lib/enju_nii.rb in enju_nii-0.2.1 vs lib/enju_nii.rb in enju_nii-0.3.0.beta.1

@@ -1,6 +1,5 @@
-# -*- encoding: utf-8 -*-
 require "enju_nii/engine"
 require 'open-uri'
 require 'enju_nii/cinii_book'
 
 module EnjuNii
@@ -10,10 +9,10 @@
     end
 
     module ClassMethods
       def enju_nii_cinii_books
         include EnjuNii::CiNiiBook
-        belongs_to :nii_type
+        belongs_to :nii_type, optional: true
       end
 
       def import_isbn(isbn)
         manifestation = Manifestation.import_from_cinii_books(isbn: isbn)
         manifestation