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[css3-selectors] Default namespace and implied universal selector

From: Allan Sandfeld Jensen <kde@carewolf.com>
Date: Thu, 21 Apr 2011 12:30:11 +0200
To: www-style@w3.org
Message-Id: <201104211230.11840.kde@carewolf.com>

I have a comment/request for clarification to the default namespace rule 
effect CSS selectors, that recently bothered me. I am not sure if it belongs 
only in CSS Selector Level 3 specification or is also relevant to the CSS 
namespace specification.

The question is if the implied universal selector in the presence of a default 
namespace, like an explicit universal selector should be interpreted as ns|*.
I personally believe this is the case, but could find no text explicitly 
stating that.

It is stated that the universal selector without a namespace part should be 
treated as ns|* if a default namespace has been declared, and it is later 
stated that the universal selector can be omitted if there is more than one 
simple selector in a simple selector sequence. It is however not clear if the 
later statement that the universal selector can be omited, is a requirement 
meaning implied and explicit universal should always be treated identical, or 
if it is just an observation. In general the namespace rules seems kind of 
'tacked on' and not really integrated into the text.

The difference becomes more important when it is later stated that the default 
namespace does not affect attribute-selectors, but in a sense they do if the 
attribute selector stands alone. For instance: [attr], in the presence of a 
default namespace means select elements with types in the default namespace if 
they have an attribute 'attr' in the empty namespace.

Am I reading the spec correctly, and could the consequences of default 
namespace on implied universal selectors be made more clear?

Best regards
Received on Thursday, 21 April 2011 10:30:42 UTC

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