Fix: Refactor Collabora iframe setup for improved readability and maintainability

b0esche_cloud/lib/pages/document_viewer.dart

@@ -406,10 +406,11 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
         // Build Collabora Online viewer URL with WOPISrc
         // The WOPISrc must be URL-encoded and kept encoded
         // We use a double-encoding approach: encodeComponent keeps it encoded through iframe.src
-        final baseUrl = 'https://of.b0esche.cloud/loleaflet/dist/loleaflet.html';
+        final baseUrl =
-        final collaboraUrl = Uri.parse(baseUrl)
+            'https://of.b0esche.cloud/loleaflet/dist/loleaflet.html';
-            .replace(queryParameters: {'WOPISrc': wopiSession.wopisrc})
+        final collaboraUrl = Uri.parse(
-            .toString();
+          baseUrl,
+        ).replace(queryParameters: {'WOPISrc': wopiSession.wopisrc}).toString();
 
         // Use WebView to display Collabora Online
         return _buildWebView(collaboraUrl);
@@ -457,15 +458,26 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
   }
 
   Widget _buildCollaboraIframe(String collaboraUrl) {
-    // For Collabora Online, create an iframe that loads the editor directly
+    // For Collabora Online, we need to POST the WOPISrc, not GET it
-    const String viewType = 'collabora-iframe';
+    // Create an iframe and submit a form to load the document
+    const String viewType = 'collabora-form';
 
-    ui.platformViewRegistry.registerViewFactory(
+    ui.platformViewRegistry.registerViewFactory(viewType, (int viewId) {
-      viewType,
+      // Extract the WOPISrc from the URL
-      (int viewId) {
+      final uri = Uri.parse(collaboraUrl);
-        // Create the iframe with the properly encoded Collabora URL
+      final wopisrc = uri.queryParameters['WOPISrc'] ?? '';
+
+      // Create a container for the form and iframe
+      final container = html.DivElement()
+        ..style.width = '100%'
+        ..style.height = '100%'
+        ..style.margin = '0'
+        ..style.padding = '0'
+        ..style.overflow = 'hidden';
+
+      // Create the iframe first
       final iframe = html.IFrameElement()
-          ..src = collaboraUrl
+        ..name = 'collabora-iframe'
         ..style.border = 'none'
         ..style.width = '100%'
         ..style.height = '100%'
@@ -475,15 +487,36 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
           'allow',
           'microphone; camera; usb; autoplay; clipboard-read; clipboard-write',
         )
-          // Remove allow-same-origin for security, add allow-popups-to-escape-sandbox
         ..setAttribute(
           'sandbox',
           'allow-scripts allow-popups allow-forms allow-pointer-lock allow-presentation allow-modals allow-downloads allow-popups-to-escape-sandbox',
         );
 
-        return iframe;
+      container.append(iframe);
-      },
+
-    );
+      // Create a hidden form that will POST to Collabora
+      final form = html.FormElement()
+        ..method = 'POST'
+        ..action = 'https://of.b0esche.cloud/loleaflet/dist/loleaflet.html'
+        ..target = 'collabora-iframe'
+        ..style.display = 'none';
+
+      // Add WOPISrc as a hidden input
+      final wopisrcInput = html.InputElement()
+        ..type = 'hidden'
+        ..name = 'WOPISrc'
+        ..value = wopisrc;
+
+      form.append(wopisrcInput);
+      container.append(form);
+
+      // Use a timer to submit the form after the iframe is fully loaded
+      Future.delayed(const Duration(milliseconds: 100), () {
+        form.submit();
+      });
+
+      return container;
+    });
 
     return HtmlElementView(viewType: viewType);
   }