Define new helper for tab links, with aria

app/assets/stylesheets/partials/_loading_spinner.scss

@@ -8,7 +8,7 @@
 }
 
 // Pagination overlay when loading
-[busy]:not([no-spinner]) {
+.spinner {
   position: relative;
   min-height: 400px;
   display: block;

app/helpers/search_helper.rb

@@ -22,6 +22,19 @@ def link_to_result(result)
     end
   end
 
+  def link_to_tab(target)
+    if @active_tab == target.downcase
+      link_to target, results_path(params.permit(:q, :per_page, :booleanType, :tab).merge(tab: target.downcase)),
+        aria: { current: "page" },
+        class: "active tab-link",
+        data: { turbo_frame: "search-results", turbo_action: "advance" }
+    else
+      link_to target, results_path(params.permit(:q, :per_page, :booleanType, :tab).merge(tab: target.downcase)),
+        class: "tab-link",
+        data: { turbo_frame: "search-results", turbo_action: "advance" }
+    end
+  end
+
   def view_online(result)
     return unless result[:source_link].present?
 

app/javascript/loading_spinner.js

@@ -1,3 +1,19 @@
+// Update the tab UI to reflect the newly-requested state. This function is called
+// by a click event handler in the tab UI. It follows a two-step process:
+function swapTabs(new_target) {
+  // 1. Reset all tabs to base condition
+  document.querySelectorAll('.tab-link').forEach((tab) => {
+    tab.classList.remove('active');
+    tab.removeAttribute('aria-current');
+  });
+  // 2. Add "active" class and aria-current attribute to the newly-active tab link
+  const currentTabLink = document.querySelector(`.tab-link[href*="tab=${new_target}"]`);
+  if (currentTabLink) {
+    currentTabLink.classList.add('active');
+    currentTabLink.setAttribute('aria-current', 'page');
+  }
+}
+
 // Loading spinner behavior for pagination (Turbo Frame updates)
 document.addEventListener('turbo:frame-render', function(event) {
   if (window.pendingFocusAction === 'pagination') {
@@ -23,16 +39,8 @@ document.addEventListener('turbo:frame-render', function(event) {
       // console.log(`Updated tab input value to: ${queryParam}`);
     }
 
-    // update active tab styling
-    // remove active class from all tabs
-    document.querySelectorAll('.tab-link').forEach((tab) => {
-      tab.classList.remove('active');
-    });
-    // add active class to current tab
-    const currentTabLink = document.querySelector(`.tab-link[href*="tab=${queryParam}"]`);
-    if (currentTabLink) {
-      currentTabLink.classList.add('active');
-    }
+    // Remove the spinner now that things are ready
+    document.getElementById('search-results').classList.remove('spinner');
 
     // Clear the pending action
     window.pendingFocusAction = null;
@@ -51,7 +59,17 @@ document.addEventListener('click', function(event) {
 
   // Handle tab clicks
   if (clickedElement.closest('.tab-navigation')) {
+    const clickedParams = new URLSearchParams(clickedElement.search);
+    const newTab = clickedParams.get('tab');
+
+    // Throw the spinner on the search results immediately
+    document.getElementById('search-results').classList.add('spinner');
+
+    // Position the window at the top of the results
     window.scrollTo({ top: 0, behavior: 'smooth' });
+
+    swapTabs(newTab);
+
     window.pendingFocusAction = 'tab';
   }
 });

app/views/search/_source_tabs.html.erb

@@ -1,14 +1,8 @@
   <!-- Tab Navigation -->
   <nav id="tabs" class="tab-navigation" aria-label="Result type navigation">
     <ul>
-      <li>
-        <%= link_to "Primo", results_path(params.permit(:q, :per_page, :booleanType, :tab).merge(tab: 'primo')),
-                class: "tab-link #{'active' if @active_tab == 'primo'}",
-                data: { turbo_frame: "search-results", turbo_action: "advance" } %></li>  
-      <li>
-        <%= link_to "TIMDEX", results_path(params.permit(:q, :per_page, :booleanType, :tab).merge(tab: 'timdex')),
-                class: "tab-link #{'active' if @active_tab == 'timdex'}",
-                data: { turbo_frame: "search-results", turbo_action: "advance" } %></li>
+      <li><%= link_to_tab("Primo") %></li>
+      <li><%= link_to_tab("TIMDEX") %></li>
     </ul>
   </nav>
 

test/helpers/search_helper_test.rb

@@ -199,6 +199,27 @@ class SearchHelperTest < ActionView::TestCase
     assert_equal 'Sample Document Title', link_to_result(result)
   end
 
+  test 'link_to_tab builds a link without an aria attribute when that tab is not active' do
+    @active_tab = 'bar'
+    actual = link_to_tab('Foo')
+
+    assert_select Nokogiri::HTML::Document.parse( actual ), 'a' do |link|
+      assert_select '[class*=?]', 'active', count: 0
+      assert_select '[class*=?]', 'tab-link'
+      assert_select '[aria-current=?]', 'page', count: 0
+    end
+  end
+
+  test 'link_to_tab builds a link that includes an aria attribute when that tab is active' do
+    @active_tab = 'foo'
+    actual = link_to_tab('Foo')
+
+    assert_select Nokogiri::HTML::Document.parse( actual ), 'a' do |link|
+      assert_select link, '[class*=?]', 'active'
+      assert_select link, '[aria-current=?]', 'page', count: 1
+    end
+  end
+
   test 'primo_search_url generates correct Primo URL' do
     query = 'machine learning'
     expected_url = 'https://mit.primo.exlibrisgroup.com/discovery/search?query=any%2Ccontains%2Cmachine+learning&vid=01MIT_INST%3AMIT'