New Web Service at CDS

[Mark Taylor]

> A UCD resolver is now available as a Web Service at CDS. 
> See http://cdsweb.u-strasbg.fr/cdsws.gml for more details and an example 
> of use. 

Another web service which would be useful is provision of a list of all
the currently-defined UCDs (with descriptions). 

<a href="http://www.starlink.ac.uk/topcat/">TOPCAT</a>, 
a table-editing tool I am developing, has cause to ask the user to 
select a UCD with which to label a column from a list of all known UCDs.
I currently construct this list by screen-scraping the page at
<a href="http://vizier.u-strasbg.fr/viz-bin/UCDs">http://vizier.u-strasbg.fr/viz-bin/UCDs</a>,
which is downloaded and stored at build time.
It could be good however to be able to retrieve and parse such a list
at run time, so that recently-defined UCDs are available even when
an old version of the tool is being used.

I'm not a SOAP expert so I'm not sure what would be the best way to
supply the result of such a query, but I guess it could be a simple
XML document, perhaps reflecting the hierarchical nature of the list,
something like:

   <ucd id="AT" description="Atomic Data">
     <ucd id="AT_COLL" description="Atomic Collisional Quantities">
       <ucd id="AT_COLL_EXCIT-RATE" description="Collisional Excitation Rate"/>
       <ucd id="AT_COLL_STRENGTH" description="Collisional Strength"/>
     </ucd>
     <ucd id="AT_CONFIG" description="Electronic Configuration"/>
       ...
     </ucd>
   </ucd>
   <ucd id="CLASS" description="Various Classification Descriptors"/>
     ...

you get the idea.  Even something as simple as a flat tab-separated list
would be OK though, as long as the endpoint and format could be 
relied upon.

Mark

-- 
Mark Taylor    Starlink Programmer    Physics,  Bristol University, UK
m.b.taylor at bris.ac.uk  0117 928 8776  http://www.star.bris.ac.uk/~mbt/