Subject: [link-relations] Example of App Data for Link Relations

From: mike amundsen <[email-masked]>
Date: Mon, 1 Aug 2011 11:32:55 -0400

I've been working through the Web Linking RFC (5988) and am not clear
on how Link Relation Application Data[1] actually *looks* in an
implementation. I do not see any registered App Data[2] items and have
not yet found an illustration of one anywhere online. I am especially
interested in any discussion threads that lead to the creation of the
App Data registry.

Is App Data really just a registered link-extension[3]? And can this
link-extension be applied to any *existing* Link Relation Type - even
one that has not pre-defined the use of link-extensions?

As an example, given the following App Data registration:
- Application Name: foo
- Description: The foo application is used to process all baz interactions.
- Default: none.

Does the above registration result in the following possible Link Relation?

rel="related;foo=bar"
or
rel="alternate;foo=bar"
etc.

Thanks in advance for any comments, examples, pointers to content that
explains this aspect of RFC5988.

[1] http://tools.ietf.org/html/rfc5988#section-6.3
[2] http://www.iana.org/assignments/link-relations/link-relations.xml#link-relations-2
[3] http://tools.ietf.org/html/rfc5988#section-5
mca
http://amundsen.com/blog/
http://twitter.com@mamund
http://mamund.com/foaf.rdf#me

#RESTFest 2011 - Aug 18-20
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---

From: Julian Reschke <[email-masked]>
Date: Tue, 02 Aug 2011 00:17:27 +0200

> interested in any discussion threads that lead to the creation of the

The use case that was on the table was HTML5, which attaches two flags 
to each relation. It was argued that the registry must be able to store 
those, and that it must be machine-readable so that validators can 
self-update.

> Is App Data really just a registered link-extension[3]? And can this

No.

> - Description: The foo application is used to process all baz interactions.

Bad example :-)

> Does the above registration result in the following possible Link Relation?

No. Application data is not about parameters on the wire.

> ...

You may want to look at 
<http://www.ietf.org/mail-archive/web/link-relations/current/msg00000.html>. 
In the end this wasn't used as the HTML WG for now decided to go 
somewhere else.

Best regards, Julian

---

From: mike amundsen <[email-masked]>
Date: Mon, 1 Aug 2011 20:12:59 -0400

On Mon, Aug 1, 2011 at 18:17, Julian Reschke <[email-masked]> wrote:
> The use case that was on the table was HTML5, which attaches two flags to
> each relation. It was argued that the registry must be able to store those,
> and that it must be machine-readable so that validators can self-update.

Understood.

>> Is App Data really just a registered link-extension[3]? And can this

Got it.

>> - Description: The foo application is used to process all baz

Ok.

> No. Application data is not about parameters on the wire.

Aha!  first time i've seen that in print.

> In the end this wasn't used as the HTML WG for now decided to go somewhere
> else.

I'd read this thread a couple times and it didn't really "help me"
since I had missed the point that App Data is not about the wire, just
the documentation.

> Best regards, Julian

Thanks.