Re: FW: issue-dbooth-4f: Sec 4, base IRI of an element

Summary:

two possible suggested changes:

1) change the normative text from
"the base IRI of E" to "the base IRI of N"
in the specific rule
http://www.w3.org/2004/01/rdxh/spec#rule_tlrel
or
2) change the informative text, after the rule from:
"Note that the base IRI of an element node in an XHTML document may be 
influenced by factors such as a base element[HTML4] Retrieval 
URIRFC3986, etc. See test cases such as htmlbase1 for further 
clarification."
to
"Note that the base IRI of an element node in an XHTML document
is the base IRI of the document and may be influenced by factors such as 
a base element[HTML4] Retrieval URIRFC3986, etc. See test cases such as 
htmlbase1 for further clarification."

(In case 1, the informative text would need a small tweak too)
(my preference is (2))

========================


I think this comment has some merit
http://lists.w3.org/Archives/Public/public-grddl-comments/2007AprJun/0100

My understanding is that:
- GRDDL depends on XML Base in section 2
- XML Base does define a base URI for every element
- the language in section 2 is appropriate

But in section 4, XHTML does not implement XML Base, and hence in XHTML 
documents XML Base is illegal, and a user-agent (including a GRDDL aware 
agent) should either flag the error or ignore it.

Hence, the wording in
http://www.w3.org/2004/01/rdxh/spec#rule_tlrel
"the base IRI of E"
is slightly misleading, and might result in interoperability failures 
with a document in the xhtml namespace, that does include an xml:base.

To some extent this is a GIGO problem.
If someone mistakenly believes that XML Base is supported by XHTML then 
they are likely to find different implementations behaving differently. 
It is, in general, reasonable for a generic XML processor to assume that 
if the document author has used xml:base then it has been used legally, 
and not reasonable to expect a generic XML processor to know which 
document formats support xml:base and which don't and to flag errors of 
the form, "xml:base has been used inappropriately".

Section 2 thus does (and should, in my view) honour xml:base.

Section 4, which is specifically about XHTML should not. However, the 
normative rule is written in greater generality (i.e. any XPath node set 
with a metadata profile, although metadata profiles are only defined for 
XHTML)

I think my preference, at this stage, would be to tweak the informative 
text. I fully expect interoperability failures in this case, but that is 
because of the confusing state of when xml:base can and cannot be used, 
and that is not within this group's control or remit.

Whether this issue should be further called out in the (possible) new 
base appendix, I am unclear. I think it is more important that at least 
some implementations flag the error (using xml:base inside an HTML doc) 
than the exact wording of the spec.

Jeremy



Booth, David (HP Software - Boston) wrote:
> I meant to send this to the regular WG list.  I did not intend it as a
> formal comment.  
> 
> AFAICT this looks like an editorial issue.  Can anyone shed light on it?
> Shouldn't this refer to the base IRI of the XML document?
> 
>> From: Booth, David (HP Software - Boston) 
>>
>> P.S. I notice that RFC3986 refers to the "base URI of a 
>> representation":
>> http://www.ietf.org/rfc/rfc3986.txt
>>
>>
>> David Booth, Ph.D.
>> HP Software
>> +1 617 629 8881 office  |  dbooth@hp.com
>> http://www.hp.com/go/software
>>
>> Opinions expressed herein are those of the author and do not 
>> represent the official views of HP unless explicitly stated otherwise.
>>  
>>
>>> -----Original Message-----
>>> From: public-grddl-comments-request@w3.org 
>>> [mailto:public-grddl-comments-request@w3.org] On Behalf Of 
>>> Booth, David (HP Software - Boston)
>>> Sent: Tuesday, June 12, 2007 6:25 PM
>>> To: public-grddl-comments@w3.org
>>> Subject: issue-dbooth-4f: Sec 4, base IRI of an element
>>>
>>>
>>> In Sec 4
>>> http://www.w3.org/2004/01/rdxh/spec#rule_tlrel
>>>
>>> The normative definition of GRDDL transformation mentions 
>>> "the base IRI
>>> of E" , but E was defined as "the head element".  Does "the head
>>> element" have a base IRI?  A quick scan of the XHTML spec at
>>> http://www.w3.org/TR/xhtml1/ shows no mention of base URI.  
>>> The XML spec
>>> http://www.w3.org/TR/REC-xml/ mentions the "base URI of a 
>>> resource".  Is
>>> the concept of a base URI of an element supposed to be defined
>>> somewhere, or is this an editorial error?
>>>
>>> Come to think of it, I guess this question also applies to 
>>> the section 2
>>> definition of GRDDL transformation:
>>> http://www.w3.org/2004/01/rdxh/spec#rule_GRDDL_transformation
>>>
>>>
>>> David Booth, Ph.D.
>>> HP Software
>>> +1 617 629 8881 office  |  dbooth@hp.com
>>> http://www.hp.com/go/software
>>>
>>> Opinions expressed herein are those of the author and do 
>> not represent
>>> the official views of HP unless explicitly stated otherwise.
>>>
>>>
> 

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Received on Friday, 15 June 2007 10:54:04 UTC