Portal access to local files.

[Alec Leamas]

Dear list,

More interesting problems (sorry, challenges :) )

We have an application (still OpenCPN, www.opencpn.org) which in some
plugins have local data like HTML files and LibreOffice documents which
should be displayed for user.

For the sake of discussion, one example is the Help.html file which
needs to be presented using Firefox. In the non-flatpak case, using
xdg-open does the trick. Inside the sandbox, we can start for example
Firefox but it don't have access to the Help.html  file inside the sandbox.

Publishing these files on some URL is not really an option, OpenCPN is a
navigation program designed to work off-line.

Is there some way to make the data accessible to the host? Other
alternatives?

Thoughts?

--alec