Seahub shared link previews for Collabora Online do not work

[jvdsn]

When creating a share link for document files, you can select the "Preview only" or "Preview and download" permissions. Unfortunately, this preview does not actually work if Collabora Online integration is used. Instead, it gives this error message: https://github.com/haiwen/seahub/blob/master/seahub/views/file.py#L1229

The reason for this is the get_wopi_dict method returning None (https://github.com/haiwen/seahub/blob/master/seahub/wopi/utils.py#L131). This method returns None because no action named view matching the file type is found in the WOPI discovery.xml.

The Collabora Online discovery.xml can be found here: https://github.com/LibreOffice/online/blob/master/discovery.xml. As you can see, for example for an ods file (our main use-case), only the edit action is specified: https://github.com/LibreOffice/online/blob/master/discovery.xml#L29. However, Collabora Online does in fact also support the view action (read-only). I assume the developers created the implicit relationship that, if a file type supports the edit action, it also supports the view action. Consequently, they did not explicitly specify the view action for a lot of file types.

As a solution, we created our own discovery.xml in /etc/loolwsd/ and duplicated every edit action for a file type with a view action. Unfortunately, this is far from perfect. It might be better if seahub also implicitly supports previews for any file if edit is supported (with Collabora Online integration). Of course, care should be taken to test every file type and ensure that read-only mode actually works.

We run Seafile Server Version: 7.1.4.

[pronichev]

I have the same Issue in OnlyOffice. My pull request not merged #4558 yet. May be your issue can be similarly fixed.

[jvdsn]

@pronichev thanks for your comment. It doesn't seem to be the exact same issue. As you can read in our post we already fixed our problem.