Re: Changing atom:id

["A. Pagaltzis" <pagaltzis@xxxxxx>]

Hi Brian,

it isn’t quite that stringent. Even at that theoretical level,
the server might be accepting an entry that exists, or creating a
new one with identical content; the spec doesn’t say which one.
Which ID is assigned at POST time is therefore not knowable.

What to do about the ID was actually a topic of long debates
among the working group; one of the options considered (but
rejected) was defining a new media type for entry documents
wherein the ID as well as some other aspects are optional.
(Considering that we ended up with a `type` parameter being
required, and in light of the two-entry confusion that Sylvain
referred to, that looks like an attractive option in retrospect.
Oh well; perfect is the enemy of good.)

In practical terms, you cannot absolutely say that the ID MUST
NOT be changed on PUT either, because we’re not working on some
platonic plane where information is pure and abstract. (If you
insist, you eventually end up with string theory; lots of
distinctions without a practical difference.) However theory is
helpful as a guide, and in case of the ID it is in place because
it allows particular assumptions. It is pretty clear that letting
people change IDs willy-nilly weakens those assumptions, so does
not make for a useful implementation. Since there is no good use
case to make up for that loss, the vote should be nay on that.

Regards,
-- 
Aristotle Pagaltzis // <http://plasmasturm.org/>