Subject: Fwd: Atom link relations request [IANA #189665]

From: "Lisa Dusseault" <[email-masked]>
Date: Wed, 24 Sep 2008 16:11:17 -0700

FYI on registration request received by IANA:

Attribute Value: up

Description: A URI that refers to a parent document in a hierarchy of
documents.

Expected display characteristics: Undefined; this relation can be used for
background processing or to provide extended functionality without
displaying its value.

Security considerations: Automated agents should take care when this
relation crosses administrative domains (e.g., the URI has a different
authority than the current document). Such agents should also take care to
detect circular references.

Original Request:

Contact Name :
Noah Slater

Contact Email :
[email-masked]

Type of Assignment :
An addition to the Atom Link Relations assignment.

Registry :
Atom Link Relations

http://www.iana.org/assignments/link-relations.html

Description :
The Atom Link Relations assignment has provisions for linking within series
of Atom documents but I also wish to express linking within a hierarchical
collection of Atom documents.

To do this, I would like to add an "up" relation to the assignment.

Additional Info :
The "up" relation is already used by a significant number of HTML authors
and this precedent is codified in the current HTML5 work. See section
5.11.3.18.2.:

http://www.whatwg.org/specs/web-apps/current-work/#link-type16

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From: "Peter Keane" <[email-masked]>
Date: Sat, 27 Sep 2008 17:48:49 -0500

Wouldn't such an "up"  link relation beg the question of a link
relation to express a nested  feed (a al Google's "feedLink" extension
-- http://code.google.com/apis/gdata/elements.html#gdFeedLink?).  Such
a relation expressing a nested feed would be quite useful (a topic
which has been explored here a number of times before).

--peter keane

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From: "James Holderness" <[email-masked]>
Date: Sun, 28 Sep 2008 11:49:57 +0100

> which has been explored here a number of times before).

Linking to a feed can be achieved perfectly well using the existing link 
element (see RFC 4685 for an example).

What Google's feedLink extension provides, that isn't currently achievable 
with a standard atom:link element, is the ability to embed the linked 
resource itself inside the entry. Such functionality has many much more 
applications than just embedding related feeds though. Why not embed a 
related image, or a related html page?

Either way, whether you want to link to a related feed or you want to embed 
a related feed, the feedLink extension seems to me a pretty lousy way to go 
about it.

Regards
James

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From: "Peter Keane" <[email-masked]>
Date: Sun, 28 Sep 2008 15:01:33 -0500

> element (see RFC 4685 for an example).

RFC 4685 includes the "replies" link relation, which is a more
specific example of what I was getting at.  While the Threading
Extension seems to be quite useful, it *is* quite specific, and I have
wondered if a more generic mechanism might be useful as well.
Honestly, as much as being about the need for a new "rel" value, it
gets back to the issue of being able to add metadata to a link element
-- RFC 4685 offers the thr:count attribute (analogous to the Google
feedLink 'itemCount' attribute) -- one of the very useful aspects of
the extension.  My own interest is aimed more at embedding metadata
about the nested resource than embedding the resource itself.

thanks-
peter keane

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From: James M Snell <[email-masked]>
Date: Mon, 29 Sep 2008 15:49:39 -0700

RFC4685 can be made to work for generic child relationships but it is 
rather awkward and the semantics don't fit well.  I have often felt that 
a set of "up", "down" link relations would be helpful for a variety of 
use cases and would definitely welcome any effort to define such.

- James