[foaf-dev] Proposal: deprecate pastProject and currentProject

Dan Brickley danbri at danbri.org
Mon Dec 14 12:43:56 CET 2009


On Mon, Dec 14, 2009 at 12:20 PM, Richard Cyganiak <richard at cyganiak.de> wrote:
> On 13 Dec 2009, at 21:12, Dan Brickley wrote:
>>
>> There's a risk with this stuff of building parallel sets of
>> properties; those that link to pages and those that link to the
>> primary topics of those pages. RDFa biases us towards the former,
>> modelling clarity towards the latters.
>
> I would almost go as far as calling the former (workplaceHomepage,
> schoolHomepage) an anti-pattern.

Strong words! Remember we're in an environment where people complain
about every little bit of perceived complexity.

> I don't think that RDFa biases us towards
> them. Adding the extra @typeof is not particularly hard, and provides an
> obvious way of attaching a foaf:name to the entity as well.

Care to draft some markup snippets?  Here is some fresh HTML markup,
autobiographical, true and handwritten using real Web sites.

1a.
<p>
My name is Dan Brickley and I spent much of the '80s at <a
href="http://www.westergate.w-sussex.sch.uk/">Westergate School</a>.
Before that I was at <a
href="http://www.eastergate.w-sussex.sch.uk/">Eastergate</a>, where we
moved in 1978 from <a
href="http://en.wikipedia.org/wiki/Hamsey_Green">Hamsey Green</a> near
<a href="http://en.wikipedia.org/wiki/Croydon">Croydon</a> where I
attended the <a href="http://hginfant.schoolwebbuilder.co.uk/">infants
school</a> I guess from late 1976 to summer 1978. Before that, it's
all a blur :)
</p>

2a. Same thing with minor RDFa FOAF
<p
about="http://danbri.org/foaf.rdf#danbri" typeof="foaf:Person"
xmlns:foaf="http://xmlns.com/foaf/0.1/">
My name is <span property="foaf:name">Dan Brickley</span> and I spent
much of the '80s at <a rel="foaf:schoolHomepage"
href="http://www.westergate.w-sussex.sch.uk/">Westergate School</a>.
Before that I was at <a rel="foaf:schoolHomepage"
href="http://www.eastergate.w-sussex.sch.uk/">Eastergate</a>, where we
moved in 1978 from <a
href="http://en.wikipedia.org/wiki/Hamsey_Green">Hamsey Green</a> near
<a href="http://en.wikipedia.org/wiki/Croydon">Croydon</a> where I
attended the <a rel="foaf:schoolHomepage"
href="http://hginfant.schoolwebbuilder.co.uk/">infants school</a> I
guess from late 1976 to summer 1978. Before that, it's all a blur :)
</p>

Using http://www.w3.org/2007/08/pyRdfa/ I get
  <foaf:Person rdf:about="http://danbri.org/foaf.rdf#danbri">
    <foaf:name>Dan Brickley</foaf:name>
    <foaf:schoolHomepage rdf:resource="http://www.eastergate.w-sussex.sch.uk/"/>
    <foaf:schoolHomepage
rdf:resource="http://hginfant.schoolwebbuilder.co.uk/"/>
    <foaf:schoolHomepage rdf:resource="http://www.westergate.w-sussex.sch.uk/"/>
  </foaf:Person>

3a. Richard's version - entity rather than page centric?

Can you post RDFa and triples here. Non-scary HTML is a goal, ie.
stuff that people can write without thinking much about RDF.

>> Reminds me of the XFN mapping
>> discussion too.
>>
>> workplaceHomepage, schoolHomepage are in former category; pastProject,
>> currentProject too on my preferred reading;
>
> I'm checking the spec and realising that currentProject indeed "relates a
> person to a document". I could have sworn that its range was foaf:Project.
> That's what I was thinking all those years anyway, and that's how I've been
> using it.

Not suprising. Generally we've had 'page' in the name of properties
that point to pages/docs. And it might be that things were changed or
clarified some years ago. It's all in the public SVN if you care to
dig.

> What's the basis for the assertion in the spec that "in practice" it's used
> to refer to pages?

In practice it's barely used, but the spec says it's for pages.

http://www.sindice.com/search?q=*+%3Chttp%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2FcurrentProject%3E+*&qt=advanced

(finds 701 occurances)

... Advogato seems the main not-by-hand publisher, and they link to
project homepages.

If there was a trivial way to always go from a page, eg.
http:/foo.example.org/ to a URI for the primary topic of that page,
life might be easier in several ways.

http://larry.masinter.net/duri.html has been around for a while, so
tdb:http://foo.example.org/ is one option. And not particularly
unsemantic since the html page can always contain RDFa.

Another idea is to find some generalisation of the
http://foo.eample.org/#concept pattern we've seen around, where we
want a symbolic name for something that is not an anchor in the HTML
sense, but is the URI for the thing the page is talking about. I have
been wondering about chars that are disallowed as HTML anchor names,
to give us a cleaner namespace with no chance of clashes. Perhaps
http://foo.example.org/#! could be a common prefix and
http://foo.example.org/#!! a convention for 'the thing described by
this document'. It doesn't seem used at the moment for anything else.

I'm a bit worried we'll end up doubling the number of links, since
whenever we mention some other document in an HTML hyperlink, we'll
have to mention the thing it is about as well. So perhaps some
conventions for hopping between the document view and the thing view
could be helpful here...

cheers,

Dan


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