Re: Yadis Spec .9 Change Proposal: Section 7.3.1 clarify multiple XRD

If there is only one XRD, why do we have this XML document rather  
then just some <link rel ...> tags for initial discovery?

On 10-Feb-06, at 11:37 AM, Drummond Reed wrote:

> One factor that may mitigate this risk somewhat is that I see few  
> reasons in
> a YADIS context for the provider of an XRDS document to provide  
> more than
> one XRD element. The multi-XRD capability is intended for XRI client
> resolvers and proxy resolvers who need to provide the results of a
> resolution request for a delegated (multi-authority) XRI. While this
> multi-XRD capability may also have uses in other potential resource
> description or service discovery scenarios, in the typical YADIS  
> scenario
> the XRDS document will just be self-describing and thus not need to  
> contain
> more than one XRD element.
>
> =Drummond
>
> -----Original Message-----
> From: yadis-bounces@xxxxxxxxxxxxxxx [mailto:yadis- 
> bounces@xxxxxxxxxxxxxxx]
> On Behalf Of Larry Drebes
> Sent: Friday, February 10, 2006 8:47 AM
> To: yadis@xxxxxxxxxxxxxxx
> Subject: Re: Yadis Spec .9 Change Proposal: Section 7.3.1 clarify  
> multiple
> XRD
>
>
> I hope you are wrong :).   I suspect that the early use of YADIS  
> will be
> based around several common libraries and not one-off implementations.
> This flaw is very easy to test for, and if broken, it should be  
> easy to fix.
> larry-
>
> Martin Atkins wrote:
> > Unfortunately, this is one of those things that relying parties are
> > going to get wrong. I guarantee it!
> >
> > Previous experience shows that there are two kinds of "wrong" when it
> > comes to implementing specs:
> > * You got it wrong so it doesn't work at all.
> > * You got it wrong so it works most of the time except in some funny
> > corner-cases and all of the spec authors are now scowling at you.
> >
> > This is the latter. Implementors are (by and large) lazy. They'll
> > implement the bare minimum to make it look like it works. Most YADIS
> > resource descriptors are going to have only one XRD segment.
> > Implementors will probably use XPath like /XRDS/XRD/Service which  
> > will,
> > of course, match the service elements in *all* XRD segments.
> >
> > So while it's obvious the YADIS spec has to take a definite  
> > position on
> > this subject, everyone should be prepared for the fact that almost  
> > every
> > relying party implementation is going to get this wrong and consider
> > what the implications of this are.
> >
> > Cheers,
> > -Martin