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Re: On XPointer and the context-independence of URIs

From: Bjoern Hoehrmann <derhoermi@gmx.net>
Date: Sun, 21 Jul 2002 19:24:13 +0200
To: Dan Connolly <connolly@w3.org>
Cc: Norman Walsh <Norman.Walsh@Sun.COM>, www-tag@w3.org
Message-ID: <vdqljuke2na28lui89d3to04v3amu7q30e@4ax.com>

* Dan Connolly wrote:
>> That is, an XPointer of this form:
>> 
>>   <x:p>
>>     <x:a href="#xpointer(//x:div[3])">the third div</x:a>
>>   </x:p>
>> 
>> was deemed inappropriate because it relied on in-scope namespace
>> declarations to determine the fully qualified name of x:div.
>> 
>> The "correct" XPointer by this reasoning is:
>> 
>>   <x:p>
>>     <x:a href="#xmlns(x=http://www.w3.org/1999/xhtml)
>>                 xpointer(//x:div[3])">the third div</x:a>
>>   </x:p>

This is a rather bad example, XPointer currently cannot be used in
combination with XHTML documents (see RFC 3236) (well, ok, you cannot
even use them with XML documents until RFC 3023 gets updated) and you
cannot use xsd:anyURIs in XHTML documents, i.e., the white space
characters (space and line feed) are illegal and even for xsd:anyURIs
their use is strongly discouraged.

>> [...]
>> so I don't see how context-independence by itself is an unassailable
>> argument for requiring xmlns().
>
>Right, that's not the whole argument. The point is: the
>base URI context dependency is known to everything that
>knows about URI references. You can't introduce more
>context without teaching all the URI software...
>which is pretty much impossible.

What's the difference between both examples for software that does not
support XPointer? And why is the difference not an argument against
xml:base?

regards.
Received on Sunday, 21 July 2002 13:24:49 GMT

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