- From: Henri Sivonen <hsivonen@iki.fi>
- Date: Mon, 12 Oct 2009 10:22:21 +0300
- To: Manu Sporny <msporny@digitalbazaar.com>
- Cc: HTMLWG WG <public-html@w3.org>
On Oct 10, 2009, at 22:02, Manu Sporny wrote: > Henri Sivonen wrote: >>> My recollection of the TF's discussion around @version is that it >>> was >>> a way to allow RDFa consumers to decide whether they wanted to >>> parse a >>> page or not. >> >> It seems that you failed to allow it. > > Perhaps the current RDFa Syntax spec isn't clear enough on this > matter. > We could add something as an Erratum. Could you please state some spec > text that would "allow it"? I opt not to use my time for drafting proper text for doing something that I think is in itself improper. That is, I think you shouldn't have @version at all for RDFa and I especially think (X)HTML (or SVG or MathML) should not have @version at all. >>> But you are right that from a *versioning* perspective, we don't >>> need >>> to indicate a version until there is some different processing to do >>> -- such as a difference between a version 1.1 and 1.0. >> >> But if you do need a version indicator for 1.1, wouldn't the >> problem of >> not completely controlling the page arise again? How is a version >> indicator for 1.1 supposed to work in Planet syndication? > > You wouldn't /need/ a version indicator for 1.1. @version isn't a > MUST... it is a SHOULD. If the @version indicator wasn't specified on > the page, but the User Agent still decided to extract RDFa from the > page, then the latest RDFa processor rules known to the User Agent > should be used. So, if RDFa 1.1 were the latest version... the RDFa > 1.1 > rules would be used to extract the data from the page. That's an interesting way of doing versioning especially when the current practice (as analyzed by Philip) is that RDFa-in-"XHTML"- served-as-text/html authors don't include a version attribute at all. When RDFa 1.1 is published, how do you expect legacy content to gain a version 1.0 version identifier all of a sudden? If you don't expect it to gain a version 1.0 identifier, how is the situation different from not having the version attribute at all? > The difference is that authors aren't given the option to specify a > version that is meaningful in HTML5... as most every HTML-family > document (whether it is HTML 3.0, 3.2, 4.02, XHTML 1.0 or XHTML 1.1) > now > becomes an (X)HTML5 document by default... More to the point, the old documents are processed according to the HTML5 processing rules. That's a feature, not a bug. (It's not particularly useful to discuss if the abstract essence of the existing documents changes from valid HTML.old to invalid HTML5. New documents should be written to be valid HTML5, though.) >> In any case, it's more relevant if any existing RDFa consumers (by >> default) modify their behavior when they get a version identifier >> from >> the future. Do they? (Philip's IRC remarks suggest they don't.) > > What do you mean by this question? Are you saying, if an RDFa > processor > today sees this: > > <html version="XHTML+RDFa 1.1"> > > does it do anything? I mean: If an RDFa 1.0 processor sees version="XHTML+RDFa 1.1", does it do anything differently compared to not seeing a version attribute at all. > That being said, with @version with /could/ change that feature in the > future without creating a backwards compatibility nightmare... without > @version, we will never be able to change that feature. How? (Given the current reality of the absence of @version in existing content and your statement that future RDFa processors would default to the latest version.) > Henri Sivonen wrote: >> On Sep 29, 2009, at 15:43, Toby Inkster wrote: >>> But there's also nothing in the syntax document that requires it to >>> *start* processing. So an RDFa processor can simply opt to not begin >>> processing, depending on whatever factors it wants. >> >> It seems like a spec bug if main() { exit 0; } is a conforming RDFa >> processor. > > Yes, quite clearly that would be a spec bug. However, I don't believe > that is what Toby was driving at... > > I believe that Toby meant to say "So, a ***User Agent*** can simply > opt > to not begin processing, depending on whatever factors it wants." > > /Something/ has to trigger the start of RDFa processing. Typically, > that > /something/ is the User Agent (or Application). So, in black-box terms, is |main() { exit 0; }|, in your opinion, a conforming User Agent that embeds an RDFa processor? This UA just happens never to opt to trigger the start of RDFa processing. -- Henri Sivonen hsivonen@iki.fi http://hsivonen.iki.fi/
Received on Monday, 12 October 2009 07:23:10 UTC