[plt-scheme] Snooze and application-level validation before persisting

We use the check library, which is part of Unlib.  Code is here:

  http://planet.plt-scheme.org/package-source/untyped/unlib.plt/3/8/check/check.ss

but it appears we haven't documented it, which is a bit of an
oversight.  Checks are attached to the appropriate pipelines (see
http://planet.plt-scheme.org/package-source/untyped/snooze.plt/2/2/planet-docs/snooze/persistent-struct.html)

More recent (unreleased) versions of Snooze make this process a bit simpler.

HTH,
Noel

On Fri, Nov 28, 2008 at 8:25 PM, Peter Michaux <petermichaux at gmail.com> wrote:
> I've been looking at the Snooze documentation
>
> http://planet.plt-scheme.org/package-source/untyped/snooze.plt/2/2/planet-docs/snooze/index.html
>
> I don't see anything about validating data before attempting to
> persist it to the database. I'm curious about how a programmer using
> Snooze would go about validating in the application. If there is
> invalid data, how does the model layer then either throw errors or
> return an errors object rather than attempting to persist the data.
>
> I'm thinking of a web application where the errors then need to be
> displayed to the user in an HTML form but this is not really a
> web-specific issue.
>
> Thanks,
> Peter