Progress

[Doug Tody]

On Mon, 23 Feb 2009, Francois Ochsenbein wrote:

> 1. About VOTable INFO (section 2.9.1) as mentionned before (end
>   of last year), plain text will not be allowed directly within
>   the INFO tag in VOTable1.2, but within a DESCRIPTION sub-element
>   e.g.
>   <INFO name="QUERY_STATUS" value="OK">
>    <DESCRIPTION>Successful query</DESCRIPTION>
>   </INFO>
>   (the textual comment is not essential in this example anyway :-)

The problem here is that V1.2 introduces a change to the way an
INFO is represented, which is not backwards compatible (all the DAL
interfaces will be affected by this).

There may be a simple solution however.  VOTable is versioned,
and defines a table model which is distinct from the serialization.
Hence VOTable 1.1 and 1.2 may provide the same logical INFO construct,
but different serializations, with the text appearing in different
places in the XML.  The TAP spec can thus merely refer to how INFO is
used in TAP, and if an actual XML snippet is provided as an example
note the version of VOTable this refers to (and also warn that this
construct is different in 1.1 and 1.2).

Hence TAP could require VOTable 1.1 or later, and either will work
provided the INFO construct works the same way in VOTable libraries
such as SAVOT.  To actually use VOTable 1.2 however will require that
both the client and server support this version.  Requiring that
only 1.2 would seem to be a bit strong if we do not yet even have
support for this new version in our VOTable libraries.  This should
be considered only if we must have features present only in 1.2.
My preference would be to require 1.1 or later if possible, and
gradually migrate to 1.2 as it becomes more widely supported.

 	- Doug