fix tiding

app/models/tiding.rb

@@ -9,16 +9,15 @@ class Tiding < ApplicationRecord
 
   def identifier
     value = nil
-    if Object.const_defined?(container_type)
-      value = container.try(:identifier)
-    end
 
-    if value.blank? && parent_container_type && Object.const_defined?(parent_container_type)
-      value = parent_container_type.try(:identifier)
+    value = container.try(:identifier) rescue nil
+
+    if value.blank? && parent_container_type
+      value = parent_container_type.try(:identifier) rescue nil
     end
 
-    if value.blank? && belong_container_type && Object.const_defined?(belong_container_type)
-      value = belong_container.try(:identifier)
+    if value.blank? && belong_container_type
+      value = belong_container.try(:identifier) rescue nil
     end
 
     value