Validation

I am using Keel 2.0 currently.  Is there support for the Struts validator still
baked into keels implementation of Struts?  Or is there something that is
taking its place.  I ask this because the validateField method on persistents
seem to only check for null, and then for a default value.  And so any other
validation seems to occur when the database might complain, which is too late
in many cases.  

-Nate