♻️ Extract direct ActiveFedora calls to adapter

With Valkyrie looming large, this change refactors the code towards an
adapter pattern; one that will allow for creating a Valkyrie adapter and
then configuring IIIFPrint accordingly.

We'll also need to consider how we duplicate the actor work within a
transaction and/or publisher/listener setup.

There are likely other places where we're making assumptions about
presenters and/or the data models we're processing.

README.md

@@ -115,6 +115,10 @@ uv = createUV('#uv', {
 ## Configuration to enable IiifPrint features
 **NOTE: WorkTypes and models are used synonymously here.**
 
+### Persistence Layer Adapter
+
+We created IiifPrint with an assumption of ActiveFedora.  However, as Hyrax now supports Valkyrie, we need an alternate approach.  We introduced `IiifPrint::Configuration#persistence_layer` as a configuration option.  By default it will use `ActiveFedora` methods; but you can switch adapters to use Valkyrie instead.  (See `IiifPrint::PersistentLayer` for more details).
+
 ### IIIF URL configuration
 
 If you set EXTERNAL_IIIF_URL in your environment, then IiifPrint will use that URL as the root for your IIIF URLs. It will also switch from using the file set ID to using the SHA1 of the file as the identifier. This enables using serverless_iiif or Cantaloupe (refered to as the service) by pointing the service to the same S3 bucket that FCREPO writes the uploaded files to. By setting it up that way you do not need the service to connect to FCREPO or Hyrax at all, both natively support connecting to an S3 bucket to get their data.

app/models/concerns/iiif_print/solr/document.rb

@@ -39,7 +39,7 @@ def digest_sha1
 
   def method_missing(method_name, *args, &block)
     super unless iiif_print_solr_field_names.include? method_name.to_s
-    self[::ActiveFedora.index_field_mapper.solr_name(method_name.to_s)]
+    self[IiifPrint.solr_name(method_name.to_s)]
   end
 
   def respond_to_missing?(method_name, include_private = false)

app/services/iiif_print/manifest_builder_service_behavior.rb

@@ -142,7 +142,7 @@ def get_solr_hits(ids)
       results = []
       ids.each_slice(SOLR_QUERY_PAGE_SIZE) do |paged_ids|
         query = "id:(#{paged_ids.join(' OR ')})"
-        results += ActiveFedora::SolrService.query(
+        results += IiifPrint.solr_query(
           query,
           { fq: "-has_model_ssim:FileSet", rows: paged_ids.size, method: :post }
         )

lib/iiif_print.rb

@@ -44,37 +44,8 @@ def self.config(&block)
   end
 
   class << self
-    delegate :skip_splitting_pdf_files_that_end_with_these_texts, to: :config
-  end
-
-  ##
-  # Return the immediate parent of the given :file_set.
-  #
-  # @param file_set [FileSet]
-  # @return [#work?, Hydra::PCDM::Work]
-  # @return [NilClass] when no parent is found.
-  def self.parent_for(file_set)
-    # fallback to Fedora-stored relationships if work's aggregation of
-    #   file set is not indexed in Solr
-    file_set.parent || file_set.member_of.find(&:work?)
-  end
-
-  ##
-  # Return the parent's parent of the given :file_set.
-  #
-  # @param file_set [FileSet]
-  # @return [#work?, Hydra::PCDM::Work]
-  # @return [NilClass] when no grand parent is found.
-  def self.grandparent_for(file_set)
-    parent_of_file_set = parent_for(file_set)
-    # HACK: This is an assumption about the file_set structure, namely that an image page split from
-    # a PDF is part of a file set that is a child of a work that is a child of a single work.  That
-    # is, it only has one grand parent.  Which is a reasonable assumption for IIIF Print but is not
-    # valid when extended beyond IIIF Print.  That is GenericWork does not have a parent method but
-    # does have a parents method.
-    parent_of_file_set.try(:parent_works).try(:first) ||
-      parent_of_file_set.try(:parents).try(:first) ||
-      parent_of_file_set&.member_of&.find(&:work?)
+    delegate :skip_splitting_pdf_files_that_end_with_these_texts, :persistence_adapter, to: :config
+    delegate :parent_for, :grandparent_for, :solr_construct_query, :solr_query, :solr_name, :clean_for_tests!, to: :persistence_adapter
   end
 
   DEFAULT_MODEL_CONFIGURATION = {

lib/iiif_print/catalog_search_builder.rb

@@ -25,9 +25,9 @@ class CatalogSearchBuilder < Hyrax::CatalogSearchBuilder
     # rubocop:enable Naming/PredicateName
     def show_parents_only(solr_parameters)
       query = if blacklight_params["include_child_works"] == 'true'
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: 'true')
+                IiifPrint.solr_construct_query(is_child_bsi: 'true')
               else
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: nil)
+                IiifPrint.solr_construct_query(is_child_bsi: nil)
               end
       solr_parameters[:fq] += [query]
     end

lib/iiif_print/configuration.rb

@@ -3,6 +3,22 @@ module IiifPrint
   class Configuration
     attr_writer :after_create_fileset_handler
 
+    attr_writer :persistence_adapter
+    def persistence_adapter
+      @persistent_adapter || default_persistence_adapter
+    end
+
+    def default_persistence_adapter
+      # There's probably some configuration of Hyrax we could use to better refine this; but it's
+      # likely a reasonable guess.  The main goal is to not break existing implementations and
+      # maintain an upgrade path.
+      if Gem::Version.new(Hyrax::VERSION) >= Gem::Version.new('6.0.0')
+        IiifPrint::PersistenceLayer::ValkyrieAdapter
+      else
+        IiifPrint::PersistenceLayer::ActiveFedoraAdapter
+      end
+    end
+
     # @param file_set [FileSet]
     # @param user [User]
     def handle_after_create_fileset(file_set, user)

lib/iiif_print/engine.rb

@@ -11,6 +11,12 @@ module IiifPrint
   class Engine < ::Rails::Engine
     isolate_namespace IiifPrint
 
+    initializer 'requires' do
+      require 'iiif_print/persistence_layer'
+      require 'iiif_print/persistence_layer/active_fedora_adapter' if defined?(ActiveFedora)
+      require 'iiif_print/persistence_layer/valkyrie_adapter' if defined?(Valkyrie)
+    end
+
     # rubocop:disable Metrics/BlockLength
     config.to_prepare do
       require "iiif_print/jobs/create_relationships_job"

lib/iiif_print/homepage_search_builder.rb

@@ -7,9 +7,9 @@ class HomepageSearchBuilder < Hyrax::HomepageSearchBuilder
 
     def show_parents_only(solr_parameters)
       query = if blacklight_params["include_child_works"] == 'true'
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: 'true')
+                IiifPrint.solr_construct_query(is_child_bsi: 'true')
               else
-                ActiveFedora::SolrQueryBuilder.construct_query(is_child_bsi: nil)
+                IiifPrint.solr_construct_query(is_child_bsi: nil)
               end
       solr_parameters[:fq] += [query]
     end

lib/iiif_print/persistence_layer.rb

@@ -0,0 +1,40 @@
+module IiifPrint
+  ##
+  # The PersistenceLayer module provides the namespace for other adapters:
+  #
+  # - {IiifPrint::PersistenceLayer::ActiveFedoraAdapter}
+  # - {IiifPrint::PersistenceLayer::ValkyrieAdapter}
+  #
+  # And the defining interface in the {IiifPrint::PersistenceLayer::AbstractAdapter}
+  module PersistenceLayer
+    # @abstract
+    class AbstractAdapter
+      ##
+      # @abstract
+      def self.parent_for(*); end
+
+      ##
+      # @abstract
+      def self.grandparent_for(*); end
+
+      ##
+      # @abstract
+      def self.solr_field_query(*); end
+
+      ##
+      # @abstract
+      def self.clean_for_tests!
+        return false unless Rails.env.test?
+        yield
+      end
+
+      ##
+      # @abstract
+      def self.solr_query(*args); end
+
+      ##
+      # @abstract
+      def self.solr_name(*args); end
+    end
+  end
+end

lib/iiif_print/persistence_layer/active_fedora_adapter.rb

@@ -0,0 +1,65 @@
+module IiifPrint
+  module PersistenceLayer
+    class ActiveFedoraAdapter < AbstractAdapter
+      ##
+      # Return the immediate parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no parent is found.
+      def self.parent_for(file_set)
+        # fallback to Fedora-stored relationships if work's aggregation of
+        #   file set is not indexed in Solr
+        file_set.parent || file_set.member_of.find(&:work?)
+      end
+
+      ##
+      # Return the parent's parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no grand parent is found.
+      def self.grandparent_for(file_set)
+        parent_of_file_set = parent_for(file_set)
+        # HACK: This is an assumption about the file_set structure, namely that an image page split from
+        # a PDF is part of a file set that is a child of a work that is a child of a single work.  That
+        # is, it only has one grand parent.  Which is a reasonable assumption for IIIF Print but is not
+        # valid when extended beyond IIIF Print.  That is GenericWork does not have a parent method but
+        # does have a parents method.
+        parent_of_file_set.try(:parent_works).try(:first) ||
+          parent_of_file_set.try(:parents).try(:first) ||
+          parent_of_file_set&.member_of&.find(&:work?)
+      end
+
+      def self.solr_construct_query(*args)
+        if defined?(Hyrax::SolrQueryBuilderService)
+          Hyrax::SolrQueryBuilderService.construct_query(*args)
+        else
+          ActiveFedora::SolrQueryBuilderService.construct_query(*args)
+        end
+      end
+
+      def self.clean_for_tests!
+        super do
+          ActiveFedora::Cleaner.clean!
+        end
+      end
+
+      def self.solr_query(*args)
+        if defined?(Hyrax::SolrService)
+          Hyrax::SolrService.query(*args)
+        else
+          ActiveFedora::SolrService.query(*args)
+        end
+      end
+
+      def self.solr_name(field_name)
+        if defined?(Hyrax) && Hyrax.config.respond_to?(:index_field_mapper)
+          Hyrax.config.index_field_mapper.solr_name(field_name.to_s)
+        else
+          ::ActiveFedora.index_field_mapper.solr_name(field_name.to_s)
+        end
+      end
+    end
+  end
+end

lib/iiif_print/persistence_layer/valkyrie_adapter.rb

@@ -0,0 +1,45 @@
+module IiifPrint
+  module PersistenceLayer
+    class ValkyrieAdapter < AbstractAdapter
+      ##
+      # Return the immediate parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no parent is found.
+      def self.parent_for(file_set)
+        Hyrax.index_adapter.find_parents(resource: file_set).first
+      end
+
+      ##
+      # Return the parent's parent of the given :file_set.
+      #
+      # @param file_set [FileSet]
+      # @return [#work?, Hydra::PCDM::Work]
+      # @return [NilClass] when no grand parent is found.
+      def self.grandparent_for(file_set)
+        parent = Hyrax.index_adapter.find_parents(resource: file_set).first
+        return nil unless parent
+        Hyrax.index_adapter.find_parents(resource: parent).first
+      end
+
+      def self.solr_construct_query(*args)
+        Hyrax::SolrQueryBuilderService.construct_query(*args)
+      end
+
+      def self.clean_for_tests!
+        # For Fedora backed repositories, we'll want to consider some cleaning mechanism.  For
+        # database backed repositories, we can rely on the database_cleaner gem.
+        raise NotImplementedError
+      end
+
+      def self.solr_query(*args)
+        Hyrax::SolrService.query(*args)
+      end
+
+      def self.solr_name(field_name)
+        Hyrax.config.index_field_mapper.solr_name(field_name.to_s)
+      end
+    end
+  end
+end

spec/iiif_print/configuration_spec.rb

@@ -3,6 +3,12 @@
 RSpec.describe IiifPrint::Configuration do
   let(:config) { described_class.new }
 
+  describe '#persistence_adapter' do
+    subject { config.persistence_adapter }
+
+    it { is_expected.to eq(IiifPrint::PersistenceLayer::ActiveFedoraAdapter) }
+  end
+
   describe '#ancestory_identifier_function' do
     subject(:function) { config.ancestory_identifier_function }
     it "is expected to be a lambda with an arity of one" do

spec/spec_helper.rb

@@ -50,7 +50,7 @@
     ::Noid::Rails.config.minter_class = minter_class
     Hyrax.config.noid_minter_class = minter_class
 
-    ActiveFedora::Cleaner.clean!
+    IiifPrint.clean_for_tests!
     DatabaseCleaner.clean_with(:truncation)
 
     begin