foreign_key.rb in mongoid-3.0.0

- old
+ new

@@ -60,13 +60,15 @@
       #
       # @return [ Object ] The evolved object.
       #
       # @since 3.0.0
       def evolve(object)
-        return object.id if object.is_a?(Document)
-        evolved = mongoize(object)
-        type.resizable? ? evolved.first : evolved
+        if object_id_field? || object.is_a?(Document)
+          object.__evolve_object_id__
+        else
+          related_id_field.evolve(object)
+        end
       end
 
       # Mongoize the object into the Mongo friendly value.
       #
       # @example Mongoize the object.
@@ -79,20 +81,20 @@
       # @since 3.0.0
       def mongoize(object)
         if type.resizable? || object_id_field?
           type.__mongoize_fk__(constraint, object)
         else
-          metadata.klass.fields["_id"].mongoize(object)
+          related_id_field.mongoize(object)
         end
       end
 
-      # Is the field a BSON::ObjectId?
+      # Is the field a Moped::BSON::ObjectId?
       #
-      # @example Is the field a BSON::ObjectId?
+      # @example Is the field a Moped::BSON::ObjectId?
       #   field.object_id_field?
       #
-      # @return [ true, false ] If the field is a BSON::ObjectId.
+      # @return [ true, false ] If the field is a Moped::BSON::ObjectId.
       #
       # @since 2.2.0
       def object_id_field?
         @object_id_field ||=
           metadata.polymorphic? ? true : metadata.klass.using_object_ids?
@@ -111,9 +113,23 @@
       # @return [ Object ] The called proc.
       #
       # @since 3.0.0
       def evaluate_default_proc(doc)
         serialize_default(default_val[])
+      end
+
+      # Get the id field of the relation.
+      #
+      # @api private
+      #
+      # @example Get the related id field.
+      #   field.related_id_field
+      #
+      # @return [ Fields::Standard ] The field.
+      #
+      # @since 3.0.0
+      def related_id_field
+        @related_id_field ||= metadata.klass.fields["_id"]
       end
 
       # This is used when default values need to be serialized. Most of the
       # time just return the object.
       #