From 5fb08d8831c26bc7d04fa67f7b9cbeba99a9d4ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Leon=20B=C3=B6sche?= <leonboesche1999@gmail.com>
Date: Mon, 12 Jan 2026 16:51:16 +0100
Subject: [PATCH] Improve Collabora proxy: add load event listener and relax
 iframe sandbox for form submission

- Use window load event to ensure form element exists before submission
- Add allow-popups-to-escape-sandbox for cross-origin form POSTs
- Add allow-presentation for better compatibility
- Improved error logging for debugging form submission issues
---
 b0esche_cloud/lib/pages/document_viewer.dart |  4 +--
 go_cloud/internal/http/wopi_handlers.go      | 28 ++++++++++++--------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/b0esche_cloud/lib/pages/document_viewer.dart b/b0esche_cloud/lib/pages/document_viewer.dart
index b879d87..0d5ee79 100644
--- a/b0esche_cloud/lib/pages/document_viewer.dart
+++ b/b0esche_cloud/lib/pages/document_viewer.dart
@@ -480,11 +480,11 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
         ..src = proxyUrl
         ..setAttribute(
           'allow',
-          'microphone; camera; usb; autoplay; clipboard-read; clipboard-write',
+          'microphone; camera; usb; autoplay; clipboard-read; clipboard-write; fullscreen',
         )
         ..setAttribute(
           'sandbox',
-          'allow-same-origin allow-scripts allow-popups allow-forms',
+          'allow-same-origin allow-scripts allow-popups allow-popups-to-escape-sandbox allow-forms allow-presentation',
         );
 
       final container = html.DivElement()
diff --git a/go_cloud/internal/http/wopi_handlers.go b/go_cloud/internal/http/wopi_handlers.go
index 92ad87c..77699a3 100644
--- a/go_cloud/internal/http/wopi_handlers.go
+++ b/go_cloud/internal/http/wopi_handlers.go
@@ -683,18 +683,24 @@ func collaboraProxyHandler(w http.ResponseWriter, r *http.Request, db *database.
   <form method="POST" action="%s/loleaflet/dist/loleaflet.html" target="collabora-frame" id="collaboraForm" style="display: none;">
     <input type="hidden" name="WOPISrc" value="%s">
   </form>
-  <iframe name="collabora-frame" id="collabora-frame" style="width:100%%; height:100%%; border:none; position:absolute; top:0; left:0;"></iframe>
+  <iframe name="collabora-frame" id="collabora-frame" style="width:100%%; height:100%%; border:none; position:fixed; top:0; left:0;"></iframe>
   <script>
-    (function() {
-      var form = document.getElementById('collaboraForm');
-      var frame = document.getElementById('collabora-frame');
-      if (form && frame) {
-        console.log('[COLLABORA] Submitting form to Collabora...');
-        form.submit();
-      } else {
-        console.error('[COLLABORA] Form or frame element not found!');
-      }
-    })();
+    window.addEventListener('load', function() {
+      setTimeout(function() {
+        var form = document.getElementById('collaboraForm');
+        if (form) {
+          console.log('[COLLABORA] Form found, submitting...');
+          try {
+            form.submit();
+            console.log('[COLLABORA] Form submitted successfully');
+          } catch(e) {
+            console.error('[COLLABORA] Form submission failed:', e);
+          }
+        } else {
+          console.error('[COLLABORA] Form element not found!');
+        }
+      }, 100);
+    });
   </script>
 </body>
 </html>`, collaboraURL, wopiSrc)