Oops, sent this from the wrong address on Saturday. No wonder it
didn't get through.
On Oct 8, 2005, at 8:37 AM, James M Snell wrote:
I wanted to indicate that a given entry must expire at Midnight on
Dec, 12, 2005 (GMT).
using age:expires:
[snip]
using dcterms:valid (http://web.resource.org/rss/1.0/modules/
dcterms/#valid)
<entry>
<dcterms:valid>end:2005-12-12T00:00:00Z</dcterms:valid>
</entry>
Advantage:
* Existing namespace, known element
Disadvantage:
* Value can be many different things. I've even seen cases in
which the content of dcterms:valid is an XML structure.
My chief problem with dcterms:valid (and with dublin core in
general) is that the elements are very loosely defined. The
content can literally be anything folks want it to be and still be
considered valid. Unless we constrain the value space for this
element when used in Atom, it *could* lead to a bunch of extra work
for consumers to parse and process those dates. I prefer very
crisply defined elements. Then again, reusing an existing
namespace is Goodness.
I think it would be going too far to say "when using dcterms:valid in
Atom, you must follow this profile", because we don't own dcterms,
and doing so might limit people from doing valid things with it that
don't follow that profile. But I do think it would be reasonable to
say "when using dcterms:valid in Atom, it is recommended that you
follow this profile--otherwise your data may be technically valid,
but not widely understood", thus giving developers an excuse for not
supporting data not formatted according to that profile. If a use
case that requires a different format becomes common, then developers
can start supporting more formats at that point.
That said, my "vote" is for doing what I just said--advocate the use
of dcterms:valid for this purpose, with the date formatted to match
Atom's date construct profile.
BTW, you might choose language that leaves room for having both start
and end dates for validity--for example, to enable Atom delivery of a
coupon that's valid for a particular span of dates.
