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Re: Why I don't like 'instanceof' (was Re: [RDFa] ISSUE-3: syntactic sugar for rdf:type)

From: Keith Alexander <k.j.w.alexander@gmail.com>
Date: Fri, 20 Jul 2007 11:33:24 +0100
To: "Ivan Herman" <ivan@w3.org>, "Hausenblas, Michael" <michael.hausenblas@joanneum.at>
Cc: "Steven Pemberton" <steven.pemberton@cwi.nl>, "Ben Adida" <ben@adida.net>, RDFa <public-rdf-in-xhtml-tf@w3.org>, "SWD WG" <public-swd-wg@w3.org>
Message-ID: <op.tvrd9ygn63ayaz@keith-alexanders-computer.local>

This may be late in the day to say this, but I liked @class.

It makes it easier to do 'semantic css', which means less bloated markup -  
which is easier to write and maintain. I think it is a good move to make  
RDFa enable 'really semantic' class names for CSS and javascripts  
(libraries like jQuery make it convenient to use classnames as hooks by  
mimicking the css syntax) to hook into.

I think it would be easier to sell RDFa the more you can co-ordinate it  
with current practice.

With @class, I can mark up my content with RDFa, and already have a bunch  
of classnames to style. Otherwise, I have to go back to the markup and add  
lots of classnames, which will be saying much the same thing as the  
@instanceof. In a way, it's penalising people who want to use semantic  
hooks for css, because they have to describe everything twice.

Even when web designers can rely upon browsers supporting attribute  
selectors, the classname syntax is still more convenient (even if one has  
to escape the colon in RDFa-style classnames).

Personally, I don't think there is a huge conceptual problem with whether  
the @class is describing the element or the resource the element  
represents. You could see it as: the div has the classification  
'foaf:Person' (understood as a literal), and the resource has the  
classification 'http://xmlns.com/foaf/spec/Person' (the uri represented by  

Failing @class, I'd vote for something as transparent as possible, like  


Received on Friday, 20 July 2007 11:12:36 UTC

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