[web2py] Counter based on fields being true or false.

[annet]

In db.py I have the following table:

db.define_table('function',
 
Field('company_id',db.company,default='',notnull=True,writable=False,readable=False),
    Field('home',type='boolean',default=True,writable=False),
    Field('logo',type='boolean',default=False),
    Field('tagline',type='boolean',default=False),
    Field('image',type='boolean',default=False),
    Field('text',type='boolean',default=False),
    Field('css',type='boolean',default=False),
    Field('customcss',type='boolean',default=False),
    Field('keywords',type='boolean',default=False),
    Field('counter',type='integer',default=1),
    migrate=False)


In a cms the administrator makes functions available to users by
(un)checking them. Now the counter should keep track of the number of
checked functions.

The cms function:

def functions():
    ....
    db.function.company_id.default=id
    form=crud.update(table=db.function,record=row,next=URL\
    (r=request,f='home',args='updated'),message=message)
    return dict(form=form)


Is there a validator available to update the counter or is this best
solved in JavaScript. If so, I hope one of you can provide me with an
example, because I don't know much about JavaScript.


Kind regards,

Annet.