Sorry to note the obvious, but does this not sound so much like a
good reason we should
have engineered atom to *be* RDF? Is this not exactly one of the many
problems that RDF
sets out to solve?
Henry Story
On 10 Aug 2005, at 02:34, Tim Bray wrote:
On Aug 9, 2005, at 5:11 PM, David Powell wrote:
No, we just need to warn publishers (and extension authors) that the
base URI of Simple Extension elements is not significant, and that
they must not expect it to be preserved.
Either the software understands the foreign markup, in which case
it might recognize a relative URI, in which case it should apply
the correct base URI, or it doesn't, in which case everything in
the foreign markup is just a semantics-free string.
The problem could hypothetically arise when someone extracts
properties from the foreign markup, stuffs them in a tuple store,
and then when the software that knows what to do with comes along
and retrieves it and recognizes the relative URI and can't do much
because the base URI is lost.
So... IF you know how to handle some particular extension, AND IF
you expect to handle it when the extension data has been ripped out
of the feed and stored somewhere without any context, THEN you
shouldn't use a relative reference. Alternatively, IF you want to
empower extensions to process they data they understand, AND IF you
want to rip that data out of the feed and store it somewhere, THEN
it would be smart to provide software an interface to retrieve
context, such as feed-level metadata and the base URI.
Sounds like implementor's-guide material to me.
And, to whoever said relative references are "fragile": Wrong.
When you have to move bales of web content around from one place to
another, and just supposing hypothetically that you have internal
links, relative references are robust, absolute URIs are fragile. -
Tim
