dbus-switchboard currently only handles files with file extensions.

The simple solution here is to download files and add extensions, then use the file manager to open the files with dbus-switchboard.

The more complex, but far better, solution is to figure out how to pass the detected mime type to dbus-switchboard and use that to determine the handler, rather than the file extension.

Does anyone know how to pass the mime type to dbus-switchboard?