None:
-                return Response({'message': 'parent is not existed.'}, status=status.HTTP_200_OK)
-            if parent.is_folder == False:
-                return Response({'message': 'parent is not folder.'}, status=status.HTTP_200_OK)
-            return Response({'message': 'item is not existed.'}, status=status.HTTP_204_NO_CONTENT)
 
     @action(methods=['POST'], detail=True, permission_classes=[AllowAny], url_path='copy', url_name='copy')
     def copy(self, request, pk):