[web2py] Catch and replace vars

[AsmanCom]

Hi,

i want to do a simple task:

def function_1():
    var_field_1=request.vars.field_1
    if var_field_1:
        return var_field_1


db.define_table('table_1',
                       Field('field_1','string' ),
                       Field('field_2', default=function_1)
                       )

db.table_1.field_1.default='Autogenerated'
db.table_1.field_2.default='Autogenerated'


I want to catch default vars from field 1 and insert them in field_2
instead.
Is this possible?


###becomes interesting when combined, with IS_IN_DB and the
get_or_create function###