add an access_panels component for linking to the same object in other user facing systems

app/components/access_panels/other_listings_component.html.erb

@@ -0,0 +1,11 @@
+<%= render @layout.new do |component| %>
+  <% component.with_title { 'Also listed in' } %>
+  <% component.with_body do %>
+    <% if earthworks_url.present? %>
+      <p><%= link_to('Earthworks', earthworks_url) %></p>
+    <% end %>
+    <% purl_links.each do |purl_link| %>
+      <p><%= purl_link %></p>
+    <% end %>
+  <% end %>
+<% end %>

app/components/access_panels/other_listings_component.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module AccessPanels
+  class OtherListingsComponent < AccessPanels::Base
+    def render?
+      earthworks_url.present? || purls.present?
+    end
+
+    def earthworks_url
+      @earthworks_url ||= construct_earthworks_url
+    end
+
+    # @return [Array<String>] a tags representing PURL links
+    def purl_links
+      @purl_links ||=
+        if purls.size > 1 # text of the link is the actual URL if there is more than one unique URL, so there aren't multiple links with the same title
+          purls.map { |purl| link_to(purl, purl) }
+        elsif purls.size == 1
+          Array(link_to('Stanford Digital Repository', purls.first))
+        else
+          []
+        end
+    end
+
+    private
+
+    # @return [Array<String>] URLs representing links to PURL, whether specified in MARC or MODS, and de-duped, e.g. ["https://purl.stanford.edu/hj948rn6493"]
+    def purls
+      @purls ||= (mods_purls + marc_managed_purls).uniq
+    end
+
+    # @return [Array<String>] URLs representing links to other locations, extracted from MODS metadata, e.g. ["https://purl.stanford.edu/hj948rn6493"]
+    def mods_purls
+      Array(document['url_fulltext']).find_all { |str| str.start_with?(Settings.PURL_EMBED_RESOURCE) }
+    end
+
+    # @return [Array<String>] URLs representing links to other locations, extracted from MARC metadata, e.g. ["https://purl.stanford.edu/hj948rn6493"]
+    def marc_managed_purls
+      document.marc_links.managed_purls.filter_map(&:href) # filter_map because href can be nil, at least in fixture data
+    end
+
+    def construct_earthworks_url
+      return nil unless document['dor_content_type_ssi'] == 'geo'
+
+      # * Hardcoding this simple URL format because it should work for all things it'd apply to (anything released to both SW and EW should be a Stanford object)
+      # * Using Kernel.format because there's a clashing ViewComponent::Base#format, so the namespacing is needed
+      Kernel.format('https://%<hostname>s/catalog/stanford-%<bare_druid>s', hostname: Settings.earthworks.hostname, bare_druid: document.druid)
+    end
+  end
+end

app/views/catalog/record/_metadata_panels.html.erb

@@ -11,6 +11,7 @@
 
   <% potential_context = capture do %>
     <%= render AccessPanels::ExhibitComponent.new(document: document) %>
+    <%= render AccessPanels::OtherListingsComponent.new(document: document) %>
   <% end %>
 
   <% if context.present? || potential_context.present? %>

app/views/catalog/record/_mods_bibliographic.html.erb

@@ -24,6 +24,6 @@
   <%= render ModsDisplay::FieldComponent.new(field: identifier, label_html_attributes: { class: 'col-md-3' }, value_html_attributes: { class: 'col-md-9' }) %>
 <% end %>
 
-<% document.mods.location.each do |location| %>
+<% document.mods.location.reject { |location| location.values.detect { |loc| /href=.#{Settings.PURL_EMBED_RESOURCE}/.match?(loc) } }.each do |location| %>
   <%= render ModsDisplay::FieldComponent.new(field: location, label_html_attributes: { class: 'col-md-3' }, value_html_attributes: { class: 'col-md-9' }) %>
 <% end %>

config/settings.yml

@@ -275,3 +275,6 @@ folio_unrequestable_statuses:
   - Unavailable
   - Unknown
   - Withdrawn
+
+earthworks:
+  hostname: 'earthworks.stanford.edu'

spec/components/access_panels/other_listings_component_spec.rb

@@ -0,0 +1,94 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe AccessPanels::OtherListingsComponent, type: :component do
+  include MarcMetadataFixtures
+
+  let(:component) { described_class.new(document:) }
+
+  let(:document_hash) { { id: '123', dor_content_type_ssi: 'notgeo' } }
+  let(:document) { SolrDocument.new(document_hash) }
+
+  subject(:page) { render_inline(component) }
+
+  it 'does not render if the item neither is released to Earthworks nor has a PURL' do
+    page
+    expect(rendered_content).to eq ""
+  end
+
+  context 'there is a PURL specified in the MARC' do
+    let(:document_hash) do
+      {
+        id: 'hj948rn6493',
+        marc_links_struct: [
+          { href: 'https://purl.stanford.edu/hj948rn6493', managed_purl: true }
+        ]
+      }
+    end
+
+    it 'displays a link to the PURL' do
+      expect(page).to have_link('Stanford Digital Repository', href: 'https://purl.stanford.edu/hj948rn6493')
+    end
+  end
+
+  context 'there is a PURL specified in the MODS' do
+    let(:document_hash) { { id: 'bd285ct9109', url_fulltext: 'https://purl.stanford.edu/hj948rn6493' } }
+
+    it 'displays a link to the PURL' do
+      expect(page).to have_link('Stanford Digital Repository', href: 'https://purl.stanford.edu/hj948rn6493')
+    end
+  end
+
+  context 'the same PURL is specified in both MARC and MODS' do
+    let(:document_hash) do
+      {
+        id: 'hj948rn6493',
+        url_fulltext: 'https://purl.stanford.edu/hj948rn6493',
+        marc_links_struct: [
+          { href: 'https://purl.stanford.edu/hj948rn6493', managed_purl: true }
+        ]
+      }
+    end
+
+    it 'displays a single link to the PURL' do
+      expect(page).to have_link('Stanford Digital Repository', href: 'https://purl.stanford.edu/hj948rn6493')
+      expect(page).to have_css('a', count: 1)
+    end
+  end
+
+  context 'MODS and MARC specify different PURLs' do
+    let(:document_hash) do
+      {
+        id: '123',
+        url_fulltext: 'https://purl.stanford.edu/bc123df4567',
+        marc_links_struct: [
+          { href: 'https://purl.stanford.edu/gh890jk9876', managed_purl: true }
+        ]
+      }
+    end
+
+    it 'displays a single link to the PURL' do
+      expect(page).to have_link('https://purl.stanford.edu/bc123df4567', href: 'https://purl.stanford.edu/bc123df4567')
+      expect(page).to have_link('https://purl.stanford.edu/gh890jk9876', href: 'https://purl.stanford.edu/gh890jk9876')
+      expect(page).to have_css('a', count: 2)
+    end
+  end
+
+  context 'the object has been released to Earthworks' do
+    let(:document_hash) { { id: 'bd285ct9109', druid: 'bd285ct9109', dor_content_type_ssi: 'geo' } }
+
+    it 'displays a link to Earthworks' do
+      expect(page).to have_link('Earthworks', href: "https://#{Settings.earthworks.hostname}/catalog/stanford-bd285ct9109")
+    end
+  end
+
+  context 'the object has been released to Earthworks and it has a PURL' do
+    let(:document_hash) { { druid: 'bd285ct9109', url_fulltext: 'https://purl.stanford.edu/bd285ct9109', dor_content_type_ssi: 'geo' } }
+
+    it 'displays a link to the PURL and a link to Earthworks' do
+      expect(page).to have_link('Stanford Digital Repository', href: 'https://purl.stanford.edu/bd285ct9109')
+      expect(page).to have_link('Earthworks', href: "https://#{Settings.earthworks.hostname}/catalog/stanford-bd285ct9109")
+    end
+  end
+end