Refactor DisplayImagePresenterBehavior

This commit will add OVERRIDE comments where useful and add a blurb in
the README for this new feature.  The #display_content method was added
to support presentation 3 manifests.  `SERVERLESS` has been renamed to
`EXTERNAL`.  `DisplayImagePresenterBehavior` has beeen refactored to
incorporate existing code.  Specs have also been refactored.

README.md

@@ -38,6 +38,7 @@ IiifPrint supports:
 * configuring how the manifest canvases are sorted in the viewer
 * adding metadata fields to the manifest with faceted search links and external links
 * excluding specified work types to be found in the catalog search
+* external IIIF image urls that work with services such as AWS
 
 A complete list of features can be found [here](https://github.com/scientist-softserv/iiif_print/wiki/Features-List).
 
@@ -153,7 +154,7 @@ TO ENABLE OCR Search (from the UV and catalog search)
     }
 ```
 
-To remove child works from recent works on homepage 
+To remove child works from recent works on homepage
 ### homepage_controller.rb
 * In the HomepageController, change the search_builder_class to remove works from recent_documents if `is_child_bsi: true`
 ```rb

app/indexers/concerns/iiif_print/file_set_indexer.rb

@@ -27,7 +27,7 @@ def generate_solr_document
       end
     end
 
-        private
+    private
 
     def digest_from_content
       return unless object.original_file

app/presenters/iiif_print/iiif_manifest_presenter_behavior.rb

@@ -3,6 +3,10 @@ module IiifPrint
   module IiifManifestPresenterBehavior
     extend ActiveSupport::Concern
 
+    # Extending the presenter to the base url which includes the protocol.
+    # We need the base url to render the facet links and normalize the interface.
+    attr_accessor :base_url
+
     def manifest_metadata
       @manifest_metadata ||= IiifPrint.manifest_metadata_from(work: model, presenter: self)
     end
@@ -11,7 +15,7 @@ def search_service
       Rails.application.routes.url_helpers.solr_document_iiif_search_url(id, host: hostname)
     end
 
-    # OVERRIDE Hyrax 3x, avoid nil returning to IIIF Manifest gem
+    # OVERRIDE: Hyrax 3x, avoid nil returning to IIIF Manifest gem
     # @see https://github.com/samvera/iiif_manifest/blob/c408f90eba11bef908796c7236ba6bcf8d687acc/lib/iiif_manifest/v3/manifest_builder/record_property_builder.rb#L28
     ##
     # @return [Array<Hash{String => String}>]
@@ -26,20 +30,47 @@ def sequence_rendering
       end.flatten
     end
 
+    # OVERRIDE: Hyrax v3.x
     module DisplayImagePresenterBehavior
+      # Extending the presenter to the base url which includes the protocol.
+      # We need the base url to render the facet links and normalize the interface.
+      attr_accessor :base_url
+
+      # Extending this class because there is an #ability= but not #ability and this definition
+      # mirrors the Hyrax::IiifManifestPresenter#ability.
+      def ability
+        @ability ||= NullAbility.new
+      end
+
       def display_image
         return nil unless latest_file_id
+        return nil unless model.image?
+        return nil unless IiifPrint.config.default_iiif_manifest_version == 2
 
         IIIFManifest::DisplayImage
           .new(display_image_url(hostname),
-              format: image_format(alpha_channels),
-              width: width,
-              height: height,
-              iiif_endpoint: iiif_endpoint(latest_file_id, base_url: hostname))
+            format: image_format(alpha_channels),
+            width: width,
+            height: height,
+            iiif_endpoint: iiif_endpoint(latest_file_id, base_url: hostname))
+      end
+
+      # OVERRIDE: IIIF Hyrax AV v0.2 #display_content for prez 3 manifests
+      def display_content
+        return nil unless latest_file_id
+        return super unless model.image?
+
+        IIIFManifest::V3::DisplayContent
+          .new(display_image_url(hostname),
+            format: image_format(alpha_channels),
+            width: width,
+            height: height,
+            type: 'Image',
+            iiif_endpoint: iiif_endpoint(latest_file_id, base_url: hostname))
       end
 
       def display_image_url(base_url)
-        if ENV['SERVERLESS_IIIF_URL'].present?
+        if ENV['EXTERNAL_IIIF_URL'].present?
           # At the moment we are only concerned about Hyrax's default image url builder
           iiif_image_url_builder(url_builder: Hyrax.config.iiif_image_url_builder)
         else
@@ -48,9 +79,9 @@ def display_image_url(base_url)
       end
 
       def iiif_endpoint(file_id, base_url: request.base_url)
-        if ENV['SERVERLESS_IIIF_URL'].present?
+        if ENV['EXTERNAL_IIIF_URL'].present?
           IIIFManifest::IIIFEndpoint.new(
-            File.join(ENV['SERVERLESS_IIIF_URL'], file_id),
+            File.join(ENV['EXTERNAL_IIIF_URL'], file_id),
             profile: Hyrax.config.iiif_image_compliance_level_uri
           )
         else
@@ -71,21 +102,21 @@ def work?
       private
 
       def latest_file_id
-        if ENV['SERVERLESS_IIIF_URL'].present?
-          serverless_latest_file_id
+        if ENV['EXTERNAL_IIIF_URL'].present?
+          external_latest_file_id
         else
           super
         end
       end
 
-      def serverless_latest_file_id
+      def external_latest_file_id
         @latest_file_id ||= digest_sha1
       end
 
       def iiif_image_url_builder(url_builder:)
         args = [
           latest_file_id,
-          ENV['SERVERLESS_IIIF_URL'],
+          ENV['EXTERNAL_IIIF_URL'],
           Hyrax.config.iiif_image_size_default
         ]
         # In Hyrax 3, Hyrax.config.iiif_image_url_builder takes an additional argument

lib/iiif_print/engine.rb

@@ -49,19 +49,6 @@ class Engine < ::Rails::Engine
       ::BlacklightIiifSearch::IiifSearchAnnotation.prepend(IiifPrint::BlacklightIiifSearch::AnnotationDecorator)
       Hyrax::Actors::FileSetActor.prepend(IiifPrint::Actors::FileSetActorDecorator)
 
-      # Extending the presenter to the base url which includes the protocol.
-      # We need the base url to render the facet links and normalize the interface.
-      Hyrax::IiifManifestPresenter.send(:attr_accessor, :base_url)
-      Hyrax::IiifManifestPresenter::DisplayImagePresenter.send(:attr_accessor, :base_url)
-      # Extending this class because there is an #ability= but not #ability and this definition
-      # mirrors the Hyrax::IiifManifestPresenter#ability.
-      module Hyrax::IiifManifestPresenter::DisplayImagePresenterDecorator
-        def ability
-          @ability ||= NullAbility.new
-        end
-      end
-      Hyrax::IiifManifestPresenter::DisplayImagePresenter.prepend(Hyrax::IiifManifestPresenter::DisplayImagePresenterDecorator)
-
       Hyrax.config do |config|
         config.callback.set(:after_create_fileset) do |file_set, user|
           IiifPrint.config.handle_after_create_fileset(file_set, user)

spec/presenters/iiif_print/iiif_manifest_presenter_behavior_spec.rb

@@ -17,31 +17,53 @@
     end
   end
 
-  # this method is inside of the DisplayImagePresenterBehavior module
-  describe '#display_image' do
+  context 'with IIIF external support' do
     let(:presenter) { Hyrax::IiifManifestPresenter::DisplayImagePresenter.new(solr_document) }
     let(:id) { 'abc123' }
+    let(:url) { 'external_iiif_url' }
+    let(:iiif_info_url_builder) { ->(file_id, base_url) { "#{base_url}/#{file_id}" } }
 
-    context 'when serverless_iiif is enabled' do
-      let(:url) { 'serverless_iiif_url' }
+    before { allow(solr_document).to receive(:image?).and_return(true) }
 
-      it 'renders a serverless url' do
+    context 'when external iiif is enabled' do
+      before do
         allow(ENV).to receive(:[])
-        allow(ENV).to receive(:[]).with('SERVERLESS_IIIF_URL').and_return(url)
+        allow(ENV).to receive(:[]).with('EXTERNAL_IIIF_URL').and_return(url)
         allow(presenter).to receive(:latest_file_id).and_return(id)
-        expect(presenter.display_image.iiif_endpoint.url).to eq "#{url}/#{id}"
-        expect(presenter.display_image.iiif_endpoint.profile).to eq "http://iiif.io/api/image/2/level2.json"
       end
-    end
 
-    context 'when serverless_iiif is not enabled' do
-      let(:iiif_info_url_builder) { ->(file_id, base_url) { "#{base_url}/#{file_id}" } }
+      describe '#display_image' do
+        it 'renders a external url' do
+          expect(presenter.display_image.iiif_endpoint.url).to eq "#{url}/#{id}"
+          expect(presenter.display_image.iiif_endpoint.profile).to eq "http://iiif.io/api/image/2/level2.json"
+        end
+      end
+
+      describe '#display_content' do
+        it 'renders a external url' do
+          expect(presenter.display_content.iiif_endpoint.url).to eq "#{url}/#{id}"
+          expect(presenter.display_content.iiif_endpoint.profile).to eq "http://iiif.io/api/image/2/level2.json"
+        end
+      end
+    end
 
-      it 'does not render a serverless url' do
+    context 'when external iiif is not enabled' do
+      before do
         allow(presenter).to receive(:latest_file_id).and_return(id)
         allow(Hyrax.config).to receive(:iiif_image_server?).and_return(true)
         allow(Hyrax.config).to receive(:iiif_info_url_builder).and_return(iiif_info_url_builder)
-        expect(presenter.display_image.iiif_endpoint.url).to eq "localhost/#{id}"
+      end
+
+      describe '#display_image' do
+        it 'does not render a external url' do
+          expect(presenter.display_image.iiif_endpoint.url).to eq "localhost/#{id}"
+        end
+      end
+
+      describe '#display_content' do
+        it 'does not render a external url' do
+          expect(presenter.display_content.iiif_endpoint.url).to eq "localhost/#{id}"
+        end
       end
     end
   end