An STC "when" and "where" example

[Alasdair Allan]

Josh Bloom wrote:
> Alasdair Allan wrote:
>> Just because the majority of the VO was written in Java doesn't mean 
>> the whole world uses Java. VOEvent is designed to go outside the  
>> carefully crafted VO infrastructure. People who have never heard of 
>> the VO might be interested, for the first time, in some of the stuff 
>> we're doing here. The buy-in for VOEvent has to be small, minimal.
>
> When deciding how tiny a valid VOEvent is allowed to be, I think we 
> need to be reminded about who will use the messaging system and, 
> perhaps more important, who will get worthwhile science out of the 
> system. Yes, Joe-I've-Got-A-10cm-Scope-In-My-Yard will be interested 
> in followup, and could harvest targets off a web-based front end at a 
> VOEvent
> server....but I doubt he will have much to contribute to warrant such 
> a simplistic XML message (these messages are not suppose to be parsed 
> by humans right?!).

That isn't the point at all! I'm not arguing that it should be human 
readable for heaven's sake...

> The litmus test should be where these such projects could devote ~< 2 
> coder-weeks to writing an elegant hook into their system. We all could 
> provide a simple backend client API in whatever language we want and 
> they can do the dirty work turning/convert their own internal 
> transient language into VOEvent-speak.

If you seriously think you could implement a factory and parser toolkit 
for something as complex as STC in 2 weeks that actually did something 
useful with the result then I'd be very surprised. To do anything 
useful a parser for something as complex as STC doesn't just read the 
message, it must have the ability to convert the message contents in a 
locally useful information. For instance converting between different 
co-ordinate and time frames. Ditto for a generic factory toolkit to 
generate the serialised XML, such a factory has to have the ability to 
digest a wide range of co-ordinate frames and successfully parse and 
convert them to a serialisable STC instance. That isn't a trivial task.

Al.