W3C home > Mailing lists > Public > public-lod@w3.org > March 2010

Re: RDFa for Turtles

From: Stephane Corlosquet <scorlosquet@gmail.com>
Date: Thu, 11 Mar 2010 08:53:11 -0500
Message-ID: <1452bf811003110553x1fcfb865vb4fcbec8749050c5@mail.gmail.com>
To: Paul Houle <ontology2@gmail.com>
Cc: Linked Data community <public-lod@w3.org>
>
> <meta about="{subject}" rel="{predicate}" content="{object}" />
> <link about="{subject}" rel="{predicate}" href="{object}" />
>

You might also want to add typeof="{rdf_type}", it's a nice shortcut to
assert an extra rdf:type triple about the subject. Beware however that this
will create a blank node if no about attribute is specified, so you want to
make sure you combine it with an about attribute where you explicitely state
the subject like in the examples above. Quoting toby's advice here:
"explicitly set @about on *all* the <link> and <meta> elements".

all the best,
Steph.

On Wed, Mar 10, 2010 at 12:03 PM, Paul Houle <ontology2@gmail.com> wrote:

> I'm working on linked data output for
>
> http://ny-pictures.com/
>
> so I'm trying to come up with an "RDFa Profile" that's appropriate for my
> application;  goals are (i) separation of presentation in content (I can
> move my <divs> around and never end up losing an "about") and (ii) high
> compatibility with existing web browsers and applications.
>
> Last night I was researching the WHAT-WG HTML 5 standards from metadata and
> was pretty terrified,  and came out with the conclusion that we really need
> a simple way to assert RDF triples that anybody can lose and that has little
> impact on current server and client toolchains.
>
> ---------
>
> Restriction:  All RDFa statements will be asserted in the <head> of the
> document,  using certain patterns.
>
> The patterns that will be used are
>
> <meta rel="{predicate}" content="{object}" />
> <meta rel="{predicate}" content="{object}" datatype="{type_of_object}" />
>
> when we want to assert non-link properties about the current document
>
> <link rel="{predicate}" href="{type_of_object}" />
>
> for asserting link properties.  Now,  if we want to assert a property with
> a different subject,  we can just write
>
> <meta about="{subject}" rel="{predicate}" content="{object}" />
> <link about="{subject}" rel="{predicate}" href="{object}" />
>
> There's also a nice bit of syntactic sugar
>
> <link rev="{predicate}" href="{subject}" />
>
> when we want to make an assertion about which the current document is the
> object.
>
> My understanding is that this is a correct subset of RDFa that makes it
> possible to specify arbitrary triples.  Am I missing anything?
>
> I was initially worried about the lack of the name element on the meta
> tags,  but a close look at the HTML 4 spec shows that the name is not a
> required element.  I don't believe that this syntax is going to cause any
> problems for mainstream software
>
> ------
>
> So far I've been sticking to the letter of HTML and RDFa specs,  or at
> least trying to.  Now I'm going to add
>
> Requirement: Ability to embed RDFa in a document that is not,  globally,  a
> valid XHTML document
>
> There are two major reasons for this.  (A) the ability to create the web
> experiences we want with standard markup is something that web developers
> have long suffered.  Finally,  if you get your DOCTYPEs right,  you can get
> fairly consistent rendering with five major web browsers.  If you use
> XHTML,  you get less consistent behavior from current web browsers.
>
> (B) Most conventional web toolchains (PHP,  JSP,  Cold Fusion,  Ruby on
> Rails,  etc.) produce HTML by concatenating fragments of text.  In that
> context,  it's almost impossible to verify that a dynamic web site is going
> to produce valid XHTML under all circumstances.  Now,  you can build your
> documents with real XML tools,  but that leads to a serious intermingling of
> presentation and content:  it's hard to have a designer design a template in
> Dreamweaver,  and it could require a rookie programmer hours to figure out
> how to change a simple bit of text that is output by the application.
> ASP.NET actualy does have a reasonable answer,  but it's pretty hard to
> get anything else right if you use ASP.NET
>
>
>
>
>
>
Received on Thursday, 11 March 2010 13:55:46 UTC

This archive was generated by hypermail 2.3.1 : Sunday, 31 March 2013 14:24:25 UTC