A. Pagaltzis wrote:
* Sjoerd Visscher <[EMAIL PROTECTED]> [2005-07-18 11:50]:
Yes, your <link href="" /> resolves to
http://www.tbray.org/ongoing/ But if you say "follow that link"
in a program with same-document references support, it will
say: "Ok, the link points to http://www.tbray.org/ongoing/, and
the base URI is http://www.tbray.org/ongoing/ as well, so I
have to return the current document instead of doing a new
request."
He is correct, Tim. The base URI means “the URL where this
document was found,” not “the prefix for any enclosed relative
links.” I don’t see how RFC3986 can be read any other way.
I am correct ;), but your explanation is wrong. 5.1 says clearly that
the "Base URI embedded in content" precedes any other way of
establishing a base URI. So the base URI is
<http://www.tbray.org/ongoing/>, and the empty relative URI therefore
refers to <http://www.tbray.org/ongoing/>.
But now the "URI reference refers to a URI that is, aside from its
fragment component (if any), identical to the base URI", so it is a
same-document link, and when "a same-document reference is dereferenced
for a retrieval action, the target of that reference is defined to be
within the same entity (representation, document, or message) as the
reference; therefore, a dereference should not result in a new retrieval
action."
It is a very complicated way of calculating that an empty relative URI
is always the current document, no matter what the base URI is.
So it would be
<feed xmlns='http://www.w3.org/2005/Atom'
xml:base='http://www.tbray.org/ongoing/ongoing.atom'
xml:lang='en-us'>
<title>ongoing</title>
<link href='./' />
<link rel='self' href='' />
...
<entry xml:base='When/200x/2005/07/14/Atom-1.0'>
If you want it to be perfect xml:base on the entry would be the URI of
the Atom Entry Document. And the html base URI should go on the xhtml
div element. Just like you get when the entries and the div elements are
XIncluded.
If we wanted to avoid this, we should have added language to the
spec that atom:[EMAIL PROTECTED]'alternate'] should never be considered
a same-document reference, maybe.
If your XML package has support for data-typing, xml:base and
same-document references, then you could no longer do
Node n = link.getAttribute("href").dereference();
because Atom would no longer follow standard behaviour.
--
Sjoerd Visscher
http://w3future.com/weblog/
