Bob,

There is a misapplication of terminology in CodeBook. The item called a bizobj in CodeBook is not a business logic tier in the N-Tier design concept. It is an interface object. This can cause some confusion, in CodeBook it is the data behavior object that is what is commonly referred to as a business logic object in N-Tier design. The BizObj in CodeBokk is part of the user interface tier.

The data behavior object in CodeBook could be implemented as an activex server class and thereby be useful to applciations that are not written in Visual Foxpro, however the BizObj wouldn't work in that scenario because it contains interface objects that might not work in Excel, Word, or VB.

Keep in mind that the entire reason for N-Tier is to provide a system design that separates the user interface from the business rules and the database.

There are many things that are quite easy to do in VFP that become difficult when an N-Tier design is being used. If the requirement is to have multiple divergent front end applications developed in different languages or applications to access the same data and consistently enforce the business rules, then N_Tier is the way to go despite the limitations you may encounter.

However, if you are developing an application that will manage its own data and that data is not used in any other application (other than being read) then N-Tier is overkill and will add to the difficulty of creating the VFP application.