[wings] Round trip registered valkyrie native classes

lib/wings.rb

@@ -15,11 +15,50 @@
 # However, these dependencies should be considered temprorary: this code will
 # be deprecated for removal in a future release.
 #
+# @example casting an ActiveFedora model to Valkyrie
+#   work     = GenericWork.create(title: ['Comet in Moominland'])
+#   resource = work.valkyrie_resource
+#
+#   resource.title # => ["Comet in Moominland"]
+#   resource.title = ["Mumintrollet på kometjakt"]
+#
+#   Hyrax.persister.save(resource: resource)
+#
+#   work.reload
+#   work.title # => ["Mumintrollet på kometjakt"]
+#
+# @example defining a native Valkyrie model for use with Wings
+#   # given an `ActiveFodora` model like
+#   class Book < ActiveFedora::Base
+#     property :author, predicate: ::RDF::URI('http://example.com/ns/author')
+#     property :title,  predicate: ::RDF::URI('http://example.com/ns/title')
+#   end
+#
+#   # define a `Valkyrie` model with matching attributes,
+#   class BookResource < Hyrax::Resource
+#     attribute :author, Valkyrie::Types::String
+#     attribute :title,  Valkyrie::Types::String
+#   end
+#
+#   # and register the relationship with `Wings`
+#   Wings::ModelRegistry.register(BookResource, Book)
+#
+#   # `Wings` will cast the `BookResource` to a `Book` to persist via `ActiveFedora`
+#   resource = BookResource.new(author: 'Tove Jansson', title: 'Comet in Moominland')
+#   adapter  = Wings::Valkyrie::MetadataAdapter.new
+#   resource = adapter.persister.save(resource: resource)
+#
+#   resource.title  # => ["Comet in Moominland"]
+#   resource.author # => ["Tove Jansson"]
+#
+#   resource.is_a?(BookResource) # => true
+#
 # @see https://wiki.duraspace.org/display/samvera/Hyrax-Valkyrie+Development+Working+Group
 #      for further context regarding the approach
 module Wings; end
 
 require 'valkyrie'
+require 'wings/model_registry'
 require 'wings/model_transformer'
 require 'wings/orm_converter'
 require 'wings/attribute_transformer'
@@ -52,6 +91,10 @@ module Wings; end
   Valkyrie.config.metadata_adapter.query_service.custom_queries.register_query_handler(query_handler)
 end
 
+Wings::ModelRegistry.register(Hyrax::AccessControl, Hydra::AccessControl)
+Wings::ModelRegistry.register(Hyrax::Embargo,       Hydra::AccessControls::Embargo)
+Wings::ModelRegistry.register(Hyrax::Lease,         Hydra::AccessControls::Lease)
+
 Hydra::AccessControl.send(:define_method, :valkyrie_resource) do
   attrs = attributes.symbolize_keys
   attrs[:new_record]  = new_record?

lib/wings/active_fedora_converter.rb

@@ -65,11 +65,10 @@ def convert
 
     def active_fedora_class
       klass = resource.internal_resource.constantize
+
       return klass if klass <= ActiveFedora::Base
-      return Hydra::AccessControl           if klass <= Hyrax::AccessControl
-      return Hydra::AccessControls::Embargo if klass <= Hyrax::Embargo
-      return Hydra::AccessControls::Lease   if klass <= Hyrax::Lease
-      DefaultWork
+
+      ModelRegistry.lookup(klass) || DefaultWork
     end
 
     ##

lib/wings/model_registry.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+module Wings
+  ##
+  # This registry provides an off-ramp for legacy ActiveFedora models.
+  #
+  # New valkyrie models can be defined manually and registered as an analogue
+  # of an existing `ActiveFedora::Base` implementer. This allows Wings to cast
+  # the new model to the legacy model when saving, ensuring backwards compatible
+  # data on save.
+  #
+  # Several models from Hyrax components have default mappings provided by Wings.
+  #
+  # @example
+  #   Wings::ModelRegistry.register(NewValkyrieModel, OldActiveFedoraModel)
+  #
+  #   Wings::ModelRegistry.lookup(NewValkyrieModel) # => OldActiveFedoraModel
+  #   Wings::ModelRegistry.reverse_lookup(OldActiveFedoraModel) # => NewValkyrieModel
+  #
+  class ModelRegistry
+    include Singleton
+
+    def self.register(*args)
+      instance.register(*args)
+    end
+
+    def self.lookup(*args)
+      instance.lookup(*args)
+    end
+
+    def self.reverse_lookup(*args)
+      instance.reverse_lookup(*args)
+    end
+
+    def initialize
+      @map = {}
+    end
+
+    def register(valkyrie, active_fedora)
+      @map[valkyrie] = active_fedora
+    end
+
+    def lookup(valkyrie)
+      @map[valkyrie]
+    end
+
+    def reverse_lookup(active_fedora)
+      @map.rassoc(active_fedora)&.first
+    end
+  end
+end

lib/wings/orm_converter.rb

@@ -29,13 +29,7 @@ def self.relationship_keys_for(reflections:)
     #
     # @return [Class]
     def self.base_for(klass:)
-      if klass == Hydra::AccessControls::Embargo
-        Hyrax::Embargo
-      elsif klass == Hydra::AccessControls::Lease
-        Hyrax::Lease
-      else
-        Hyrax::Resource
-      end
+      ModelRegistry.reverse_lookup(klass) || Hyrax::Resource
     end
 
     ##

spec/support/book_resource.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+module Hyrax
+  module Test
+    class BookResource < Hyrax::Resource
+      attribute :author,   Valkyrie::Types::String
+      attribute :created,  Valkyrie::Types::Date
+      attribute :isbn,     Valkyrie::Types::String
+      attribute :pubisher, Valkyrie::Types::String
+      attribute :title,    Valkyrie::Types::String
+    end
+
+    class Book < ActiveFedora::Base
+      property :author,    predicate: ::RDF::URI('http://example.com/ns/author')
+      property :created,   predicate: ::RDF::URI('http://example.com/ns/created')
+      property :isbn,      predicate: ::RDF::URI('http://example.com/ns/isbn')
+      property :publisher, predicate: ::RDF::URI('http://example.com/ns/publisher')
+      property :title,     predicate: ::RDF::URI("http://example.com/ns/title")
+    end
+  end
+end
+
+Wings::ModelRegistry.register(Hyrax::Test::BookResource, Hyrax::Test::Book)

spec/wings/active_fedora_converter_spec.rb

@@ -21,6 +21,28 @@
       expect(converter.convert).to eq work
     end
 
+    context 'when given a valkyrie native model' do
+      let(:resource) { klass.new }
+
+      let(:klass) do
+        class ConverterDummyResource < Valkyrie::Resource; end
+        ConverterDummyResource
+      end
+
+      it 'gives a default work' do
+        expect(converter.convert)
+          .to be_a Wings::ActiveFedoraConverter::DefaultWork
+      end
+
+      context 'and it is registered' do
+        let(:resource) { Hyrax::Test::BookResource.new }
+
+        it 'maps to the registered ActiveFedora class' do
+          expect(converter.convert).to be_a Hyrax::Test::Book
+        end
+      end
+    end
+
     context 'with attributes' do
       let(:attributes) do
         FactoryBot.attributes_for(:generic_work)

spec/wings/model_transformer_spec.rb

@@ -257,7 +257,7 @@
     let(:page2)       { page_class.new(id: 'pg2') }
 
     let(:book_class) do
-      Book = Class.new(ActiveFedora::Base) do
+      Monograph = Class.new(ActiveFedora::Base) do
         has_many :pages
         property :title, predicate: ::RDF::Vocab::DC.title
         property :contributor, predicate: ::RDF::Vocab::DC.contributor
@@ -273,7 +273,7 @@
 
     after do
       Object.send(:remove_const, :Page)
-      Object.send(:remove_const, :Book)
+      Object.send(:remove_const, :Monograph)
     end
 
     let(:attributes) do

spec/wings/orm_converter_spec.rb

@@ -24,5 +24,14 @@
         expect { described_class.to_valkyrie_resource_class(klass: String) }.to raise_error
       end
     end
+
+    context 'when given a registered class' do
+      it 'returns a subclass of the corresponding native valkyrie resource' do
+        klass = Wings::ModelRegistry.lookup(Hyrax::Test::BookResource)
+
+        expect(described_class.to_valkyrie_resource_class(klass: klass).ancestors)
+          .to include Hyrax::Test::BookResource
+      end
+    end
   end
 end

spec/wings/valkyrie/persister_spec.rb

@@ -6,22 +6,26 @@
 RSpec.describe Wings::Valkyrie::Persister do
   context "When passing a Valkyrie::Resource converted from an ActiveFedora::Base" do
     before do
-      class Book < ActiveFedora::Base
-        include Hydra::AccessControls::Permissions
-        include Hyrax::CoreMetadata
-        include Hydra::WithDepositor
-        property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
+      module Hyrax::Test
+        module Persister
+          class Book < ActiveFedora::Base
+            include Hydra::AccessControls::Permissions
+            include Hyrax::CoreMetadata
+            include Hydra::WithDepositor
+            property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
+          end
+        end
       end
     end
 
     after do
-      Object.send(:remove_const, :Book)
+      Hyrax::Test.send(:remove_const, :Persister)
     end
 
     subject(:persister) { described_class.new(adapter: adapter) }
     let(:adapter) { Wings::Valkyrie::MetadataAdapter.new }
     let(:query_service) { adapter.query_service }
-    let(:af_resource_class) { Book }
+    let(:af_resource_class) { Hyrax::Test::Persister::Book }
     let(:resource_class) { Wings::OrmConverter.to_valkyrie_resource_class(klass: af_resource_class) }
     let(:resource) { resource_class.new(title: ['Foo']) }
 

spec/wings/valkyrie/query_service_spec.rb

@@ -5,31 +5,35 @@
 
 RSpec.describe Wings::Valkyrie::QueryService do
   before do
-    class Book < ActiveFedora::Base
-      include Hyrax::WorkBehavior
-      include Hydra::AccessControls::Permissions
-      property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
-      property :a_member_of, predicate: ::RDF::URI.new('http://www.example.com/a_member_of'), multiple: true do |index|
-        index.as :symbol
+    module Hyrax::Test
+      module QueryService
+        class Book < ActiveFedora::Base
+          include Hyrax::WorkBehavior
+          include Hydra::AccessControls::Permissions
+          property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
+          property :a_member_of, predicate: ::RDF::URI.new('http://www.example.com/a_member_of'), multiple: true do |index|
+            index.as :symbol
+          end
+          property :an_ordered_member_of, predicate: ::RDF::URI.new('http://www.example.com/an_ordered_member_of'), multiple: true
+        end
+
+        class Image < ActiveFedora::Base
+          include Hydra::AccessControls::Permissions
+          property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
+        end
       end
-      property :an_ordered_member_of, predicate: ::RDF::URI.new('http://www.example.com/an_ordered_member_of'), multiple: true
-    end
-    class Image < ActiveFedora::Base
-      include Hydra::AccessControls::Permissions
-      property :title, predicate: ::RDF::Vocab::DC.title, multiple: true
     end
   end
 
   after do
-    Object.send(:remove_const, :Book)
-    Object.send(:remove_const, :Image)
+    Hyrax::Test.send(:remove_const, :QueryService)
   end
 
   subject(:query_service) { described_class.new(adapter: adapter) }
   let(:adapter) { Wings::Valkyrie::MetadataAdapter.new }
   let(:persister) { Wings::Valkyrie::Persister.new(adapter: adapter) }
-  let(:af_resource_class) { Book }
-  let(:af_image_resource_class) { Image }
+  let(:af_resource_class) { Hyrax::Test::QueryService::Book }
+  let(:af_image_resource_class) { Hyrax::Test::QueryService::Image }
   let(:resource_class) { Wings::OrmConverter.to_valkyrie_resource_class(klass: af_resource_class) }
   let(:image_resource_class) { Wings::OrmConverter.to_valkyrie_resource_class(klass: af_image_resource_class) }
   let(:resource) { resource_class.new(title: ['Foo']) }