Media/Device Type Spec???

Lars Hallberg spam at micropp.se
Fri Aug 20 13:04:45 EEST 2004


Dave Cridland wrote:

> My problem with that is threefold:
>
> 1) It breaks the useful ability to be able to throw a Subversion HTTP 
> URI at the webbrowser, or an innocent person.
> 2) 'dav' scheme is registered, but means something else, 'davs' is 
> not. [dav: is a URN used for XML namespacing]
> 3) Finally, it's not a generic solution - there's an increasing number 
> of protocol overloads being defined based on DAV. 'Defining' URI 
> schemes for each of them fragments the URI space, and prevents them 
> from being treated as plain DAV or HTTP, both of which being useful 
> properties, and, one would hope, the reason they're defined as being 
> HTTP/DAV overloads.


I see Your point, and it's a good one!

But ther is a need, and both KDE and Gnome are doing stuff, incompatibel 
and standard braking stuff :-(

> Some examples of protocols which are overloaded HTTP:
>
> a) DAV, obviously.
> b) DeltaV (DAV with extras)
> c) Subversion/HTTP (DeltaV with extras)
> d) XCAP (HTTP with funny URIs and, IIRC, extra ETags)
> e) *DAV (For instance, CalDAV, et al: All DAV with bells on)
>
> Obviously, this kind of protocol overloading makes little sense in 
> many cases - possibly even most cases - but it does make sense in 
> some. (Like DAV, Subversion, and, erm... Probably others.)
>
> But aside from my personal viewpoint on whether the overloads 
> themselves are sensible or not, they exist, and a better method of 
> handling them needs to be found.

What about leving URI as is and expand it to MURI, Meta URI. Something 
like this:

(class=Subversion,mime=image/jpeg) http://foo.org/bar.jpg

The meta part (in paranteses) is optional, but may cary kind of any 
extra info.

And rekomend that apps taking URI shuld at least lern to strip the meta 
information even if they dont use it. Else users is able to copy and 
past only the uri part (the space in the MURI is to make that a litle 
more obvius).

Freedesktop can maintain a standard of meta-atribute and valus (like a 
server type (or class) hierarki).

KDE kan add kde-foo atribut and Gnome Gnome-foo atribut. Apps kan ignore 
atribute they dont know. It's not interfeering with curent standards, 
it's extendable.

Might be usefull for device/media classes that ben up laitly too. 
another use I can see imediatly is a lcopy atribut specifying an uri (or 
maybe an muri) to a local copy, so a vfs that download the file before 
knowing what to do with it can pass it om to a app specifying both the 
original uri, the local copy, and identified mimetype. So that app dont 
need to redo the job (most important the download).

Make sens to leave the URI defenission to IETF, It make sens to maintain 
a standard of metadata att freedesktop.org (imho).

/LaH




More information about the xdg mailing list