On Mon, 13 Mar 2000 08:02:11 PST, ned(_dot_)freed(_at_)innosoft(_dot_)com said:
Specifically, in order for this to work sending agents have to generate a
field
saying "this thing is XML". In order to do tis they have to have a list of all
XML-based types. And this is exactly the list we're trying to avoid having.
Huh?
If I have a sending agent that knows how to generate a foobar type, and
a foobar-using-xml type, then *whatever* scheme we use to flag xml, I
have enough information to flag that THIS type is xml. I don't need to
know whether a frobozz-using-xml type exists, or is registered, or is
being used via private agreement with x-frobozz types.
Compare this with embedding this information in the content-type. There's
already a list of (some file characteristic)->content-type mappings in most
MIME applications. So no new list is needed. The information simply gets
embedded in the existing list.
There's only one snag here - semi-legacy software. If we decide that
we should just use application/xml and tehn a Content-Feature: or
whatever tag to flag specific ideosyncracies/schemas for the object,
then once deployed, a receipient will be able to get at *least* the
base application/xml level of support no matter WHAT future updates of
his software he makes. I thought the whole point of XML was that the
reciepient will be able to do basic operations (such as "hmm.. forward
all THIS stuff tagged with finance schema to Fred, and all the
stuff that looks like shop-floor-machining stuff to Larry") without
knowing what the heck the data IS.
If you start using application/iotp-xml, and application/foo-xml,
and application/frobozz-xml, until the recipient updates his table,
he gets punted ALL the way back to application/octet-stream.
That's a phone call to our help desk to figure out how to open
this unidentified file. Then another to find out how to install
the table update for foobar-xml. Then another to find out how
to install the application to get rid of the "application not found"
box.... You get the idea. ;)
/Valdis (who left user services mostly because he hated those kinds
of phone calls ;)