Fix: Create form in parent document to POST to Collabora iframe

- Data URL iframe form submission was blocked by CORS
- New approach: create iframe in viewport, form in document body
- Form targets iframe by name, submits WOPISrc to loleaflet.html via POST
- Form submission happens in parent document context, not sandboxed iframe
- This avoids CORS issues and ensures form actually submits
This commit is contained in:
Leon Bösche
2026-01-12 15:53:05 +01:00
parent 64690231c2
commit 2fa5f0441a

View File

@@ -449,14 +449,18 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
}
Widget _buildCollaboraIframe(String wopisrc) {
// For Collabora Online, we need to POST the WOPISrc, not GET it
// Create an HTML page with auto-submitting form and set as iframe src
// For Collabora Online, POST the WOPISrc to loleaflet.html
// We'll create an iframe and submit a form to it from the page level
final String viewType =
'collabora-form-${DateTime.now().millisecondsSinceEpoch}';
'collabora-viewer-${DateTime.now().millisecondsSinceEpoch}';
ui.platformViewRegistry.registerViewFactory(viewType, (int viewId) {
// Create the iframe
// Create a unique iframe name
final iframeName = 'collabora-$viewId';
// Create the iframe that will receive the form submission
final iframe = html.IFrameElement()
..name = iframeName
..style.border = 'none'
..style.width = '100%'
..style.height = '100%'
@@ -468,34 +472,10 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
)
..setAttribute(
'sandbox',
'allow-same-origin allow-scripts allow-popups allow-forms',
'allow-same-origin allow-scripts allow-popups allow-forms allow-pointer-lock allow-presentation allow-modals allow-downloads',
);
// Create an HTML page with an auto-submitting form
final htmlContent =
'''
<!DOCTYPE html>
<html>
<head>
<title>Loading...</title>
</head>
<body style="margin: 0; padding: 0;">
<form method="POST" action="https://of.b0esche.cloud/loleaflet/dist/loleaflet.html" style="display: none;">
<input type="hidden" name="WOPISrc" value="$wopisrc">
</form>
<script>
document.forms[0].submit();
</script>
</body>
</html>
''';
// Set iframe src to a data URL with the form
final dataUrl =
'data:text/html;charset=utf-8,${Uri.encodeComponent(htmlContent)}';
iframe.src = dataUrl;
// Create a container
// Create container
final container = html.DivElement()
..style.width = '100%'
..style.height = '100%'
@@ -504,6 +484,46 @@ class _DocumentViewerModalState extends State<DocumentViewerModal> {
..style.overflow = 'hidden'
..append(iframe);
// Create form in the parent document that targets this iframe
// We need to do this after the view is registered but before it's displayed
// So we use a setTimeout to ensure the DOM is ready
Future.delayed(Duration.zero, () {
// Get or create a hidden form container in the document body
final formContainer = html.document.querySelector('#collabora-forms') ??
(html.DivElement()
..id = 'collabora-forms'
..style.display = 'none'
..style.position = 'absolute'
..style.width = '0'
..style.height = '0'
..style.overflow = 'hidden');
if (html.document.querySelector('#collabora-forms') == null) {
html.document.body!.append(formContainer);
}
// Create the form
final form = html.FormElement()
..id = 'form-$iframeName'
..method = 'POST'
..action = 'https://of.b0esche.cloud/loleaflet/dist/loleaflet.html'
..target = iframeName;
// Add WOPISrc input
final input = html.InputElement()
..type = 'hidden'
..name = 'WOPISrc'
..value = wopisrc;
form.append(input);
formContainer.append(form);
// Submit the form after a short delay to ensure everything is connected
Future.delayed(Duration(milliseconds: 100), () {
form.submit();
});
});
return container;
});