fix learning object initialize

app/models/learning_object.rb

@@ -21,7 +21,7 @@ class LearningObject
   validates_presence_of :name, :created_at, :type
 
   def initialize(params={})
-    super(params.merge(defaults))
+    super(params.merge(defaults) { |key, oldval, newval| oldval.blank? ? newval : oldval })
   end
 
   def retrievelink