Merge pull request #1469 from sul-dlss/vtt

Use VTT transcript

app/models/embed/purl/resource.rb

@@ -48,6 +48,11 @@ def primary_file
       def thumbnail
         files.find(&:thumbnail?)
       end
+
+      # @return [ResourceFile]
+      def vtt
+        files.find(&:vtt?)
+      end
     end
   end
 end

app/models/embed/purl/resource_file.rb

@@ -43,6 +43,14 @@ def thumbnail?
         Settings.resource_types_that_contain_thumbnails.include?(resource.type)
       end
 
+      def vtt
+        resource.files.find(&:vtt?)
+      end
+
+      def vtt?
+        mimetype == 'text/vtt'
+      end
+
       def pdf?
         mimetype == 'application/pdf'
       end

lib/embed/media_tag.rb

@@ -4,6 +4,7 @@ module Embed
   # Utility class to handle generating HTML <video> and <audio> tags
   # Currently, MPEG-DASH is used at the <video> element level (in a data attribute to be picked up by javascript)
   # and HLS is used as a <source> within the <video> or <audio> tag.
+  # rubocop:disable Metrics/ClassLength
   class MediaTag
     SUPPORTED_MEDIA_TYPES = %i[audio video].freeze
 
@@ -51,6 +52,7 @@ def media_element(file, type)
             class="sul-embed-media-file #{'sul-embed-many-media' if many_primary_files?}"
             height="100%">
             #{enabled_streaming_sources(file)}
+            #{transcript(file)}
           </#{type}>
         HTML
       end
@@ -91,6 +93,14 @@ def enabled_streaming_sources(file)
       end.join
     end
 
+    def transcript(file)
+      return unless file.vtt
+
+      <<~HTML
+        <track default src="#{viewer.stacks_url}/#{file.vtt.title}" />
+      HTML
+    end
+
     def many_primary_files?
       primary_files_count > 1
     end
@@ -165,4 +175,5 @@ def authentication_url(file)
       Settings.streaming.auth_url % attributes
     end
   end
+  # rubocop:enable Metrics/ClassLength
 end

spec/fixtures/purl_fixtures.rb

@@ -963,6 +963,32 @@ def single_video_purl
     XML
   end
 
+  def video_purl_with_vtt
+    <<-XML
+      <publicObject>
+        <identityMetadata>
+          <objectLabel>Title of the single video</objectLabel>
+        </identityMetadata>
+        <contentMetadata type="media">
+          <resource sequence="1" id="abc123_1" type="video">
+            <file id="abc_123.mp4" mimetype="video/mp4" size="152000000"></file>
+            <file id="abc_123_cap.webvtt" mimetype="text/vtt" size="176218"></file>
+          </resource>
+        </contentMetadata>
+        <rightsMetadata>
+          <access type="read">
+            <machine>
+              <location>spec</location>
+            </machine>
+          </access>
+        </rightsMetadata>
+        <oai_dc:dc xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:dc="http://purl.org/dc/elements/1.1/">
+          <dc:title>title of video with vtt</dc:title>
+        </oai_dc>
+      </publicObject>
+    XML
+  end
+
   def video_purl
     <<-XML
       <publicObject>

spec/lib/embed/media_tag_spec.rb

@@ -10,7 +10,8 @@
   let(:purl) { video_purl }
   let(:viewer) do
     instance_double(Embed::Viewer::Media,
-                    purl_object: Embed::Purl.new('druid'))
+                    purl_object: Embed::Purl.new('druid'),
+                    stacks_url: '/file/druid')
   end
 
   let(:subject_klass) { described_class.new(viewer) }
@@ -231,6 +232,14 @@
       end
     end
 
+    describe '#transcript' do
+      before { stub_purl_response_with_fixture(video_purl_with_vtt) }
+
+      it 'has a track element' do
+        expect(subject).to have_css('track[src="/file/druid/abc_123_cap.webvtt"]')
+      end
+    end
+
     describe '#previewable_element' do
       before { stub_purl_response_with_fixture(purl) }
 

spec/models/embed/purl/resource_file_spec.rb

@@ -276,4 +276,24 @@
       end
     end
   end
+
+  describe '#vtt?' do
+    subject { file.vtt? }
+
+    context 'when it is a vtt transcript' do
+      let(:file) { Embed::Purl.new('12345').contents.first.files.second }
+
+      before { stub_purl_response_with_fixture(video_purl_with_vtt) }
+
+      it { is_expected.to be true }
+    end
+
+    context 'when it is not a vtt transcript' do
+      let(:file) { Embed::Purl.new('12345').contents.first.files.first }
+
+      before { stub_purl_response_with_fixture(single_video_purl) }
+
+      it { is_expected.to be false }
+    end
+  end
 end

spec/models/embed/purl/resource_spec.rb

@@ -49,4 +49,24 @@
       expect(Embed::Purl.new('12345').contents.first.files.all?(Embed::Purl::ResourceFile)).to be true
     end
   end
+
+  describe '#vtt' do
+    let(:resource) { Embed::Purl.new('12345').contents.first }
+
+    context 'when it has a vtt transcript' do
+      subject { resource.vtt.title }
+
+      before { stub_purl_response_with_fixture(video_purl_with_vtt) }
+
+      it { is_expected.to eq 'abc_123_cap.webvtt' }
+    end
+
+    context 'when it does not have a vtt transcript' do
+      subject { resource.vtt }
+
+      before { stub_purl_response_with_fixture(single_video_purl) }
+
+      it { is_expected.to be_nil }
+    end
+  end
 end