Downgrade css to prevent older browsers displaying faulty views

public/css/app.css

@@ -68,12 +68,12 @@ button,
   box-shadow: 0 .15rem .5rem rgba(0, 0, 0, .2);
 }
 
-.app-page > header:has(.back-button) {
+.app-page > header.has-back-button {
   grid-template-columns: var(--icon-button-size) minmax(0, 1fr) var(--icon-button-size);
   gap: .5rem;
 }
 
-.app-page > header:has(.back-button)::after {
+.app-page > header.has-back-button::after {
   content: "";
 }
 

public/index.html

@@ -5,7 +5,9 @@
   <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover">
   <meta name="theme-color" content="#315d3a">
   <title>Wegwichtel</title>
-  <link rel="stylesheet" href="css/bootstrap.css?v=0.12.11">
+  <link rel="stylesheet" href="css/bootstrap.css?v=0.12.12">
+  <link rel="stylesheet" href="vendor/jquery-ui/jquery-ui-1.14.2.min.css?v=0.12.12">
+  <link rel="stylesheet" href="css/app.css?v=0.12.12">
 </head>
 <body>
   <div id="bootstrap-screen" aria-live="polite" aria-busy="true">
@@ -41,7 +43,9 @@
 
         <section>
           <h2>Routen in deiner Nähe</h2>
-          <ul id="nearby-route-list" class="route-list" aria-live="polite"></ul>
+          <ul id="nearby-route-list" class="route-list" aria-live="polite">
+            <li><p>Routen werden geladen …</p></li>
+          </ul>
         </section>
 
         <section>
@@ -58,14 +62,16 @@
             <button id="clear-route-search" type="button">Suche leeren</button>
           </div>
 
-          <p id="all-routes-summary" aria-live="polite"></p>
-          <ul id="all-route-list" class="route-list" aria-live="polite"></ul>
+          <p id="all-routes-summary" aria-live="polite">Routen werden geladen …</p>
+          <ul id="all-route-list" class="route-list" aria-live="polite">
+            <li><p>Routen werden geladen …</p></li>
+          </ul>
         </section>
       </div>
     </section>
 
     <section id="route-page" class="app-page" hidden>
-      <header>
+      <header class="has-back-button">
         <button class="back-button" type="button" data-page-target="#routes-page" aria-label="Zurück zur Routenauswahl" title="Zurück zur Routenauswahl">
           <img src="images/icons/back.svg" alt="">
         </button>
@@ -101,7 +107,7 @@
     </section>
 
     <section id="poi-page" class="app-page" hidden>
-      <header>
+      <header class="has-back-button">
         <button class="back-button" type="button" data-page-target="#route-page" aria-label="Zurück zur Route" title="Zurück zur Route">
           <img src="images/icons/back.svg" alt="">
         </button>
@@ -145,6 +151,6 @@
     </footer>
   </main>
 
-  <script src="js/bootstrap-loader.js?v=0.12.11"></script>
+  <script src="js/bootstrap-loader.js?v=0.12.12"></script>
 </body>
 </html>

public/js/app.js

@@ -66,12 +66,13 @@
 
   function renderRouteItems(listSelector, routes, emptyText) {
     const list = $(listSelector).empty();
-    if (!routes.length) {
+    const items = Array.isArray(routes) ? routes.filter(Boolean) : [];
+    if (!items.length) {
       list.append(`<li><p>${escapeHtml(emptyText)}</p></li>`);
       return;
     }
 
-    routes.forEach(route => {
+    items.forEach(route => {
       const proximity = route.proximityM == null
         ? ''
         : `<small>${escapeHtml(ns.Distance.format(route.proximityM))} entfernt</small>`;
@@ -89,18 +90,20 @@
   }
 
   function renderRoutes() {
+    const routes = Array.isArray(state.routes) ? state.routes.filter(Boolean) : [];
     const radiusM = ns.Config.routeRadiusKm * 1000;
     const nearbyRoutes = state.position
-      ? state.routes
+      ? routes
         .filter(route => route.proximityM != null && route.proximityM <= radiusM)
+        .slice()
         .sort((a, b) => a.proximityM - b.proximityM)
       : [];
 
     const searchTerm = normalizeSearch($('#route-search').val());
-    const allRoutes = state.routes
+    const allRoutes = routes
       .filter(route => routeMatchesSearch(route, searchTerm))
       .slice()
-      .sort((a, b) => a.name.localeCompare(b.name, 'de'));
+      .sort((a, b) => String(a.name ?? '').localeCompare(String(b.name ?? ''), 'de'));
 
     const nearbyEmptyText = state.position
       ? `Keine Route im Umkreis von ${ns.Config.routeRadiusKm} km gefunden. Wähle unten eine beliebige Route aus.`
@@ -115,13 +118,15 @@
 
     $('#all-routes-summary').text(
       searchTerm
-        ? `${allRoutes.length} von ${state.routes.length} Routen gefunden.`
-        : `${state.routes.length} Routen verfügbar.`
+        ? `${allRoutes.length} von ${routes.length} Routen gefunden.`
+        : `${routes.length} Routen verfügbar.`
     );
   }
 
   function initializeRouteSearch() {
     const input = $('#route-search');
+    if (!input.length || typeof input.autocomplete !== 'function') return;
+
     input.autocomplete({
       minLength: 0,
       source(request, response) {
@@ -498,6 +503,43 @@
     }
   }
 
+  function routesFromResponse(response) {
+    if (!Array.isArray(response?.routes)) {
+      throw new Error('Die Routen-API hat keine gültige Routenliste geliefert.');
+    }
+    return response.routes.filter(route => route && route.id != null && route.name != null);
+  }
+
+  function updateRouteProximity(position) {
+    state.routes = state.routes.map(route => ({
+      ...route,
+      proximityM: route.start ? ns.Distance.meters(position, route.start) : null
+    }));
+  }
+
+  async function initializeLocation(context) {
+    try {
+      const position = await ns.Geo.current();
+      state.position = position;
+      updateRouteProximity(position);
+      $('#location-hint').text(
+        `Standort ermittelt (Genauigkeit ${Math.round(position.accuracy)} m). `
+        + `Nahe Routen werden bis ${ns.Config.routeRadiusKm} km empfohlen.`
+      );
+    } catch (error) {
+      $('#location-hint').text(
+        `Standort nicht verfügbar: ${error.message}. Alle Routen können weiterhin ausgewählt werden.`
+      );
+    } finally {
+      context.markStep('location', 'done');
+      renderRoutes();
+    }
+  }
+
+  function restoreRouteLists() {
+    if (state.routes.length) renderRoutes();
+  }
+
   function bindEvents() {
     $(document).on('input', '#route-search', renderRoutes);
 
@@ -546,6 +588,11 @@
       const page = event.state?.page || '#routes-page';
       navigate(page, { updateHistory: false, instant: true });
     });
+
+    globalThis.addEventListener('pageshow', restoreRouteLists);
+    document.addEventListener('visibilitychange', () => {
+      if (document.visibilityState === 'visible') restoreRouteLists();
+    });
   }
 
   ns.App = {
@@ -557,31 +604,15 @@
       context.markStep('server', 'done');
 
       const response = await ns.Api.routes(null);
-      state.routes = response.routes;
+      state.routes = routesFromResponse(response);
       context.markStep('routes', 'done');
 
-      try {
-        const position = await ns.Geo.current();
-        state.position = position;
-        $('#location-hint').text(
-          `Standort ermittelt (Genauigkeit ${Math.round(position.accuracy)} m). `
-          + `Nahe Routen werden bis ${ns.Config.routeRadiusKm} km empfohlen.`
-        );
-        state.routes = state.routes.map(route => ({
-          ...route,
-          proximityM: route.start ? ns.Distance.meters(position, route.start) : null
-        }));
-      } catch (error) {
-        $('#location-hint').text(
-          `Standort nicht verfügbar: ${error.message}. Alle Routen können weiterhin ausgewählt werden.`
-        );
-      }
-
-      context.markStep('location', 'done');
-      initializeRouteSearch();
       renderRoutes();
+      initializeRouteSearch();
       updateRouteControls();
       hideNavigation();
+
+      void initializeLocation(context);
     }
   };
 }(globalThis.Wegwichtel, globalThis.jQuery));

public/js/bootstrap-loader.js

@@ -1,7 +1,7 @@
 (function () {
   'use strict';
 
-  const versions = Object.freeze({ app: '0.12.11', jquery: '4.0.0', jqueryUi: '1.14.2' });
+  const versions = Object.freeze({ app: '0.12.12', jquery: '4.0.0', jqueryUi: '1.14.2' });
   const steps = ['jquery', 'jquery-ui', 'modules', 'server', 'routes', 'location'];
   const progress = document.getElementById('bootstrap-progress');
   const errorBox = document.getElementById('bootstrap-error');
@@ -31,17 +31,6 @@
     });
   }
 
-  function loadStyle(href) {
-    return new Promise((resolve, reject) => {
-      const link = document.createElement('link');
-      link.rel = 'stylesheet';
-      link.href = versioned(href);
-      link.onload = resolve;
-      link.onerror = () => reject(new Error(`Stylesheet konnte nicht geladen werden: ${href}`));
-      document.head.appendChild(link);
-    });
-  }
-
   function initializeJqueryUi() {
     const $ = globalThis.jQuery;
     $('#bootstrap-retry').button({ icon: 'ui-icon-refresh' });
@@ -62,8 +51,6 @@
       );
       mark('jquery', 'done');
 
-      await loadStyle(`vendor/jquery-ui/jquery-ui-${versions.jqueryUi}.min.css`);
-      await loadStyle('css/app.css');
       await loadScript(
         `vendor/jquery-ui/jquery-ui-${versions.jqueryUi}.min.js`,
         () => globalThis.jQuery?.ui?.version === versions.jqueryUi