W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > December 2007

Small change to the relationship between head and body during parsing

From: Mark Birbeck <mark.birbeck@x-port.net>
Date: Thu, 20 Dec 2007 12:16:20 +0000
Message-ID: <a707f8300712200416o2886bb9ck9e044767aa8d414f@mail.gmail.com>
To: "W3C RDFa task force" <public-rdf-in-xhtml-tf@w3.org>

Hello everyone,

I've made a small change in the draft to the way that processing
occurs in terms of the hierarchy. Ordinarily I'd propose this to the
group, have discussion, etc., but given we are up against it in terms
of time, I've put it straight into the draft in a self-contained
block, so that if the consensus is against what I'm suggesting, it is
easy to simply remove it.

I'll explain the changes first, and then the justification. The change
is in a note, as follows:

<div class="explanation">
Note that since the head contains information that determines how the
body should be parsed, the [evaluation context] as set at the end of
processing <code>head</code> is then passed to the processing of
<code>body</code>. It is <em>as if</em> instead of the DOM looking
like this:
document object
  |__ html
        |__ head
        |__ body

it looked like this:

document object
  |__ html
        |__ head
              |__ body

In current documents this is unlikely to make any difference at all.
However, my motivation for doing this is so that any [URI mappings]
that are set in <head> get passed on to <body>. This allows us to
invent some new scheme in the future, such as:

  <link id="dc" rel="prefix" href="http://purl.org/dc/elements/1.1/" />

or whatever we come up with, and have the prefixes apply across the
document. With the current parsing model that wouldn't work.

Note that this is important for a number of reasons:

  * when we come to look at HTML we can do CURIEs without having to rely
    on @xmlns;

  * there was a lot of opposition to using XML namespaces _anyway_;

  * it is actually more 'logical', since the head does already set
information for the
    document that could not be determined by applying a simple
hierarchical processing
    model (for example, <base> would not apply to the entire document);

  * the IPTC had a lot of problems with the prefix mapping question,
because they
    wanted to be able to refer to a great big block of prefix
mappings, sometimes in
    an external document, and this technique would allow that.



  Mark Birbeck, formsPlayer

  mark.birbeck@formsPlayer.com | +44 (0) 20 7689 9232
  http://www.formsPlayer.com | http://internet-apps.blogspot.com

  standards. innovation.
Received on Thursday, 20 December 2007 12:16:29 UTC

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