On Jun 8, 2004, at 2:40 AM, Henrik Martensson wrote:
>
> "Validating" does not mean "breaking". It is the other way around.
> Validation is one form of error checking. It is when you don't check
> for
> errors that you end up with brittle software. Worse, you can end up
> with
> software that produces insane results without notifying anyone. This
> can
> be a killer, literally.
>
A couple of others answered this, I'd just add one more point: real
business-level validation checks a lot more than syntax. It's not
enough that a name and address field are filled in, that usually has to
unambiguously match a known customer. It's not enough that a date is
in the format specified by the schema, it has to be in an appropriate
timeframe (usually the recent past or the recent future). Given that
you have to validate all that stuff anyway, and that you have tools
such as XPath to extract the needed information from a more general
context rather than a rigid syntax, lots of people find that the
exercise of defining, agreeing to, and validating against a
syntax-level schema doesn't add enough benefit to justify the cost.
