Merge pull request #73 from projecthydra/mixin

Add a module mixin to make integration easier

README.md

@@ -63,26 +63,14 @@ noid_service.valid? 'xyz123foobar'
 
 ## ActiveFedora integration
 
-To get ActiveFedora to automatically call your Noid service whenever a new ActiveFedora object is saved, create a method on your model called `assign_id` and have it talk to your Noid service, e.g.:
+To get ActiveFedora to automatically call your Noid service whenever a new ActiveFedora object is saved, include the `ActiveFedora::Noid::Model`, e.g.:
 
 ```ruby
 # app/models/my_object.rb
 require 'active_fedora/noid'
 
 class MyObject < ActiveFedora::Base
-  # ...
-
-  def assign_id
-    noid_service.mint
-  end
-
-  # ...
-
-  private
-
-    def noid_service
-      @noid_service ||= ActiveFedora::Noid::Service.new
-    end
+  include ActiveFedora::Noid::Model
 end
 ```
 

lib/active_fedora/noid.rb

@@ -4,6 +4,7 @@
 require 'active_fedora/noid/engine'
 require 'active_fedora/noid/service'
 require 'active_fedora/noid/minter'
+require 'active_fedora/noid/model'
 
 module ActiveFedora
   module Noid

lib/active_fedora/noid/model.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module ActiveFedora
+  module Noid
+    # Mix this class into an ActiveFedora:Base model in order to have you new objects
+    # created with a noid id.
+    module Model
+      ## This overrides the default behavior, which is to ask Fedora for an id
+      # @see ActiveFedora::Persistence.assign_id
+      def assign_id
+        service.mint
+      end
+
+      private
+
+      def service
+        @service ||= ActiveFedora::Noid::Service.new
+      end
+    end
+  end
+end

spec/models/active_fedora/noid/model_spec.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+require 'spec_helper'
+
+RSpec.describe ActiveFedora::Noid::Model do
+  let(:sample_class) do
+    Class.new(ActiveFedora::Base) do
+      include ActiveFedora::Noid::Model
+    end
+  end
+  let(:instance) { sample_class.new }
+  let(:service) { instance_double(ActiveFedora::Noid::Service, mint: '1234') }
+
+  before do
+    allow(ActiveFedora::Noid::Service).to receive(:new).and_return(service)
+  end
+
+  describe '#assign_id' do
+    it 'returns the id from the noid service' do
+      expect(instance.assign_id).to eq '1234'
+    end
+  end
+end