> At: https://sourceforge.net/p/roundup/mailman/message/34268641/

> is a discussion of computed properties for a class.

I  think  this  is very interesting issue. I think we must discuss a
design and future direction of roundup-tracker.

There are my raw thoughts.
 I  think that a ReadOnly  properties is more suitable to roundup-tracker
 conception  than  Computed. Firstly it can be typified and then
 used in template as usual.
 The example of external address book will look like:

user = Class(db, "user",
                ...
                phone=ROString("getPhoneFromLdap")
                ...
then:

  def getPhoneFromLdap(MyUser):
         return lookupPhoneGivenUser(Myuser['username'])