Re: RDFa and Microformats

Hi Mark,

Mark Birbeck wrote:
> Hi Martin,
>
> Before I give my detailed replies, I should just say that I absolutely
> agree with your sentiment -- RDFa should be easier, and when it is, it
> will help even more people than it is now.
>
> But I think you are missing a crucial point, which is that we didn't
> arrive at a situation where RDFa is better than Microformats by
> accident, 
Sigh! Mark Let us agree that RDFa is Not better than Microformats they 
are just different approaches to the web Microformats are more about a 
"take away web" for the user say for example a iCal .ics file that they 
can export to a calendar, or a vCard .vcf, even a podcast or a m3u. its 
secondary that they also produce RDF triples, Microformats are about 
what you can see (your visitors) not what you cant. We are only seeing a 
situation where RDFa GRDDL and Microformats are beginning to converge, 
this is wholly because of RDFa because as a publisher If I chose to mark 
up my Web pages, In RDFa and Microformats, one for the RDF and one 
because I would like my users to subscribe to also subscribe to a 
webcal, we are going to end up with a  mess when you put all that 
through GRDDL.

> and now that we are in a position to build on the solid
> foundation and provide some convenient shorthands, we need to plan
> those carefully.
>
>
>   
>> "Squatting"  I dont know what you mean?
>>     
>
> You could also call it 'overloading', in the sense that you are using
> something and changing its meaning at the same time.
>
> However, I prefer 'squatting', because it conveys the idea that the
> use of the attribute for another purpose than its original intent only
> helps the squatter.
>
>   
If you had used "overloading" I would have known what you mean ;-)
>   
>> ... and "hacks", yes I liked to do that
>> back in the 90's I think people now days call that Development ;-)
>>     
>
> If "hacks" was a sustainable long-term development technique, we
> wouldn't need well thought out solutions like RDFa.
>   
What I am proposing JUST using @content from RDFa, I am not even abusing 
its semantics

@content

"a string, for supplying machine-readable content for a literal (a 
'plain literal object', in RDF terminology);"

http://www.w3.org/TR/rdfa-syntax/#rdfa-attributes

....
> But the reality is that we're in exactly the *opposite* situation with
> Microformats; due to its weaknesses, and in particular the problems
> caused by using <abbr>, you are now proposing to use a new hack.
>
> My question is, at what point do we just agree that we're going to do
> this properly, and stop going from one hack to another?
>   
....

using @title for machine data in Microformats "Is" an abuse of <abbr> 
however, so what exactly is a "hack"

>
>   
>> Why is that re-creating the same problems, its just moving  data attributes
>> to a machine readable area...
>>     
>
> The Microformats community placed machine-readable data into the
> @title attribute of <abbr>, and that caused problems for
> accessibility. Now, if you place data into @property and @content, and
> process those values outside of the normal RDFa parsing rules, you
> will cause problems for RDFa parsing.
>   
no Just @content now.

Mark, one Serious Issue I have with RDFa, and this didn't happen over 
night, it just slowly dawned on me,  In  the Creation of RDFa  this 
community has  Ignored the here and now,  what works today not maybe 
someday, You all seem to have a grand design of how RDF should be 
expressed in XHTML which is "novel"  but bares no relevance on how its 
currently done,  Instead of Acknowledging  it and  saying Great stuff, 
you say "no thats wrong" forget that this is how we do it now!
> By all means try to fix Microformats -- that's none of my business.
> But don't try to do so by messing up the generic RDFa parsing
> algorithm.
>
>
>   
I am not "messing" with the RDFa parsing model at all its easy enough to 
put @content out of triple generation if you stop and think about what 
you are saying.
>>> If you want to use @property and @content then by all means do so, but
>>> use them as defined in RDFa. In your example that would mean adding
>>> @typeof.
>>>
>>>       
>> There is really no need to, the @type of is the same as @class="vevent"
>>     
>
> There really *is* a need...because @class is not part of RDFa (at
> least not in the current version).
>
> So in your example, you want the triples generated to include these two triples:
>
>   _:a event:dtstart "2008-06-28T21:00:00" .
>   _:a event:dtend "2008-06-28T21:30:00" .
>
> I.e., you want @class="vevent" to create a new 'object', and then you
> want all subsequent properties to be tied to that.
>
> But an RDFa parser will 'see' the @property and @content values, and
> tie them to the URL of the main document:
>
>   <> event:dtstart "2008-06-28T21:00:00" .
>   <> event:dtend "2008-06-28T21:30:00" .
>
> How is the RDFa parser supposed to know that your use of @property and
> @content is 'non-RDFa', and so should be ignored?
>
>
>   
>>> Otherwise, what you are effectively proposing to do amounts to
>>> accepting that Microformats has run up against limitations,
>>>       
>> No not really I am saying HTML has Limitations that RDFa does not.
>>     
>
> RDFa was intended to solve the limitations.
>   
It doesn't though I disagree. because RDFa clashes with Microformats, 
its just added to the "tag soup" which is emerging as the Semanic web,  
what happened to "KISS"
> It's interesting that I started work on RDFa at about the same time
> that the Microformats community began. At any time in the last 5 years
> the Microformats community could have proposed the addition of new
> attributes to play the role of @property and @content, and so solve
> the <abbr> problem -- but they haven't.
>   
We Are now, sorry that the Microformats community has took its time ;-)
> I can't help thinking of the story of the little red hen.
>   

or having your cake and eating it :-)
> :)
>
>
>   
>>> but then
>>> imagining that it is ok to then pick and choose parts of a more
>>> generic solution to try to get around the problems.
>>>
>>> It's a little ironic, given that we specifically went out of our way
>>> to ensure that RDFa didn't conflict with Microformats.
>>>
>>>       
>> It does When you are asking the users of RDFa to mark up vevents like:
>>
>> <div typeof="event:Vevent">
>>  <h3 property="event:summary">Have I Got Old News For You</h3>
>>  <p property="event:location">BBC2</p>
>>  <p><span property="event:dtstart" content="2008-06-28T21:00:00">Saturday 28
>> June,
>>    9</span>-<span property="event:dtend"
>> content="2008-06-28T21:30:00">9.30pm</p>
>>  <p property="event:description">Team captains Paul Merton and Ian Hislop
>>    are joined by returning guest host Jeremy Clarkson and
>>    panellists Danny Baker and Germaine Greer for the
>>    topical news quiz. <abbr title="in stereo">[S]</abbr></p>
>> </div>
>>
>> http://rdfa.info/wiki/Tutorials#vEvent
>>     
>
> That's how it is for now -- true.
>
> But we put a lot of work into getting the fundamentals right, and now
> it will be very easy to provide ways to 'default' namespaces.
>
> Co-opting attributes without any plan, on other hand, will simply
> undermine the fundamentals.
>
>
>   
>> Its just seems counter productive to me? It seems RDFa can help the wider
>> community by suggesting....
>>     
>
> Our primary goal is to help the wider community. :)
>
> We'll do that...but we'll do it right.
>
>
>   
>> <div class="vevent">
>>  <h3 class="summary">Have I Got Old News For You</h3>
>>  <p class="location">BBC2</p>
>>  <p><span property="dtstart" content="2008-06-28T21:00:00">Saturday 28 June,
>>    9</span>-<span property="dtend" content="2008-06-28T21:30:00">9.30pm</p>
>>  <p class="description">Team captains Paul Merton and Ian Hislop
>>    are joined by returning guest host Jeremy Clarkson and
>>    panellists Danny Baker and Germaine Greer for the
>>    topical news quiz. <abbr title="in stereo">[S]</abbr></p>
>> </div>
>>
>> ...is an example, This way you help the BBC, you help the Microformats
>> Community, and you help RDFa by making it possible for authors with only a
>> basic understanding of html can get to grips with RDFa.
>>     
>
> As I said, we will provide ways to make writing RDFa easier.
>
> But not the way you are proposing.
>
>
>   
>> Why does It have to be All or nothing? RDFa (so I am now lead to believe) is
>> JUST about RDF isn't it? how a publisher extracts that information Is up to
>> him?
>>     
>
> You seem to be missing the key point, which is that Microformats has
> reached an impasse because it does not have a generic parsing
> algorithm. One of its strengths was that it provided small and easily
> learnable formats that authors could quickly add to their documents.
> But one of its weaknesses was that each of those formats could
> conflict with the others.
>
> Many people knew that this was going to be a big problem all along, so
> we began with the most difficult problem first, and that is why RDFa
> allows any format to be mixed with any other format.
>
> Now, as you rightly say, we need to add the shorthands to make things
> easier, but I can assure you that is a lot easier than creating a
> generic syntax. :)
>
> So it's not "all or nothing"; it's just that we will add the support
> for shorthands with the same care that we created the entire RDFa
> architecture.
>
> Regards,
>
> Mark
>   

More to come

Best Wishes

Martin McEvoy

Received on Monday, 15 September 2008 11:50:26 UTC