RE: Re: Experimental TESTxx header usage.

[Kevin Hawkins]

> -----Original Message-----
> From: mark_harrison_uk2 [mailto:<a
href="/group/xAP_developer/post?postID=YPoDDiBjVfU_X9j3F0KlpBqmCD6l407aVleuIISBiSTRTj7KEpcoCvhapBrUq6wiXtp7tVvvOknsRN5-">mph@a...</a>]
> Sent: 05 August 2003 22:50
> To: <a
href="/group/xAP_developer/post?postID=Z7QkDfNJldi1BW3xYGcp4jeSBaN97o-7o0PfOfsYeEpg9kbC_Twfv-ww9nuj2wWQbEmZKxwd6vVK7gULFpQr5JbBZd3P">xAP_developer@xxxxxxx</a>
> Subject: [xAP_developer] Re: Experimental TESTxx header usage.
>
> --- In <a
href="/group/xAP_developer/post?postID=Z7QkDfNJldi1BW3xYGcp4jeSBaN97o-7o0PfOfsYeEpg9kbC_Twfv-ww9nuj2wWQbEmZKxwd6vVK7gULFpQr5JbBZd3P">xAP_developer@xxxxxxx</a>,
"Ian B" <Ian@M...> wrote:
> > Hi all
> >
> > I am working from:
> > Specification Release v.1.2 - 29th November, 2002
> > Document Release v.1.2-9 (Final) - 1st December, 2002
> >
> > The word 'test' does not even occur in this document
>
> That's correct. The TEST headers were NOT ratified as part of the
> spec.

They were agreed and endorsed by the xAP specification committee - however
we did not include them in the document to avoid confusion and to
discourage
thoughtless usage of such a feature. Npw as xAP evolves we have seen some
areas that suggest we need them so I am stating the official way we agreed
to address this.

>
> I think that Kevin's proposal has the "official" status of a
> suggestion - it should not be regarded as an official part of xAP...
> HOWEVER...
>
> > Quote
> > A device should ignore all unknown name, value pairs included in
> the header.
> > /Quote
>
> Yup - that's what the xAP spec says - The reason for this was twofold:
>
> 1: a general agreement that we needed a mechanism in which potential
> Specicifaction extensions could be tested.
>
> 2: a general agreement that graceful fallback is a worthy design goal
> of any system.
>
> > In the embedded world [...] these surprises are not exactly
> > welcome.
>
> I don't think you can say that something that is printed in the spec
> is a "surprise" :-)
>
> > I validate deliberately strictly and the insertion of new
segments
> > breaks my code i.e. it will fail and ignore the message.
>
> Do we need a debate on what developers would prefer? A requirement
> for a graceful ignore vs. a hard set of header standards.
>
> I, for one, would be grateful if anyone considering using this could
> detail what the purpose of their new header items is, and why they
> are sufficiently generic so as to require entry in the header rather
> than just being in a specific class or schema for the application /
> message type in question?

I agree Mark and if you pass back through the recent archives on
this list you will see the ongoing discussions that we have been having
over
a variety of Topics that have individual threads numbered 1 to 5. The
conclusion on these is that we may need some header mechanisms for some of
these. Given the apathy on moving these forward I have suggested I act as a
coordinator for the lower block of Testxx to ensure a mutual understanding.
How people use the higher values is at their discretion but in my first
message of this thread I have stated quite clearly what I see the purpose
of
these to be. They are not for ill reasoned usage.

Mark, I would welcome your contribution to these Topic 1-5
discussions too.

Kevin