Forces UTF-8 encoding on ALTO XML.

app/controllers/catalog_controller.rb

@@ -19,6 +19,7 @@ def self.modified_field
 
   # CatalogController-scope behavior and configuration for BlacklightIiifSearch
   include BlacklightIiifSearch::Controller
+  skip_before_action :authenticate_user!, only: :iiif_search
 
   configure_blacklight do |config|
     # configuration for Blacklight IIIF Content Search

app/models/file_set.rb

@@ -87,13 +87,14 @@ def preferred_file
     end
   end
 
+  # The two methods below err when storing text in Solr, so forcing UTF-8 encoding removes errant text (most likely ASCII).
   def alto_xml
-    return extracted&.content if extracted&.file_name&.first&.include?('.xml')
+    return extracted&.content&.force_encoding('UTF-8')&.encode("UTF-8", invalid: :replace, replace: "") if extracted&.file_name&.first&.include?('.xml')
     nil
   end
 
   def transcript_text
-    transcript_file&.content&.force_encoding('UTF-8') if transcript_file&.file_name&.first&.include?('.txt')
+    transcript_file&.content&.force_encoding('UTF-8')&.encode("UTF-8", invalid: :replace, replace: "") if transcript_file&.file_name&.first&.include?('.txt')
   end
 
   private

app/views/manifest/manifest.json.jbuilder

@@ -15,7 +15,7 @@ end
 #   within the Work to activate, but each text-optimized FileSet's alto_xml_tesi,
 #   transcript_text_tesi, and is_page_of_ssi fields must also be indexed for normal
 #   searching functions.
-if @solr_doc['all_text_tsimv'].present?
+if @image_concerns.any? { |id| SolrDocument&.find(id)&.[]('alto_xml_tesi')&.present? }
   json.service do
     json.child! do
       json.set! :@context, 'http://iiif.io/api/search/0/context.json'

spec/views/manifest/manifest.json.jbuilder_spec.rb

@@ -96,10 +96,9 @@
     expect(work.file_sets.count).to eq 5
   end
 
-  context 'when all_text_tsimv is present' do
-    let(:solr_document) { SolrDocument.new(attributes.merge('all_text_tsimv' => 'So much text!')) }
-
+  context 'when @image_concerns contains values in alto_xml_tesi' do
     it 'renders a IIIF Search service' do
+      allow(image_concerns).to receive(:any?).and_return(true)
       render
       parsed_rendered_manifest = JSON.parse(rendered)