Re: [RDFa] ISSUE-3 @class and @role for rdf:type

Hm. Sigh...:-(


Ben Adida wrote:
> It's important to remember that we agreed that it is too late to change
> @class, since we've published many talks and documents that use it. I
> would strongly vote for not revisiting this. Having an additional
> attribute may be okay to provide an alternative for folks who find
> @class distasteful, but I'm not hugely in favor of it (one way is better
> than two.)
> -Ben
> Ivan Herman wrote:
>> Mark,
>> as I said: I am not sure about the usage of @role, I did not follow the
>> details of that. I am happy to disregard @role for now.
>> I also agree that rdf:type is important, so it is probably a good idea
>> to give a shorthand (just like Turtle does). @isA sounds perfectly fine
>> to me...
>> Ivan
>> Mark Birbeck wrote:
>>> Hi Ivan,
>>> I also prefer a new attribute.
>>> The only thing I feel really strongly about is that we don't use @role
>>> for rdf:type, since I think that will come back to bite us in the
>>> future. So for me, that leaves two choices, use @class or use a new
>>> attribute.
>>> I can live with using @class, but I do agree that it comes with some
>>> baggage. I don't mean that from the point of view of some kind of
>>> 'backlash', since I think people are using @class semantically already
>>> (even without using microformats). What I mean is that I can easily
>>> imagine people forgetting to put foaf:Person (for example) in the
>>> class attribute on the containing element, since novice authors would
>>> probably see it as 'I must set the CSS class to foaf:Person for this
>>> to work'.
>>> I also believe that rdf:type is so important that it should be part of
>>> the core RDFa attributes, that are independent of any host language. A
>>> host language may have an additional way of doing this, and we might
>>> even decide in the future to use @class in HTML after all. But by
>>> having our own attribute, it means that there is a core way of marking
>>> up rdf:type that is always there, no matter what language is the host.
>>> So to summarise; my preferred approach would be to leave @class
>>> undefined for now--we can always come back to this in a future
>>> version--and use @isA or something like that, to indicate the rdf:type
>>> of something.
>>> Regards,
>>> Mark
>>> On 28/06/07, Ivan Herman <> wrote:
>>>> I am a bit uneasy with the usage of @class. _I know_ that the formal
>>>> semantics of @class allows this type of usage, and I also know that the
>>>> microformat community uses that trick, I still feel that usage @class is
>>>> putting a semantics into the attribute that a lambda user would not
>>>> expect. (And yes, I am also uneasy with the way the microformats reuse
>>>> attributes like title, class, or abbr...).
>>>> I would prefer to use a dedicated attribute if we need it (or simply
>>>> stick to the rel="rdf:type", which is at disposal anyway).
>>>> I must admit I am not fully familiar with the discussion behind @role to
>>>> decide whether @role should be introduced in RDFa for XTHML1, too, to
>>>> cover this usage, or whether a different @type or similar should be
>>>> introduced. I guess this discussion should start _if_ ISSUE-3 is not
>>>> resolved for @class
>>>> Ivan
>>>> P.S. Having said all that: I do not consider this issue as life
>>>> threatening:-) Ie, resolving it quickly is probably more important than
>>>> spending lots of time finding the best solution.
>>>> Ben Adida wrote:
>>>>> Another issue up for discussion.
>>>>> ISSUE-3
>>>>> The question is what @class and @role should yield in XHTML1.1+RDFa. We
>>>>> don't have complete consensus on this (we specifically note Steven
>>>>> Pemberton's worries about the reuse of the @class attribute), but the
>>>>> current solution, as accepted in the Primer and in many use cases,
>>>> is as
>>>>> follows:
>>>>> @class yields rdf:type only if the value is namespace-qualified. @class
>>>>> contains a space-separated list of values. Only those values which are
>>>>> namespace-qualified yield rdf:type triples.
>>>>> @role does not exist in XHTML1.1, so it is not used here. In XHTML2, it
>>>>> is expected to yield a triple with predicate xhtml2:role.
>>>>> +1 if you agree, otherwise email your disagreements and explanation.
>>>>> -Ben
>>>> -- 
>>>> Ivan Herman, W3C Semantic Web Activity Lead
>>>> URL:
>>>> PGP Key:
>>>> FOAF:


Ivan Herman, W3C Semantic Web Activity Lead
PGP Key:

Received on Thursday, 28 June 2007 14:17:32 UTC