[Esip-discovery] Datacasting custom elements proposal

Mattmann, Chris A (388J) chris.a.mattmann at jpl.nasa.gov
Fri Mar 18 09:41:22 EDT 2011

Hi Hook,

On Mar 17, 2011, at 11:34 PM, Hua, Hook (388C) wrote:

> Hi Sean and Chris,
> (1) I recall we had a similar discussion back in the Federated OpenSearch Cluster about whether we should assume that the clients are namespace aware. There could be some readers that are badly written (e.g. not using formal XML parsers) and therefore not compliant. All we can do on the server side is to do the right thing and always use namespaces.


> (2) Sean, your points on custom tags could also be equally valid for OpenSearch and ServiceCasting responses as well. Your example custom tag for dataSource could also be a custom tag for the other Discovery responses.
> So should we generalize your proposal across the other Discovery services too? If so, then we probably shouldn't use a "datacasting" namespace as in:
> <datacasting:dataSource>foo</datacasting:dataSource>
> But for the sake of making progress, I could see the need to concentrate on one service type at a time. But then again, there are overlaps.

I'd say it might be good to consider some following research questions and to actually generate some #s behind them before getting far down any path. I've heard a lot of concern regarding collision. Does anyone know:

1. what the frequency % of collision is in at least some X use cases? IOW, how often does this happen? I have my own views on this BTW but I'd rather just see some real data points.
2. what are the top Y feed readers we're targeting? I would hope the answer is not Y = all of them. Downstream users and consumers can always think of ways to break "standards" and rather than design for those cases, I think resources and effort are best spent designing for the actual ones first (starting small then growing big).


Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: chris.a.mattmann at nasa.gov
WWW:   http://sunset.usc.edu/~mattmann/
Phone: +1 (818) 354-8810
Adjunct Assistant Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA

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