- From: Chimezie Ogbuji <ogbujic@ccf.org>
- Date: Fri, 15 Jun 2007 09:39:32 -0400
- To: "Jeremy Carroll" <jjc@hpl.hp.com>
- cc: public-grddl-wg@w3.org
On Fri, 2007-06-15 at 11:53 +0100, Jeremy Carroll wrote: > 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 I don't think this would work, since E is the link element itself (where the @href and @rel attributes are defined) and N is the root node. XML Base gives a mechanism for assigning a base IRI "in context" (i.e., from the link element, to the head element, and up to the html root element). The XHTML Base module provides a universal base URI for resolving relative references. Why would we want to remove the context? It doesn't seem in the spirit of XML Base. > 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)) If we follow John's earlier [1] assumption (which is the same as mine) about XHTML Base: "Note that I am assuming that in XHTML, xml:base *is* supported, since XHTML is a proper XML dialect." Then wouldn't that be in conflict with the suggested change? > 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. Is this really the case? If XHTML doesn't support xml:base then is it an XML dialect or independent markup with an XML serialization? If it is the former, *should* it really have application/xhtml+xml as its media type? > 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. It only fails if there is an xml:base in an XHTML document, which *seems* to be an undefined combination. > 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". I agree. > 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. The only issue is when used in combination with an XHTML Base. It is hard to know what to tweak to adequately describe an undefined situation. At least, stating that the relative URI resolution happens WRT the immediate context allows processors which honor xml:base in all cases to do so. > 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. Perhaps the base appendix should highlight why use of xml:base with XHTML Base is undefined, but be explicit about other scenarios and their relationships with XML Base, XHTML Base, and RFC 3986? [1]http://lists.w3.org/Archives/Public/public-grddl-wg/2007Jun/0083.html -- Chimezie Ogbuji Lead Systems Analyst Thoracic and Cardiovascular Surgery Cleveland Clinic Foundation 9500 Euclid Avenue/ W26 Cleveland, Ohio 44195 Office: (216)444-8593 ogbujic@ccf.org =================================== Cleveland Clinic is ranked one of the top 3 hospitals in America by U.S.News & World Report. Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. 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Received on Friday, 15 June 2007 13:40:02 UTC