SIAv2: FORMAT?

[François Bonnarel]

Hi Alberto, all

I understand the concern, but the logic of SIAP 2.0 (I instit on .0) is 
that it is not forcing outputs but only selecting.**

SO interprtaion 1 ) is correct. If you ask FORMAt=jpeg and everything is 
in application/fits you select .... nothing.

Allowing virtual data in SIAP 2.1 (which I hope tio happen, ASAP) will 
change the behavior of FORMAT to force the output to be be jpeg.

My 2 cents
Cheers
François

Le 11/03/2019 à 18:56, alberto micol a écrit :
>
>
>       Dear DAL,
>
> I have a question regarding the FORMAT input parameter described in 
> SIAv2.0:
>
>
>       2.1.17 FORMAT
>
> The FORMAT parameter specifies response format(s)  (the access_format 
> column from the ObsCore [7] data model). This column describes the 
> format of the response from the access_url (see 3.1.3 
> <http://www.ivoa.net/documents/SIA/20151223/REC-SIA-2.0-20151223.html#bkmRefHeading200962138146524>) 
> so the values could be data file types (e.g. application/fits) or they 
> could be the DataLink [8] MIME type.
>
> It is unclear to me how to read that.
> I have two possibilities in mind:
>
> 1) The FORMAT input param is used to add a constraint onto the 
> access_format, e.g.:
>
>   ...&FORMAT=application/fits
>
>   gets translated into a constraint like:
>
>   SELECT ... WHERE access_format = 'application/fits
>
> but that does not seem to have much sense, as some data providers 
> might have decided that access_format in the ObsCore table is always 
> the datalink mime type, delegating and delaying the specification of 
> the correct mime type to datalink.
> In such case, the result of the above query will always be an empty set.
>
> 2) a different way of reading 2.1.17 is that FORMAT determines which 
> access_format will be used in output, that is...
>
> if ...&FORMAT=application/fits
>
> then the returned votable will contain:
>
> access_format=application/fits
> access_url=the URL to directly download the FITS file (and not a datalink)
>
> while if FORMAT=application/x-votable+xml;content=datalink
>
> then the access_format will 
> be "application/x-votable+xml;content=datalink”
> and the access_url will return the datalink link.
>
>
> Could you please help me understand the 2.1.17 specification?
> I would go for interpretation (2) above, but I see that some of you 
> have implemented (1) instead...
>
> Many thanks in advance,
> Alberto
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.ivoa.net/pipermail/dal/attachments/20190311/15f3bb24/attachment-0001.html>