Re: Question about RDFa processing rule 8 (@typeof)

On Aug 27, 2010, at 15:14 , Christoph LANGE wrote:

> Dear RDFa WG members,
> 
>  I have a question about processing rule 8 from the latest draft (http://www.w3.org/TR/2010/WD-rdfa-core-20100803/), which says:
> 
>> If in any of the previous steps a new subject was set to a non-null value, it is now used to provide a subject for type values;
>> One or more 'types' for the new subject can be set by using @typeof. If present, the attribute must contain one or more URIs …

Actually, I believe that is an editorial bug. Per

http://www.w3.org/2010/02/rdfa/track/issues/13

and its resolution in 

http://www.w3.org/2010/02/rdfa/meetings/2010-04-08#resolution_2

it is allowed to have @typeof="", yielding a (typeless) Bnode. Ie, the text should say "the attribute may contain one or more URIs"

Ivan


>> 
>> …
>> 
>> Note that none of this block is executed if there is no new subject value, i.e., new subject remains null. 
> 
> But aren't the initial remark ("if … a new subject was set to a non-null value") and the last remark ("none of this block is executed if there is no new subject value") a bit redundant?  Processing rules 6 and 7 either determine a new subject e.g. from @about, or, if there is @typeof, they create a bnode.  Therefore it seems to me that the precondition of rule 8 is always satisfied, and rule 8 could be simplified to:
> 
>> If @typeof is present, the attribute must contain one or more URIs …
> 
> Or is there some catch that I am overlooking?
> 
> Cheers, and thanks for any help,
> 
> Christoph
> 
> -- 
> Christoph Lange, Jacobs Univ. Bremen, http://kwarc.info/clange, Skype duke4701


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Ivan Herman, W3C Semantic Web Activity Lead
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