IVOA LSST talk and JSON format for TAP

[Stelios Voutsinas]

Hi Brian and DAL.

Our approach matches your minimal version, and we have a client that runs a TAP request in JS, so I see a good case for JSON as an alternative option to VOTable. 
If we were to standardize, I would be cautious of over complicating it and having it lose the simplicity,which is the main reason why we are using it in the first place.
There probably are cases that I have not thought about however, so I'd be interested to see other implementations as well. 

So +1 from me for adding a note for this.

Cheers,
Stelios Voutsinas

________________________________________
From: dal-bounces at ivoa.net [dal-bounces at ivoa.net] on behalf of Van Klaveren, Brian N. [bvan at slac.stanford.edu]
Sent: Thursday, May 12, 2016 4:17 PM
To: dal at ivoa.net
Subject: IVOA LSST talk and JSON format for TAP

Apologies if this goes through multiple times... this internet is quite flaky.



Hi all,


If you are interested in my presentation about LSST and TAP/ADQL, i've uploaded the PDF to dropbox right now (until I can get it on the wiki):

https://www.dropbox.com/s/l89mpih9dmk2q3a/LSST_DAX_IVOA_Interop_May-2016.pdf?dl=0



Also, not sure if I'm going to make it to the meeting later, I need to take care of a few things for work as people in the US wake up and need a decent connection.


That said, if you end up talking about JSON, I was just going to post my example JSON response format for TAP and mention a few things about it:


https://gist.github.com/brianv0/07cf0acd83bde6f450a9


From my perspective, there's two use cases of a JSON response for TAP.


1. A 1:1 (or near to it) alternative to VOTable.

2. A simplified/minimal version intended to be very easy to use from Javascript.


For the first case, the output of something like that might look like the link above.


For the second case, a minimal representation might look like this:


{

  "columns": [

     {"name":"foo", "datatype":"int"},

     {"name":"bar", "datatype":"long"}

     {"name":"baz", "datatype":"double"}

  ],

 "data" : [

   [ 1, "1.12", 2.123]

   [ 2, "1.34", 2.345]

   [ 3, "1.56", 2.678]

  ]

}


This is extremely easy to deal with via javascript.


i.e:


var table = $(/* call TAP here via jquery */);

table.columns.forEach(function(i){ console.log(i.name)}); // log names

table.rows.forEach( doSomethingWIthRow );



So, if you end up talking about a JSON format, please consider these two potential use cases.


Thanks,

Brian​