[whatwg] Predefined classes are gone

Michel Fortin michel.fortin at michelf.com
Thu May 17 13:36:11 PDT 2007

Le 2007-05-17 à 13:54, Adrienne Travis a écrit :

> If we could NAMESPACE the predefined class names, that'd actually
> remove ALL my objections to the idea of overloading /class/ instead of
> creating a new attribute (/role/ or whatever). But unfortunately, that
> totally breaks backwards-compatibility if not done very carefully. (If
> i declare class="dc:author" , i CAN'T address that in my stylesheet.

Well, you *can*, but it's not a pretty selector:

     .dc\:author { }


     *[class~="dc:author"] { }

> If the namespacing was handled with dashes, like class="dc-author",
> that would work, though.)

So I suggest doing it like this:


which can be selected this way:

     .-dc-author { }

The idea of the leading dash is to avoid potential clashes with  
existing values: it's common today to separate two words inside a  
class name with a dash, it's much less common to start a class name  
with a dash. So perhaps the spec should reserve class names starting  
with a dash for namespacing purpose and define the meaning of those  
as the XHTML Role Module would have defined them with the semicolon  

I don't think in any way that this is incompatible with the  
predefined class names that were just removed (which I liked), it's  
just a little addition so you're not limited to the few predefined  
ones. The XHTML Role Module also has a couple of predefined global  
roles it seems.

Michel Fortin
michel.fortin at michelf.com

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