.desktop file: supported URL schemes key

David Faure faure at kde.org
Fri Nov 5 09:36:44 PDT 2010

On Friday 05 November 2010, Bastien Nocera wrote:
> On Mon, 2010-10-11 at 13:08 +0200, David Faure wrote:
> > The recent discussion raises again something that has been a need for a
> > very long time.
> > 
> > Some programs support URLs (Exec=foo %u) but not all URLs.
> > For instance VLC supports http, ftp, and smb.
> > We need to know that we can pass it such URLs, and not others.
> > 
> > I would like to propose a key UrlSchemes in the desktop entry standard,
> > as a ;-separated list of supported URL schemes. For instance, for vlc:
> > UrlSchemes=http;ftp;smb;
> This problem pretty much doesn't exists in GNOME, as:
> - either a local FUSE URI will be passed to the program (eg. opening
> smb://myserver/myshare/foobar.txt will actually pass the URI version of
> "~/.gvfs/myshare on my server/foobar.txt")

1) this means you pass a FUSE URI to all programs no matter what, never the 
real URI? Otherwise, how can you find out if you should do one or the other? 
E.g. if you sometimes pass URI (to gnome programs), how do you not pass 
unsupported-URIs to KDE programs?

I think the solution you described is for the case where no %u is present. But 
how would you handle a KDE program, which comes with %u but doesn't support 
ssh:// (assuming that's a valid gnome scheme; in kde it's called fish or sftp)?
This is exactly why we need a UrlSchemes key.

2) I have strong objections against FUSE, what happens if the server goes 
offline, won't the mount hang like NFS mounts do in such a situation? But we 
probably should not get into technical discussions on a list which is supposed 
to be about common standards instead :-)

=> Let's use different fallback solutions when the URL scheme is not supported, 
if we decide to, but for this we first need to come up with a way to -know- 
that a given URL scheme is unsupported by a given application.

> This means that you would only have problems when launching GNOME apps
> under KDE [...]

... or OpenOffice, or anything else, yes.
Under KDE and under any other environment that doesn't use FUSE. Like any 
platform where FUSE is not available, for instance.

And the problem exists when launching KDE apps under GNOME, too, if I'm right 
about 1) above.

David Faure, faure at kde.org, http://www.davidfaure.fr
Sponsored by Nokia to work on KDE, incl. Konqueror (http://www.konqueror.org).

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