Re: Optional Extensions

I don't think you can ever say that something MUST not fail.  I can choose
to fail on any condition I want, including using XML elements from a
particular namespace, running after closing time, etc.

I believe all we can say is that optional extensions may be safely ignored.

--Glen

----- Original Message ----- 
From: "Jeff Mischkinsky" <jeff.mischkinsky@oracle.com>
To: "Liu, Kevin" <kevin.liu@sap.com>; "'Prasad Yendluri'"
<pyendluri@webmethods.com>; "Glen Daniels" <gdaniels@sonicsoftware.com>
Cc: "Web Services Description" <www-ws-desc@w3.org>
Sent: Wednesday, January 28, 2004 2:01 PM
Subject: RE: Optional Extensions


> At 10:18 AM 1/28/2004, Liu, Kevin wrote:
>
> >I see the value of both sides of the argument. From the service
> >perspective, assurance of backward compatibility is
> >desireable(non-required extension will not break its current clients);
> >from the service users perspective, it maybe a good thing to be at least
> >warned that some not-understandable optional extension is encountered.
> >
> >In stead of saying that the processor MUST *ignore* the
not-understandable
> >optional extension, would it be better to say that the process MUST NOT
fault?
>
> I like this better. But what happens if i want to be super-strict/paranoid
> and implement a policy (lower case policy :-) and be very sure that I
> understand everything in my environment, i.e. i'm not willing to trust
> someone that something is ignorable. What are my choices if we go down
this
> path? Is my only alternative to be non-compliant?
>
> cheers,
>    jeff
>
>
> >Best Regards,
> >Kevin
> >
> >
> >-----Original Message-----
> >From: www-ws-desc-request@w3.org [mailto:www-ws-desc-request@w3.org] On
> >Behalf Of Prasad Yendluri
> >Sent: Tuesday, Jan 27, 2004 02:15 PM
> >To: Glen Daniels
> >Cc: Web Services Description
> >Subject: Re: Optional Extensions
> >
> >
> >
> >
> >
> >Glen Daniels wrote:
> >
> > >I'm sorry, but I don't understand this whole "may ignore them"
business.
> > >What exactly is a processor going to do with an extension it doesn't
> > >understand?  IMHO, it has to ignore them unless they are marked as
> > >required, in which case it fails.
> > >
> >It *can* give an option to a user of the tool to decide if it should go
> >ahead ignoring the extensions it did not understand even if they are
> >optional extensions or minimally issue a warning message (as a
> >configurable option say). Blindly ignoring and staying silent on the
> >user is the worst thing a tool can do to a user. I may want to build a
> >client that understands certain optional extensions I need to use. If
> >the tool does not handle some of the extensions, I as a programmer may
> >like to have an option to override and plug in my code as needed or at
> >least be notified.
> >
> >That way I can decide to buy tool-A that does not understand all the
> >extensions vs Tool-B that does. May be some tool builders :-D would not
> >like that.
> >
> >Just putting forth a pragmatic perspective for discussion. Grab some
> >cool-aid will you!!!
> >
> > > I think this is common sense, but it
> > >wouldn't hurt to specify it either.
> > >
> >Common sense tells me not to blow my top off silly also :)
> >
> > >
> > >--Glen
> > >
> > >
> > >
>
> Jeff Mischkinsky                      jeff.mischkinsky@oracle.com
> Consulting Member Technical Staff     +1(650)506-1975
> Director, Web Services Standards      500 Oracle Parkway M/S 4OP9
> Oracle Corporation                    Redwood Shores, CA 94065
>
>

Received on Wednesday, 28 January 2004 14:54:10 UTC