RE: When To Use Schemas (Was RE: infinite depth to namespaces)

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

Validate a field on input?  So I load a really big schema to validate 
a field on losing focus?  Seems inefficient if the form has been scoped and 
I have an external set of validation functions included.  I could 
break it up into mini-schemas, but I have to manage those, or 
I could generate the schema on the fly using server code, but 
is just pushing code to the other end of the pipe (has some 
advantages).   IOW, performance still counts.

Yes, centralization and diversity can be at odds. But any 
one out here that is building custom one off apps is in a 
different business from those of us who build complex 
agency applications.   Sure, there can be a set of data 
rules and we have those down cold in our market.  But 
each agency and each state and each country gets to 
futz with them (real problems with m12n).  We never quite 
get into the turnkey game supporting enterprise data. 
It sounds like a good idea, but doesn't pan out.   
One can seek to keep onsite implementation and 
customization costs from making a tier 2 system cost 
like a tier 1 system and stay out of the tier 3 systems 
altogether.  We scale technology to the market not the 
other way around.  XML is supposed to help us do that 
but XML still requires a force of standardization, so 
those who think the w3c should be turned into a group 
of anti-standard heads probably isn't in the tier 1 or 
2 marketplace.

As one who reads a lot of RFPs, the only group I'd like 
to nail to the masthead is the proposal consultant who 
actually never had to build a system, or hasn't 
built one for twenty five years, or built the 
last one as a web application and doesn't understand 
the problems of non-Intenet mission critical apps 
that may or may not have web interfaces.

Len 
http://www.mp3.com/LenBullard

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h


-----Original Message-----
From: Jeff Lowery [mailto:jlowery@scenicsoft.com]

The tricky part is the management of divergent concerns. Pretending that you
can meet all concerns with one set of rules is not going to get one very
far.

> Because a form is usually 
> is a subset of all of the database fields, I can group 
> all the validations into a single onSubmit function. 
> So far, I don't need the schema.

Get your schema to enforce rules on your input fields. Multi-purpose it. 

> 
> So when do I need it?  Obviously, it is a nice contract.

And enforceable in a variety of ways. There's still the extra stuff that's
not handled by the schema, but the schema can be loosely bound to what is
extra.