Re: [forces] draft-ietf-forces-model-extension

Greetings Julian,

Apologies for the late reply.

As Jamal and Joel both noted, the model does not affect the protocol at all.

The change of the namespace was suggested by Adrian during his AD review
(https://www.ietf.org/mail-archive/web/forces/current/msg04837.html) which I
agreed to. I am more comfortable with keeping the new namespace as that will
clearly specify that extensions are expected.

Now, how about if we added the following text in the document. Would that
address your concerns?

"The extensions described in this document, are backwards compatible in
terms of the operation of the ForCES protocol.  In terms of the XML, any
definitions that were valid under the old name space are valid under the new
namespace.  It is to be noted that any auxiliary tools that are processing
xml definitions written under both namespaces will need to be able to
understand both."

Regards,
Evangelos Haleplidis.

> -----Original Message-----
> From: forces [mailto:forces-bounces@ietf.org] On Behalf Of Joel
> Sent: Thursday, October 23, 2014 5:05 PM
> To: Julian Reschke; Jamal Hadi Salim
> Cc: Amanda Baber; forces@ietf.org; Graham Klyne; draft-ietf-forces-
> model-extension@tools.ietf.org
> Subject: Re: [forces] draft-ietf-forces-model-extension
> 
> The XML in the draft is NOT carried over the wire.  It is a definition
> of structures which is referenced by the protocol carried over the
> wire.
> 
> Yours,
> Joel
> 
> On 10/23/14, 8:42 AM, Julian Reschke wrote:
> > On 2014-10-23 13:51, Jamal Hadi Salim wrote:
> >> On Wed, Oct 22, 2014 at 9:10 AM, Julian Reschke
> >> <julian.reschke@gmx.de> wrote:
> >>> On 2014-10-22 14:54, Haleplidis Evangelos wrote:
> >>>>
> >>>> Greetings Julian,
> >>>>
> >>>> I'm a little confused on why you think there is no backwards
> >>>> compatibility.
> >>>>
> >>>> LFB definitions that use the 1.0 namespace are valid in the 1.1
> >>>> namespace.
> >>>
> >>>
> >>> Unless I'm missing something: no, they are not.
> >>>
> >>> Can you provide a 1.0 example, and show how it is valid according
> to
> >>> the 1.1 schema?
> >>>
> >>
> >> I am trying to understand the issue.
> >> There is no namespace version carried in the protocol. And there is
> no
> >> changes in the protocol encoding as the result of the new namespace.
> >> IOW, it does not affect anything from the protocol perspective.
> >
> > Now I'm very confused. The XML defined by the draft is not carried
> over
> > the wire?
> >
> >> I can see a challenge with toolkits that look at the new namespace
> vs
> >> old.
> >> Old toolkits wont be able to understand the semantics of the new
> >> namespace.
> >
> > Right. So this is *not* backwards compatible. A message using the 1.1
> > namespace will not be processable by a recipient that expects the 1.0
> > namespace.
> >
> >> New toolkits should be able to understand the semantics of both old
> and
> >> new extensions - if the author chooses to. If i understood Evangelos
> >> correctly: He is saying the content inside the new namespace is
> basically
> >> backward compatible. If i understood you correctly, you are saying
> the
> >> moment you say it is version 1.1 you cant talk about the content
> inside
> >> and compare it with 1.0.
> >
> > You could, but it simply means that you need to write code that knows
> > about both namespaces. (I understand that it's not hard to do, but it
> is
> > very different from having nothing to do).
> >
> >> All the new extensions introduced are optional. And correctly
> written
> >> s/ware will log/ignore/bailout on extensions it doesnt support.
> >> Are you suggesting we keep the version at 1.0?
> >
> > If the rule for the 1.0 namespace is to ignore unknown elements then
> > indeed it doesn't make any sense to define a new namespace.
> >
> >> How does one detect there's new extensions?
> >
> > By inspecting the element name and see whether it's known?
> >
> > Best regards, Julian
> >
> > _______________________________________________
> > forces mailing list
> > forces@ietf.org
> > https://www.ietf.org/mailman/listinfo/forces
> 
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