Books: Fortschritt-Konflikt via max() lösen — weiter = gewinnt (SW v14)

Der am weitesten gelesene Wert hat immer Vorrang:
- Server: scroll_fraction = max(neu, aktuell) — ein afk-Fenster bei 10%
  kann nicht mehr 80% überschreiben
- Client loadBookList: wenn lokaler Fortschritt > Server, wird gepusht
  und für die Anzeige verwendet (deckt Offline-Lesen ab)
- Pending-Flag-Logik entfernt — nicht mehr nötig dank max-Semantik
- saveReaderProgress(force=true): neuer force-Parameter schreibt
  Position unabhängig vom gespeicherten Maximum; Button ⚑ im
  Reader-Header für den Ausnahmefall "zurück-zum-Anfang"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

books/views.py

@@ -204,12 +204,21 @@ def save_progress(request, pk):
     if isinstance(raw_anchor, str) and re.fullmatch(r'\d{1,7}:\d(\.\d{1,6})?', raw_anchor):
         position_anchor = raw_anchor
 
+    force = bool(body.get('force', False))
+
     progress, _ = EBookProgress.objects.get_or_create(
         user=request.user,
         book=book,
     )
-    progress.scroll_fraction = scroll_fraction
+    # Always advance to the furthest-read position unless the client
-    progress.position_anchor = position_anchor
+    # explicitly forces a reset (e.g. "start over" button in the reader).
+    if force:
+        progress.scroll_fraction = scroll_fraction
+        progress.position_anchor = position_anchor
+    else:
+        if scroll_fraction >= progress.scroll_fraction:
+            progress.scroll_fraction = scroll_fraction
+            progress.position_anchor = position_anchor
     progress.save(update_fields=['scroll_fraction', 'position_anchor', 'updated_at'])
 
     return JsonResponse({'ok': True})

static/js/app.js

@@ -2788,29 +2788,10 @@ async function _saveBookMeta(books) {
   try {
     const db = await _openBookCacheDb();
     const ids = new Set(books.map(b => String(b.id)));
-    // Only load existing entries when there are books with pending offline progress
-    const pendingIds = new Set(
-      JSON.parse(localStorage.getItem(_PENDING_PROGRESS_KEY) || '[]').map(String)
-    );
-    const existing = pendingIds.size > 0 ? await new Promise(resolve => {
-      const req = db.transaction(_BOOK_META_STORE).objectStore(_BOOK_META_STORE).getAll();
-      req.onsuccess = e => resolve(Object.fromEntries((e.target.result || []).map(b => [b.id, b])));
-      req.onerror   = ()  => resolve({});
-    }) : {};
     await new Promise(resolve => {
       const tx = db.transaction(_BOOK_META_STORE, 'readwrite');
       const store = tx.objectStore(_BOOK_META_STORE);
-      for (const b of books) {
+      for (const b of books) store.put(b);
-        if (pendingIds.has(String(b.id))) {
-          const loc = existing[b.id];
-          if (loc) {
-            // Keep local progress until it has been pushed to the server
-            store.put({...b, scroll_fraction: loc.scroll_fraction, position_anchor: loc.position_anchor, last_read: loc.last_read});
-            continue;
-          }
-        }
-        store.put(b);
-      }
       store.openCursor().onsuccess = e => {
         const cursor = e.target.result;
         if (!cursor) return;
@@ -2879,8 +2860,7 @@ async function _loadAnnotationsCache(bookId, type) {
   } catch { return null; }
 }
 
-const _PENDING_SYNC_KEY     = 'diora_pending_sync';
+const _PENDING_SYNC_KEY = 'diora_pending_sync';
-const _PENDING_PROGRESS_KEY = 'diora_pending_progress';
 
 function _markPendingSync(bookId, type) {
   try {
@@ -2917,36 +2897,6 @@ async function _syncPendingAnnotations() {
   } catch {}
 }
 
-function _markPendingProgress(bookId) {
-  try {
-    const pending = new Set(JSON.parse(localStorage.getItem(_PENDING_PROGRESS_KEY) || '[]').map(String));
-    pending.add(String(bookId));
-    localStorage.setItem(_PENDING_PROGRESS_KEY, JSON.stringify([...pending]));
-  } catch {}
-}
-
-async function _syncPendingProgress() {
-  try {
-    const pending = JSON.parse(localStorage.getItem(_PENDING_PROGRESS_KEY) || '[]');
-    if (!pending.length) return;
-    const localMeta = await _loadCachedBookMeta();
-    const localById = Object.fromEntries(localMeta.map(b => [b.id, b]));
-    const remaining = [];
-    for (const bookId of pending) {
-      const loc = localById[bookId];
-      if (!loc) continue;
-      try {
-        await fetch(`/books/${bookId}/progress/`, {
-          method: 'POST',
-          headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
-          body: JSON.stringify({scroll_fraction: loc.scroll_fraction, position_anchor: loc.position_anchor || ''}),
-        });
-      } catch { remaining.push(bookId); }
-    }
-    localStorage.setItem(_PENDING_PROGRESS_KEY, JSON.stringify(remaining));
-  } catch {}
-}
-
 // Reader settings
 let readerSettings = { fontSize: 16, lineHeight: 1.8, maxWidth: 65, theme: 'dark',
                         fontFamily: 'serif', noBold: false,
@@ -3032,20 +2982,21 @@ async function loadBookList() {
         decrypted.push({id: b.id, title: `Book #${b.id}`, author: '', type: 'epub', scroll_fraction: b.scroll_fraction, position_anchor: b.position_anchor || '', uploaded_at: b.uploaded_at, last_read: b.last_read || null, keyOk: false});
       }
     }
-    // Use local progress for books that have unsaved offline changes
+    // If local cache is further ahead than the server, push it and use it for display.
-    const _pendingIds = new Set(JSON.parse(localStorage.getItem(_PENDING_PROGRESS_KEY) || '[]').map(String));
+    // Server uses max-semantics so this is always safe.
-    if (_pendingIds.size > 0) {
+    const _localMeta = await _loadCachedBookMeta();
-      const _localMeta = await _loadCachedBookMeta();
+    const _localById = Object.fromEntries(_localMeta.map(b => [b.id, b]));
-      const _localById = Object.fromEntries(_localMeta.map(b => [b.id, b]));
+    for (const b of decrypted) {
-      for (const b of decrypted) {
+      const loc = _localById[b.id];
-        if (_pendingIds.has(String(b.id))) {
+      if (loc && loc.scroll_fraction > b.scroll_fraction) {
-          const loc = _localById[b.id];
+        fetch(`/books/${b.id}/progress/`, {
-          if (loc) {
+          method: 'POST',
-            b.scroll_fraction = loc.scroll_fraction;
+          headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
-            b.position_anchor = loc.position_anchor;
+          body: JSON.stringify({scroll_fraction: loc.scroll_fraction, position_anchor: loc.position_anchor || ''}),
-            b.last_read       = loc.last_read;
+        }).catch(() => {});
-          }
+        b.scroll_fraction = loc.scroll_fraction;
-        }
+        b.position_anchor = loc.position_anchor;
+        b.last_read       = loc.last_read;
       }
     }
 
@@ -3761,7 +3712,7 @@ async function deleteBook(bookId) {
   } catch (e) {}
 }
 
-async function saveReaderProgress() {
+async function saveReaderProgress(force = false) {
   if (!currentBookId) return;
   const contentEl = $('reader-content');
   if (!contentEl) return;
@@ -3780,24 +3731,25 @@ async function saveReaderProgress() {
     _currentPositionAnchor = anchor;
   }
 
-  // Always update local cache so offline re-opens land at the right position
   _updateCachedBookProgress(currentBookId, fraction, anchor);
 
-  // Cache for sendBeacon on unload
+  const body = JSON.stringify({scroll_fraction: fraction, position_anchor: anchor, ...(force && {force: true})});
-  _lastProgressBeacon = {
+  _lastProgressBeacon = {url: `/books/${currentBookId}/progress/`, body};
-    url: `/books/${currentBookId}/progress/`,
-    body: JSON.stringify({scroll_fraction: fraction, position_anchor: anchor}),
-  };
 
   try {
     await fetch(`/books/${currentBookId}/progress/`, {
       method: 'POST',
       headers: {'Content-Type': 'application/json', 'X-CSRFToken': getCsrfToken()},
-      body: _lastProgressBeacon.body,
+      body,
     });
-  } catch (e) {
+    if (force) {
-    if (!navigator.onLine) _markPendingProgress(currentBookId);
+      const toast = document.createElement('div');
-  }
+      toast.className = 'reader-toast';
+      toast.textContent = 'Position gesetzt';
+      document.body.appendChild(toast);
+      setTimeout(() => toast.remove(), 1800);
+    }
+  } catch (e) {}
 }
 
 function closeReader() {
@@ -5202,8 +5154,7 @@ function openRadioSidebar() {
   window.addEventListener('online', async () => {
     showOfflineBanner(false);
     await _syncPendingAnnotations();
-    await _syncPendingProgress();
+    loadBookList(); // loadBookList pushes any locally-advanced progress automatically
-    loadBookList();
   });
 
   // Show banner immediately if already offline at startup

static/js/sw.js

@@ -2,7 +2,7 @@
  * diora service worker — caches the app shell for offline use.
  */
 
-const CACHE = 'diora-v13';
+const CACHE = 'diora-v14';
 const PODCAST_CACHE = 'diora-podcast-v1';
 const SHELL = [
   '/static/css/app.css',

templates/radio/player.html

@@ -338,11 +338,12 @@
         <input type="number" id="reader-progress-input" class="volume-num" min="0" max="100" value="0" style="display:none;">
         <span id="reader-progress-suffix" class="muted"></span>
       </span>
-      <button class="btn-icon" id="reader-search-btn"   onclick="toggleReaderSearch()"   title="Search">🔍</button>
+      <button class="btn-icon" id="reader-search-btn"   onclick="toggleReaderSearch()"        title="Search">🔍</button>
-      <button class="btn-icon" id="reader-settings-btn" onclick="toggleSettingsPanel()"  title="Font &amp; layout">⚙</button>
+      <button class="btn-icon" id="reader-settings-btn" onclick="toggleSettingsPanel()"        title="Font &amp; layout">⚙</button>
-      <button class="btn-icon" id="reader-bookmark-btn" onclick="addBookmark()"          title="Bookmark">★</button>
+      <button class="btn-icon" id="reader-bookmark-btn" onclick="addBookmark()"               title="Bookmark">★</button>
-      <button class="btn-icon" id="reader-bm-list-btn"  onclick="openBookmarksSidebar()" title="Bookmarks">☰</button>
+      <button class="btn-icon" id="reader-bm-list-btn"  onclick="openBookmarksSidebar()"      title="Bookmarks">☰</button>
-      <button class="btn-icon" id="reader-toc-btn"      onclick="openTocSidebar()"       title="Table of contents">≡</button>
+      <button class="btn-icon" id="reader-toc-btn"      onclick="openTocSidebar()"            title="Table of contents">≡</button>
+      <button class="btn-icon" id="reader-reset-pos-btn" onclick="saveReaderProgress(true)"   title="Diese Position als Lesefortschritt setzen (überschreibt gespeicherten Fortschritt)">⚑</button>
       <button class="btn-icon" onclick="closeReader()"  title="Close (Esc)">✕</button>
     </div>
   </div>