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

[Eugene Eric Kim]

To further clarify, supporting multiple XRD elements isn't useful for
URI-based identities, because there's only a single segment (the
entire URI) being resolved.  In an XRI, there are multiple segments.
For example, with:

  @blueoxen*eekim

there are three segments: "@", "blueoxen", and "eekim".  An XRI
authority may be able to resolve all three segments at once, in which
case it would return an XRDS document with three XRD elements.

So, XRDS does give you slightly more overhead than URI-based
identitifiers require.  However, the cost is minor, and the gain is
great.  For example, when the public i-brokers support the new XRDS
schema, then adding a bit of XRI resolution code to YADIS libraries
will be very easy.  That will give you transparent support for any
URI- and XRI-based identities that support YADIS.

-Eugene

On Sat, Feb 11, 2006 at 10:04:37AM -0800, Eugene Eric Kim wrote:

> > If there is only one XRD, why do we have this XML document rather  
> > then just some <link rel ...> tags for initial discovery?
> 
> An XRD can have multiple Service elements.  This is how multiple
> authentication protocols (and beyond) can be specified for a single
> identifier.
> 
> -Eugene

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Eugene Eric Kim ......................... http://public.xdi.org/=eekim
Blue Oxen Associates ........................ http://www.blueoxen.com/
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