Re: [Plastic-devs] VOQuest + PLASTIC

[Mark T. <m.b...@br...>]

On Tue, 9 May 2006, Inaki Ortiz wrote:

> Hi there guys
> 
> My name is Inaki Ortiz and I am currently developing VOQuest, a
> PROTOTYPE tool to query and access VO services implementing source
> catalog data model. The idea is to make use of several VO standards like
> ADQL and VOTable to interconnect services. Besides that, we aim to make
> use of PLASTIC to relegate the usage of existing functionalities to the
> top performers on each field, like Topcat and Aladin, for example. We do
> not intend to re-invent the wheel, and that's why I find PLASTIC a great
> idea and a pretty neat implementation. So congratulations to you all,
> first.
> 
> Now... some problems :-(
> 
> From VOQuest we can actually send a VOTable to Topcat through the 'load'
> message by just using one parameter. Nonetheless,the documentation
> states that two parameters are needed
> 
>        http://plastic.sourceforge.net/coremessages.html
> 
> On the other hand, Aladin supports the two parameters invocation. So at
> the end I have to hard-code the invocations based on which service
> VOQuest is calling to. I would like to get rid of it and call both
> services in the same way so I would like to ask if a quick patch on
> Topcat is possible and feasible. If not... is there any other
> alternative? Please be aware that VOQuest has the VOTables loaded into
> memory and, as we do not intend to have access to the end user's local
> file system, we can just make use of the 'load' message and not
> 'loadFromURL'.

Hallo Inaki,

clearly TOPCAT is in error here and I can make a change quickly.
The form of the message it supports was correct for an earlier
version of the /votable/load message and I failed to update it
when the definition was changed.  I'll let you have a (pre-release) 
fixed version later today, and hopefully make a new public release
with this and some other changes by the end of the week.

With hindsight I'd say that the way the change was made was suboptimal - 
if the parameter list change had been 

   (String votable) -> (String votable, String id)

rather than

   (String votable) -> (String id, String votable)

when the new parameter was introduced it would have given applications
a better chance of dealing with both old and new forms of the message
with the same code.  It's probably too late to change back for 
/votable/load, but we can maybe bear that in mind for future revisions.

I look forward to talking about VOQuest in Victoria.

Mark

-- 
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b...@br... +44-117-928-8776 http://www.star.bris.ac.uk/~mbt/