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#foo URI references

From: Paul Grosso <pgrosso@arbortext.com>
Date: Wed, 25 Jun 2003 14:09:19 -0500
Message-Id: <4.3.2.7.2.20030625125209.0218c468@172.27.10.30>
To: uri@w3.org

Apologies for entering late, but I've just realized that the
latest 2396bis is planning to change the meaning that 2396 gives
to URI references that consist only of a fragment identifier.

I'm surprised to hear this is being considered, and I think it
is a mistake.

As I'm sure most of you 2396-experts know, from 2396:

   4.2. Same-document References
 
   A URI reference that does not contain a URI is a reference to the
   current document.

   . . .

   5.2. Resolving Relative References to Absolute Form

   . . .

   2) If the path component is empty and the scheme, authority, and
      query components are undefined, then it is a reference to the
      current document and we are done. 

   . . .

   C.1.  Normal Examples

   #s            =  (current document)#s


However, in draft-fielding-uri-rfc2396bis-03, the text in
4.4  Same-document Reference has been changed in this regard.

The pseudo-code in 5.2  Obtaining the Referenced URI includes:

 if (R.path == "") then
            T.path = Base.path;

And in 5.4.1  Normal Examples, there is:

  "#s"            =  "http://a/b/c/d;p?q#s"


The fact that several browsers have done this wrong for a long time
has been very annoying, but is not a good reason to remove this
needed feature.  Some browsers and other tools do follow 2396
properly in this regard.  

In fact, this specific issue was discussed in the development of 
the XML Base Recommendation [1].  When we made normative reference 
to RFC 2396 in XML Base, we did this with the clear understanding 
that we were defining XML Base so that a URI reference consisting 
solely of a fragment identifier would NOT be affected by XML Base.

So changing 2396bis in this respect would mean that 2396bis would
then be out of sync with XML Base.

Use case
--------
I download one part of a multipart W3C spec to my laptop so that I
can work on a new version of it.  This document has made intelligent 
use of relative URIs to make references to the other parts (and
graphics) that make up this spec.

I don't want to download the whole set of other parts and graphics
while I work on this part, so I set xml:base appropriately on the
document element so that all the relative URIs to the other parts
and graphics work. 

Of course, there are lots of relative URIs that are only fragment 
identifiers within this document.  This includes links from
citation elements in the text down to the corresponding bibliography
entry, links from tokens in various grammar productions over to another 
production within the same document, links from defined terms to it
definition within this document, etc.

I like the fact that, when I click on a link that resolves to 
another part, I am taken to that other part which is why I want
to use xml:base.  But I sure don't want to click on a link that's
supposed to take me from a defined term to its definition in the
previous paragraph and find myself going to another (older version
of the) document.  And if I'm offline and trying to work on this
document, I'm going to be even more inconvenienced when I click
on what I believe to be an intra-document link if it turns out
instead to refer to another resource that I cannot currently access.

If URI references of the form #foo are no longer going to be same 
document references, then I see no way to have the citation,
term/definition, or other intra-document links work in the presence
of xml:base.

Basically, this change would make use of XML Base (if we changed XML Base
to refer to the new version of 2396) difficult to the point of becoming
almost useless in documents that made much use of intra-document links.

paul

[1] http://www.w3.org/TR/xmlbase/
Received on Wednesday, 25 June 2003 15:13:44 GMT

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