RE: APIs, messaging

[Jeff Lowery <jlowery@scenicsoft.com>]

> >The data-centric butcher sends me a nice package of bacon. I 
> don't know what
> >part of the pig it came from, and I learn anything about 
> butchering, but I
> >got what I asked for, and no more. 
> 
> This butcher has reduced a pig, which is actually quite a 
> general-purpose kind of thing, to a dumbed-down package 
> hardwired to work in only one application of pigs. 

Yes. Why is this wrong? This is one reason why there are database 'views':
some DBA does all the querying for you. For a document sufficiently complex
with content that is only partially applicable to my domain, I can't see why
I can't have only the content that I can use. If there are other functional
dependencies on that content that I'm not aware of, then I don't understand
how merely giving the broader context really informs an automated system
that isn't aware of the dependencies. It would clue a human in (maybe), but
only break (at best) a functioning application.

> This reminds 
> me of reducing a complicated XML-encoded financial report to a 
> PDF and sending that along... neatly packaged all right, but 
> hardwired to one application.  

But the original XML-encoded financial report still exists, ready to be
consumed by other applications that will repurpose the content to their own
use! Translating any edits to the PDF back to the original XML document is
an exercise best left to the reader, of course. ;-) PDF is good for what PDF
is intended for (some would argue). It's not a very good format for general
data transport, however (but it gets abused that way, nonetheless).

> 
> I would hope that people who describe themselves as 
> "data-centric" have a little more respect for the stuff
> than this example would suggest. -Tim

Well, it was actually an analogy, not an example, and meant to be humorous
and not taken literally or absolutely. Certainly context is important (if I
understand your objection correctly) but in many cases it's implicitly
assumed in a closed system (the 'pig' system). Of course, there's the risk
of getting Canadian bacon instead of good ol' American fatty bacon, but that
termed a qualification failure or a context failure, depending on your POV.

And, just for the record, data-centric doesn't mean disregarding where data
came from; it does mean disregarding nonfunctionally-dependent data. On of
my qualifications for extracting the bacon *may* indicate where I want that
bacon extracted from. Ribs might be a better analogy (if I may dare): prime
rib? spare rib? short rib? Qualification or path? Could be either. Should
the client always be aware of where things are located (and what their
located with, in the off-chance that there's a content dependency there)? 

Anyway, you've been in this XML business about as long as anybody, Tim (so
I'm told).
That make me tremenously inclined to believe I'm the one wrongheaded here
(if either of us really are). I'm just having a little trouble fathoming
what exactly what it is I'm supposedly clueless about. It may take some
time...

-- Jeff

P.S.
If any data-centric people I've supposedly spoken for want to disown me,
feel free. <sniff>

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