error in SSAP v1.2 extension schema

[Markus Demleitner]

Hi Paul,

On Thu, Aug 23, 2018 at 11:05:27AM +0000, Paul Harrison wrote:
> there is an error in the SSAP extension schema that is delivered
> for the http://www.ivoa.net/xml/SSA/v1.1 namespace  (which is in
> fact v1.2 of the schema). This schema file has an element
> ProtoSpectralAccess defined which is erroneously an extension at
> line 958 of ssap:SSACapRestriction which does not exist in the
> schema.

Ouch.  My bad.  For SimpleDALRegExt 1.1, we dropped the restriction
(that fixed the standardID, which kept people from using the SIA
extension to register SIAv2 services).  I ran an XML validator on the
schema file, which doesn't catch this.

Regrettably, even loading the schema into an (lxml-based) schema
processor doesn't flag the issue, so I again haven't noticed it.  Hm.
I can't say I understand why that is, and I don't have time just now
to try and figure it out.

> I guess this is all an attempt to correct the original ugly
> extension schema design - however, could ProtoSpectralAccess not be
> just dropped?

Well, there were still ProtoSpectralAccess capabilities out there
at the time of SimpleDALRegExt 1.1, so I didn't dare to throw it out.
Thankfully, it they have died out by now:

gavo=# select * from rr.capability where cap_type like '%ProtoSpectralAccess';
 ivoid | cap_index | cap_type | cap_description | standard_id 
-------+-----------+----------+-----------------+-------------
(0 rows)


By the book an incompatible change like removing a type is verboten
for a minor version change. Also, we could solve the issue by the
milder means of inheriting directly from vr:Capability, which would
keep us out of the tempting grey zone of bending the rules.

But having ProtoSpectralAccess part of the standard has been painful
all along.  I'd argue that removing something that shouldn't have
been there, that is no longer used, that should not be used in the
future, and the removal of which will make this work a better place
shouldn't be blocked by the TCG.

Does anyone want to protest?  If not: Paul, do you feel like writing
an Erratum for the removal?[1]

Thanks,

          Markus

[1] Just to get technicalities out of the way:  Errata go on the Wiki
these days, in a format like the one in

http://wiki.ivoa.net/twiki/bin/view/IVOA/TAPRegExt-1_0-Erratum-01

The URI of this Erratum would be

http://wiki.ivoa.net/twiki/bin/view/IVOA/SimpleDALRegExt-1_1-Erratum-01