SSA validator

[Douglas Tody]

On Fri, 25 Jan 2013, Pierre Le Sidaner wrote:

> I am currently updating my SSA validator at VOParis. Looking at this link
>
> http://wiki.ivoa.net/twiki/bin/view/IVOA/ServiceValidation
>
> I see that *4.2.5* The RESOURCE containing the results of a response to a 
> valid query must include one FIELD / PARAM element with: UCD mandatory
> In the SSA document 1.1 and older only Utypes are mandatory not UCD
> even in the SSA document 1.1   on  4.2.1
> UTYPEs of standard fields are required for identification of interface 
> elements and *must* be given and *must* comply with the SSA protocol (this 
> document) /.../ UCDs *should* also be given when specified by the protocol
> So do you want me to ignore the document Service Validator and validate what 
> is in the protocol document 
> http://www.ivoa.net/Documents/SSA/20120210/REC-SSA-1.1-20120210.htm

SSA uses UTypes to identify data model fields (that is what they are
for), however a special case is the flux or spectral axis coord type
which would be identified with a UCD.  Flux type for example is a
physical quantity not a data model field hence UCD is used.  The data
model field used to identify the flux type does have a UType, i.e.
Char.FluxAxis.Ucd.

Anyway I thought this was still merely a REC, at least in the SSA query
response.  Where in the spec does it say that this is mandatory?

> Moreover I as I have insist many time that XML schema referenced should 
> really be accessible to see if it's compliant with the text
> xmlns:ssa="http://www.ivoa.net/xml/DalSsap/v1.0" is not available

The xmlns usage in data models currently is not actually used as a
schema.  A data model is an abstraction, not an XML document (except
maybe for an XML serialization of an instance), hence cannot be defined
by an XML schema.  What we really need is a formal data model
definition, which is a topic for another discussion.  Meanwhile it
should not be an error of the xmlns is not pointing to a real document.
The string still identifies the data model used and its version.  It was
put in essentially as a placeholder until we have a better mechanism for
this (just happens to be taking a while :-) ).

 	- Doug


> regards
> Pierre
>
> -- 
> -------------------------------------------------------------------------
>                           Pierre Le Sidaner
>                        Observatoire de Paris
>
> Division Informatique de l'Observatoire
> Observatoire Virtuel 01 40 51 20 89
> 61, avenue de l'Observatoire 75014 Paris
>
> mailto:pierre.lesidaner at obspm.fr
> http://vo-web.obspm.fr
>
> --------------------------------------------------------------------------
>