USE-188: Responsive behavior for tab bar

app/assets/stylesheets/application.css.scss

@@ -19,6 +19,7 @@
 @import "partials/_record";
 @import "partials/_search";
 @import "partials/_shared";
+@import "partials/_source_tabs";
 @import "partials/_results";
 @import "partials/_loading_spinner";
 @import "partials/_suggestion-panel";

app/assets/stylesheets/partials/_search.scss

@@ -214,52 +214,6 @@
   color: #fff;
 }
 
-/* =========== */
-/* New Tab Bar */
-/* =========== */
-
-#tabs {
-  margin-top: 0;
-
-  ul {
-    list-style-type: none;
-    padding: 0;
-    margin: 0;
-    display: flex;
-    gap: 4px;
-  }
-
-  a {
-    padding: 12px 20px 16px;
-    background-color: transparent;
-    display: inline-block;
-    border: 2px solid transparent;
-    border-bottom: 0;  
-
-    @include searchUnderlinedLinks;
-
-    &:hover {
-      border-color: $color-gray-700;
-      background-color: $color-gray-900;
-      color: $color-text-oncolor;
-    }
-
-    &.active {
-      background-color: $color-white;
-      color: $color-text-primary;
-      text-decoration: none;
-
-      &:hover {
-        color: $color-text-primary;
-        border-color: transparent;
-      }
-    }
-
-
-  }
-
-}
-
 /* ============== */
 /* Search Actions */
 /* ============== */

app/assets/stylesheets/partials/_source_tabs.scss

@@ -0,0 +1,103 @@
+/* ============================ */
+/* Source Tab Bar in USE Search */
+/* ============================ */
+
+#tabs {
+  margin-top: 0;
+  position: relative;
+
+  // Graceful degradation when JS is not enabled
+  &:not(.has-js) {
+    overflow-x: auto;
+    -webkit-overflow-scrolling: touch;  
+  }
+
+  // Display styles for the main tab bar
+  ul.primary {
+    list-style-type: none;
+    padding: 0;
+    margin: 0;
+    display: flex;
+    gap: 4px;
+  }
+
+  li {
+
+    &.--hidden {
+      display: none;
+    }
+
+  }
+
+  a, button {
+    padding: 12px 20px 16px;
+    background-color: transparent;
+    display: inline-block;
+    border: 2px solid transparent;
+    border-bottom: 0;  
+    white-space: nowrap;
+
+    @include searchUnderlinedLinks;
+
+    &:hover {
+      border-color: $color-gray-700;
+      background-color: $color-gray-900;
+      color: $color-text-oncolor;
+    }
+
+    &.active {
+      background-color: $color-white;
+      color: $color-text-primary;
+      text-decoration: none;
+
+      &:hover {
+        color: $color-text-primary;
+        border-color: transparent;
+      }
+    }
+
+  }
+
+  // Swap the icon to chevron-up when menu is open
+  button[aria-expanded="true"] {
+
+    i::before {
+      content: '\f077';
+    }
+
+  }
+
+  // Display styles for the dropdown menu under the "More" button
+  ul.-secondary {
+    width: 100%;
+    display: none;
+    position: absolute;
+    top: 100%;
+    right: 0;
+    list-style-type: none;
+    padding: 0;
+    margin: 0;
+    z-index: 999;
+
+    li {
+      width: 100%;
+
+      a {
+        background-color: $color-gray-950;
+        width: 100%;
+
+        &:hover {
+          border-color: $color-gray-950;
+          background-color: $color-gray-900;
+        }
+      }
+
+    }
+
+  }
+
+  &.--show-secondary .-secondary {
+    display: block;
+  }
+
+}

app/javascript/loading_spinner.js

@@ -68,6 +68,10 @@ document.addEventListener('click', function(event) {
 
   // Handle tab clicks
   if (clickedElement.closest('.tab-navigation')) {
+
+    // If the element is NOT a link, don't show the spinner
+    if (clickedElement.nodeName !== "A") { return; }
+
     const clickedParams = new URLSearchParams(clickedElement.search);
     const newTab = clickedParams.get('tab');
 

app/javascript/source_tabs.js

@@ -0,0 +1,89 @@
+// ===========================================================================
+// RESPONSIVE TAB BAR LOGIC WITH GRACEFUL DEGRADATION
+// Source: https://css-tricks.com/container-adapting-tabs-with-more-button/
+// ===========================================================================
+
+// Store references to relevant selectors
+const container = document.querySelector('#tabs')
+const primary = container.querySelector('.primary')
+const primaryItems = container.querySelectorAll('.primary > li:not(.-more)')
+
+// Add a class to turn off graceful degradation style
+container.classList.add('has-js')
+
+// insert "more" button and duplicate the original tab bar items
+primary.insertAdjacentHTML('beforeend', `
+  <li class="-more">
+    <button type="button" aria-haspopup="true" aria-expanded="false" aria-controls="more-options">
+      More <i class="fa-light fa-chevron-down"></i>
+    </button>
+    <ul class="-secondary" id="more-options" aria-label="More options">
+      ${primary.innerHTML}
+    </ul>
+  </li>
+`)
+const secondary = container.querySelector('.-secondary')
+const secondaryItems = secondary.querySelectorAll('li')
+const allItems = container.querySelectorAll('li')
+const moreLi = primary.querySelector('.-more')
+const moreBtn = moreLi.querySelector('button')
+
+// When the more button is clicked, toggle classes to indicate the secondary menu is open
+moreBtn.addEventListener('click', (e) => {
+  e.preventDefault()
+  container.classList.toggle('--show-secondary')
+  moreBtn.setAttribute('aria-expanded', container.classList.contains('--show-secondary'))
+})
+
+// adapt tabs
+const doAdapt = () => {
+
+  // reveal all items for the calculation
+  allItems.forEach((item) => {
+    item.classList.remove('--hidden')
+  })
+
+  // hide items that won't fit in the Primary tab bar
+  let stopWidth = moreBtn.offsetWidth
+  let hiddenItems = []
+  const primaryWidth = primary.offsetWidth
+  primaryItems.forEach((item, i) => {
+    if(primaryWidth >= stopWidth + item.offsetWidth) {
+      stopWidth += item.offsetWidth
+    } else {
+      item.classList.add('--hidden')
+      hiddenItems.push(i)
+    }
+  })
+
+  // toggle the visibility of More button and items in Secondary menu
+  if(!hiddenItems.length) {
+    moreLi.classList.add('--hidden')
+    container.classList.remove('--show-secondary')
+    moreBtn.setAttribute('aria-expanded', false)
+  }
+  else {  
+    secondaryItems.forEach((item, i) => {
+      if(!hiddenItems.includes(i)) {
+        item.classList.add('--hidden')
+      }
+    })
+  }
+}
+
+// Adapt the tabs to fit the viewport
+doAdapt() // immediately on load
+window.addEventListener('resize', doAdapt) // on window resize
+
+// hide Secondary menu on the outside click
+document.addEventListener('click', (e) => {
+  let el = e.target
+  while(el) {
+    if(el === moreBtn) {
+      return;
+    }
+    el = el.parentNode
+  }
+  container.classList.remove('--show-secondary')
+  moreBtn.setAttribute('aria-expanded', false)
+})

app/views/search/_source_tabs.html.erb

@@ -1,23 +1,25 @@
   <!-- Tab Navigation -->
   <nav id="tabs" class="tab-navigation" aria-label="Result type navigation">
-    <ul>
+    <ul class="primary">
       <li><%= link_to_tab("All") %></li>
 
       <% if Feature.enabled?(:tab_primo_all) %>
         <li><%= link_to_tab("Primo", "Articles and Catalog") %></li>
       <% end %>
 
       <li><%= link_to_tab("cdi", "Articles") %></li>
-      <li><%= link_to_tab("alma", "Catalog") %></li>
+      <li><%= link_to_tab("alma", "Books and media") %></li>
 
       <% if Feature.enabled?(:tab_timdex_all) %>
         <li><%= link_to_tab("TIMDEX") %></li>
       <% end %>
       <% if Feature.enabled?(:tab_timdex_alma) %>
         <li><%= link_to_tab("timdex_alma", "Alma (TIMDEX)") %></li>
       <% end %>
+      <li><%= link_to_tab("aspace", "MIT archives") %></li>
       <li><%= link_to_tab("Website") %></li>
-      <li><%= link_to_tab("aspace", "Archival materials") %></li>
     </ul>
   </nav>
+
+  <%= javascript_include_tag "source_tabs" %>