Methods to serialise - Re: [QUANTITY] doc consistency

[Martin Hill]

This is all implementation stuff not part of our data modelling.  The 
bit that does the serialisation is likely to be very different across 
languages; for example a java one might not be a method on the object at 
all, but reflection-based inspection of the classes.  A FORTRAN one 
might be a procedure in a 'class'/module, but in general serialisation 
works better (long term) from code 'outside' the object.

(BTW defining such methods binds our model to its representation which 
we ought to avoid - for example we would have to say that some objects 
take 'SQL statement' as a method, and some don't.  We also block anyone 
from adding their own serialisations without fiddling with the object 
model).

Let's work out the data model, then work out how it might be 
represented.  The programmers who write the libraries (me! me!) are the 
right ones to do the bit inbetween.

Having said that, it would be worth listing the forms we will expect to 
use to represent our data.  Presumably we start with:

  * XML/VOTable/table (ie the table form of VOTable)
  * XML/Marshallable (eg using Castor/Axis/WSDL2Java etc)
  * FITS/table (with VOTable header?)

I can't think how serialisation would work with SQL; it may be that bits 
of ADQL might be able to make use of it...

Pierre Didelon wrote:
> Hi,
> 
> Pierre Didelon wrote:
> 
> 
>> Another point concerning all the levels is related to serialisation. 
>> As you
>> outlined it, it is  a very important point and I feel that a 
>> corresponding
>> method would preferably included in the interface definition at each 
>> level.
>>
> 
> May I insists?
> It would be nice to materialise the serialization possibility
> of quantity by a method, appearing in clase Frame or BasicQuantity.
> Moreover it would be nice if this "serialize" method could have a 
> calling param
> to choose the output format, this one could perhaps be pure_xml, VOTable,
> ASCII, Fits, SQL Statements... or whatever needed or required, 
> incrementally,
> starting implementation of the most obvious one, which would be
> the default format, if the required one by user is unavailable
> Something like getSerialization(format: string): string
> 
> regards,
> pierre
> 
> 


-- 
Martin Hill
www.mchill.net
07901 55 24 66