W3C home > Mailing lists > Public > public-vocabs@w3.org > March 2014

Re: schema.org Roles design

From: Aaron Bradley <aaranged@gmail.com>
Date: Wed, 26 Mar 2014 14:55:12 -0700
Message-ID: <CAMbipBuE5JVSV0vnyuiV0UB9DW+ptHAMa16h+VjKH9LFV-07_w@mail.gmail.com>
To: Dan Brickley <danbri@google.com>
Cc: Jarno van Driel <jarno@quantumspork.nl>, Jason Douglas <jasondouglas@google.com>, Guha <guha@google.com>, Gregg Kellogg <gregg@greggkellogg.net>, W3C Web Schemas Task Force <public-vocabs@w3.org>
I'm baffled by @id as well.  Forget the RDFa/microdata/JSON-LD syntax
differences for a moment, I've read the proposal but still don't know from
whence the the @id values arise.

In the PDF where does...
@id "role321" come from? (e.g.1)
@id "movierole_678" come from? (e.g. 2)
@id "edurole25151" come from? (e.g. 3)

Are these arbitrarily assigned by the coder?  Are these serial?  And are
they resolvable to an IRI?

And are they integral to the Role/hasRole proposal - that is, does
everything break if they're not employed?  Am I correct in reading @ID in
e.g. 1 ("role321") is the necessary entity referred to in order to have the
"athlete property applied to the Role, instead of to a Team"?

Now returning to the syntax, I'd certainly I'd love to see any one of these
marked up with microdata. :)

> it is important to find the right
> balance between ease of adoption for publishers, expressivity, ease of
> processing etc.

I appreciate the perseverance of list members.  While my technical
expertise is limited I'm no slouch either, and Jarno ain't a slouch at all
- so if @id/@id-like functionality is crucial here it does have
implications for the "ease of adoption for publishers".



On Wed, Mar 26, 2014 at 2:22 PM, Dan Brickley <danbri@google.com> wrote:

> On 26 March 2014 20:59, Jarno van Driel <jarno@quantumspork.nl> wrote:
> > Well if @id has the same role as 'itemref' then could there also please
> be
> > some info explaining how that works, because to be honest, I sort of
> > understand the proposal but am confused about @id/itemid. e.g. to me it
> > seems @id functions the same way as @resource does in RDFa, or at least
> > that's how I read it.
>
> The following are all similar in RDF-based languages - they identify
> the entities being described:
>
> RDF/XML: about= (for subjects, i.e. the thing that has the property),
> resource= (for objects, i.e. a thing that is a value of some property)
> RDFa 1.0: about= (for subjects), resource= (for objects),
> http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014/#rdfa-attributes
> RDFa 1.1: about= (for subjects), resource= (for objects),
> http://www.w3.org/TR/rdfa-syntax/#A-about
> http://www.w3.org/TR/rdfa-syntax/#A-resource
> RDFa 1.1 Lite ... doesn't make this distinction; resource= works for
> either . http://www.w3.org/TR/rdfa-lite/#resource
> JSON-LD: @id http://www.w3.org/TR/json-ld/#node-identifiers
> Microdata: itemid=
>
> http://www.whatwg.org/specs/web-apps/current-work/multipage/microdata.html#global-identifiers-for-items
>
> Most of these also have a way of using less-than-global local
> identifiers too, as a way of joining up a graph structure from
> different trees of markup. Microdata's itemref can also sometimes be
> used for that purpose but as already discussed it is a different kind
> of mechanism.
>
> > Wouldn't the Person linking back to the AmericanFootballRole create an
> infinite loop?
>
> This is no more problematic than someone being their mother's son.
> These languages are all oriented towards describing relationships; it
> is natural that sometimes there will be loops.
>
> Dan
>
>
Received on Wednesday, 26 March 2014 21:55:40 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:29:38 UTC