Thoughts on @href/@resource completing hanging @rels

Hi all,

I've been thinking about this quite actively for the past week or two
and have since come to the same conclusion that Mark has... in short, by
simply stating that @about completes hanging rels, but @resource
doesn't, we're making RDFa more complicated. I am arguing against that
added complexity because it doesn't really get us anything, IMHO.

My position currently, which has changed from what it was 3 weeks ago,
is that @href and @resource should complete hanging @rels.

The rest of this e-mail is loose reasoning and formalization.

------------------------- Loose Reasoning ---------------------------

My first concern was that by allowing @href-@rel-@href or
@resource-@rel-@resource constructs we would confuse current XHTML
authors. It certainly was confusing to me at first, but only because
this construct was a new way of thinking about the structure of an XHTML
document (to me, at least). Mark said a few things last week that
resonated, namely - that getting people to understand this approach is a
matter of education.

Spurious triples were another concern, but after considering a couple of
samples (based only on a sample of 20-30 websites - not many, I know), I
didn't see any that had a @href-@rel-@href approach. @resource doesn't
exist and neither does @about, so the ones that we really have to worry
about are @href-@rel-@src and @href-@rel-@href constructs. I was unable
to find any web pages that had the @href-@rel-@href construct. So, I
don't think that there would be an issue with spurious triples in legacy
pages.

As for spurious triples in newly created XHTML+RDFa pages, well, there
is no such thing. Either you are authoring an XHTML+RDFa page, or you
are not. If you are authoring an XHTML+RDFa page - you should know the
basic rules (which can be explained quite simply). Let us not forget
that there are very complex rules for authoring cross-browser
Javascript/XHTML and CSS. I wouldn't put the hanging @rel issue anywhere
in the same ballpark as issues that current web designers must go
through. In other words - if this is the most complicated thing to learn
about RDFa, then that's good news.

-------------------------- Formalization ----------------------------

Just to clarify further, this is my current position using Test Cases to
illustrate:

@about subject, no hanging @rels, @href completes triples.
-----------------------------------------------------------------
<div about="#me">
   <span rel="foaf:knows" href="#ivan">
   <span rel="foaf:knows" href="#shane">
</div>
--------
<#me> foaf:knows <#ivan> .
<#me> foaf:knows <#shane> .
-----------------------------------------------------------------

@about subject, hanging @rel, @href/@resource completes triples
-----------------------------------------------------------------
<div about="#me" rel="foaf:knows">
   <span href="#ivan">
   <span resource="#shane">
</div>
--------
<#me> foaf:knows <#ivan> .
<#me> foaf:knows <#shane> .
-----------------------------------------------------------------

@href subject, hanging @rel, @href/@resource completes triples
-----------------------------------------------------------------
<div href="#me" rel="foaf:knows">
   <span href="#ivan">
   <span resource="#shane">
</div>
--------
<#me> foaf:knows <#ivan> .
<#me> foaf:knows <#shane> .
-----------------------------------------------------------------

@resource subject, hanging @rel, @href/@resource completes triples
-----------------------------------------------------------------
<div resource="#me" rel="foaf:knows">
   <span href="#ivan">
   <span resource="#shane">
</div>
--------
<#me> foaf:knows <#ivan> .
<#me> foaf:knows <#shane> .
-----------------------------------------------------------------

-- manu

-- 
Manu Sporny
President/CEO - Digital Bazaar, Inc.
blog: Intro to the Semantic Web in 6 minutes (video)
http://blog.digitalbazaar.com/2007/12/26/semantic-web-intro

Received on Monday, 21 January 2008 19:19:22 UTC