Re: [httpapi] linkset: use of "absolute URIs", corner cases, formatting

Christian Amsüss <christian@amsuess.com> Tue, 15 June 2021 08:17 UTC

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Date: Tue, 15 Jun 2021 10:17:18 +0200
From: Christian Amsüss <christian@amsuess.com>
To: Erik Wilde <erik.wilde@dret.net>
Cc: draft-ietf-httpapi-linkset@ietf.org, httpapi@ietf.org
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Subject: Re: [httpapi] linkset: use of "absolute URIs", corner cases, formatting
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Hi,

> > Multi-rel links
> > ---------------
> > [...] -- but then, which of these do the target attribtues get attached
> > to? The first? All?
>
> RFC 8288 makes it clear that it's simply a syntax variant to list links
> separately or use the "space-separated shortcut".
> 
> "The rel parameter can, however, contain multiple link relation types. When
> this occurs, it establishes multiple links that share the same context,
> target, and target attributes."
> 
> this implies that all of the link's data applies to all links established by
> multiple rel values. do you disagree?

Thanks, the section of 8288 is pretty explicit -- so it may just be
worth pointing out that such links can multiply in size when expressed
in linkset. (Think of what `</>;rel="a b c d e f g h i j k l m n o p
q";foo="hello multiplication factor"` would look like). Plus, a
back-converter should be advised to aggregate links that only differ in
their rel.

I don't see any much better way, though.

> it seems to me that if we list everything that is not round-tripped, we
> create a lot of noise and little information. we could add some general
> language about this in section 4.2, though. if anybody thinks that would add
> value, please raise an issue. thanks!

Maybe then it's more practical to describe what *is* round-tripped (that
is, the information can be round-tripped, but serialization details
including order can't).

> 
> > rel=linkset vs. more generic "see also"
> > ---------------------------------------
> > 
> > The to-be-defined linkset relation does, by its description,
> > characterize the target as "providing more information about" the
> > context, but does so in a very technology specific way.
> 
> it's not "more information about", it's more specifically "a set of web
> links in which the resource is participating".
> [...]
> we've discussed this and believe that being more specific about the linked
> resource providing web links makes sense. we have specific scenarios
> (section 3) which really are about links, and not just generic "other info
> about the resource" scenarios.

I fail to see the difference; in
</foo>;rel=hasMoreInfo;type=application/linkset, the type says that
thiis is a set of web links, and the hasMoreInfo strongly implies (no
less strongly thatn rel=linkset would) that the link context is
mentioned in there.

If that further discussion is on record anywhere, I'm happy to read up
to understand the difference point, but just from Section 3 I don't, and
still see rel=linkset to nail down two orthogonal aspects of a link
relation where one aspect is already covered by another target
attribute.

BR
c

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