Re: embed RDFa --> embed coolness into Yahoo search results

Ian Hickson wrote:
> Your original point still stands, though.

No, it doesn't, please stop spreading these exaggerated points. Bugs are
bugs, and we'll fix them. That said, there is no deep misunderstanding
of CURIEs from anywhere except theoretical examples at this point.

> Some tests that can be passed to Yahoo!'s testing page:
> 
>    http://hixie.ch/www/tests/adhoc/rdfa

Thanks for reporting these, we'll take a look.

> More worryingly, though, I have to say that in trying to write these tests 
> I had an extremely confusing experience reading the RDFa specification.

Did you read the spec or the primer? Which parts were confusing? The
questions you ask below are very easily answered by reading the Primer.

http://www.w3.org/TR/xhtml-rdfa-primer/

> When can one use href="" and when can one use resource=""?

Anywhere. @resource is meant to override @href when the clickable link
is not quite the same as the semantic link. This is useful only in some
cases, so I would agree that Yahoo could probably just use @href most of
the time. I'll mention it to them.

> Does using content="" with an absolute URL work also?

No. content is a literal. There used to be an example in the Primer of
this, but I think I must have removed them in the simpler rewrite.
That's unfortunate, and my mistake.

The idea is this:

<span property="dc:date" content="2009-03-17">today</span>

The point is to override the human-rendered when needed.

> What are the implications of using property="" instead of rel=""?

@property is for literal objects, @rel is for URI objects.

<span property="dc:title">The Title of the Book</span>

<a rel="dc:creator" href="http://ben.adida.net">The Author of the Book</a>.

This should be clear from the Primer, Section 2.2:

http://www.w3.org/TR/xhtml-rdfa-primer/#id84624

> When does nesting matter and when 
> does it not matter?

Nesting matters if you leave some "dangling triples" that can be
completed by nested statements. That's a more advanced topic, though, we
should probably make sure the above points are clear before we tackle
this one.

> Does it matter whan URL the assertions are made about, 
> or will the SearchMonkey tool simply grab all the assertions from the 
> document regardless of what URL they are about?

I think they grab everything but they link it to the appropriate URL.
Certainly it would be a bug if they merged statements about different
URLs. I'll check out your tests to see if there's one that highlights this.

> What parts are necessary 
> and what parts are optional?

Can you be more precise? In RDFa? In the SearchMonkey vocabularies?

> The more I try to learn and use RDFa, the more confused I get.

Given the questions you ask above, and given that plenty of other folks
haven't been nearly this confused (Digg, many small CC publishers,
etc...), I'm wondering where you started your reading? Maybe we need to
be clearer about which document is best to start with, and we may need
to add some more advanced cases to the Primer since they're being used
more quickly than I anticipated.

-Ben

Received on Tuesday, 17 March 2009 19:18:16 UTC