>> First an example of a business rule:
>>
>> A Level 1 manager has a maximum signature
>> authority of $10K.
>>
>>
>> An auto loan applicant, living in Ohio, is
>> underage if he/she is under 18 years of age.
>>
>> If a customer has no outstanding invoices,
>> then the customer is of preferred status.
>>
>
> I agree those are business rules and are best kept out of a schema.
>
> What's more difficult are rules like "Every branch of the bank has a branch
> manager" - that's on the borderline between structural rules and business
> rules.
I've often wondered where you draw the line - do you check everything
possible in the xsd, or only in the application, or both.
There doesn't seem to be a simple answer, but a rough guide is: if you
don't want "branch manager" to ever be null, check it in the schema.
If however, you want a nice error message instead of one mentioning
"invalid content" and "complex type" then let it through to the app.
--
Andrew Welch
http://andrewjwelch.com
Kernow: http://kernowforsaxon.sf.net/
