I'm torn; on the one hand, dcterms is already defined, and already
used in other feed formats; on the other hand, the syntax is less-
than-simple.
So, I'm neutral on this.
On 08/10/2005, at 7:37 AM, James M Snell wrote:
Ok all, after looking this over in detail, I personally still have
a preference for the age:expires and age:max-age elements in the
feed-expires spec. Of course, this is likely due more to the fact
that I wrote the draft as opposed to a sound, objective and
technical perspective. So I want to open it up to a poll.
Here are the options.
I wanted to indicate that a given entry must expire at Midnight on
Dec, 12, 2005 (GMT).
using age:expires:
<entry>
...
<age:expires>2005-12-12T00:00:00Z</age:expires>
</entry>
Advantage:
* The value of the expires element uses the Atom date construct
making it ALWAYS compatible with other Atom dates
Disadvantage:
* New namespace, new element
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.
So what do y'all think?
- James
Mark Nottingham wrote:
FWIW, the Media RSS extension cites http://web.resource.org/rss/
1.0/ modules/dcterms/#valid] as a best practice.
On 29/09/2005, at 4:45 PM, James Holderness wrote:
Just a follow-up on the representation of Date Ranges in dublin
core. I was under the mistaken impression that you needed to use
a DCMI Period encoding to represent a date range, but apparently
ISO 8601 time intervals are perfectly valid. In order to clarify
the situation, the DC Date Working Group has recently
recommended the following replacement for the comment associated
with the date element:
"Typically, Date will be associated with the creation or
availability of the resource. A date value may be a single date
or a date range. Date values may express temporal information at
any level of granularity (including time). Recommended best
practice for encoding the date value is to supply an
unambiguous representation of the single date or date range
using a widely- recognized syntax (e.g., YYYY-MM-DD for a single
date; YYYY-MM-DD/ YYYY-MM-DD for a date range; YYYY-MM-DDTHH:MM
to specify a single date and time down to the minute)."
Full details of the recommendation can be found here:
http://dublincore.org/usage/meetings/2005/09/madrid/files/
2005-07-29.date-comment.txt
Personally I think that makes the idea of using dublin core for
this extension a whole lot more palatable.
--
Mark Nottingham http://www.mnot.net/
--
Mark Nottingham Principal Technologist
Office of the CTO BEA Systems
--
Mark Nottingham http://www.mnot.net/
