SODA, half-client

[James.Dempsey at csiro.au]

Hi Mark,

The main reason is for the convenience of users. In the services I have set up I have inevitably been requested to provide friendly, unique, names for downloads. The extension is helpful for windows users where it is used to determine file launch actions. Also, consider this not in the context of doing a cutout now and using it, but rather in the context of coming back in a week and seeing dlget, dlget-1, dlget-2 etc and wondering which is which.

The name currently comes from the url, but you can specify the file name as part of the download stream header, which will split it from the url. I definitely agree that it is best not to force the url to carry the filename and extension.

Cheers,
James Dempsey

________________________________________
From: Mark Taylor <phmbt at bristol.ac.uk> on behalf of Mark Taylor <M.B.Taylor at bristol.ac.uk>
Sent: Thursday, 31 March 2016 9:14 PM
To: Dempsey, James (IM&T, Yarralumla)
Cc: msdemlei at ari.uni-heidelberg.de; dal at ivoa.net
Subject: RE: SODA, half-client

On Thu, 31 Mar 2016, James.Dempsey at csiro.au wrote:

> While no doubt outside the prototype UI, the downloaded file has a static name dlget. It would be useful if this had a fits extension and perhaps related back to the original image.

why?  My general position is that URLs should be treated as opaque,
and in particular relying on file extensions is a bad idea
(except on OSs where they are supposed to be significant, or maybe
as a hint in absence of other information).  In this case there
is a Content-Type: image/fits, which is where you should look.
But if there are good reasons to disagree with that, by all means
argue them.

Having said that: I tried using Markus's (nice) client with
SAOImage DS9 and SkyCat/GAIA as alternative image viewer SAMP clients.
Both failed, for reasons that I'm guessing are to do with the quite
ugly URL
(http://dc.zah.uni-heidelberg.de/califa/q2/dl/dlget?ID=ivo%3A%2F%2Forg.gavo.dc%2F~%3Fcalifa%2Fdatadr2%2FIC1528.V1200.rscube.fits&DEC=-7.097008036747518%20-7.089047402267772&RA=1.2644871315905835%201.2799343705069166&&&&&&&).
However, I've filed bug reports in both cases, since I'd see that
as a failure of the client not the service.

Mark

--
Mark Taylor   Astronomical Programmer   Physics, Bristol University, UK
m.b.taylor at bris.ac.uk +44-117-9288776  http://www.star.bris.ac.uk/~mbt/