Empty fields - dynamic

[Lance Norskog]

Is there a way to specify that a dynamic field cannot have an empty string?
With static fields, you can enforce this with 'required="true"
default="-1"'.
 
Is there any way to do enforce this in the shipped Solr 1.2?  One could
write a new custom analyzer that requires input. But is there anything
available out of the box?
 
Thanks,
 
Lance Norskog