lib/id/model/has_one.rb in id-0.0.6 vs lib/id/model/has_one.rb in id-0.0.7

@@ -1,13 +1,28 @@
 module Id
   module Model
     class HasOne < Association
 
-      def define
+      def define_getter
         field = self
         model.send :define_method, name do
           memoize field.name do
-            field.type.new(data.fetch(field.key) { raise MissingAttributeError })
+            child = data.fetch(field.key) { raise MissingAttributeError, field.key }
+            field.type.new(child) unless child.nil?
+          end
+        end
+      end
+
+    end
+
+    class HasOneOption < Association
+
+      def define_getter
+        field = self
+        model.send :define_method, name do
+          memoize field.name do
+            child = data.fetch(field.key, nil)
+            child.nil? ? None : Some[field.type.new(child)]
           end
         end
       end
 
     end