How to Build a Business Rules Engine

This shows how the rules engine framework built in the previous chapter can

easily be adapted for new rule types, and how the interface for one rule type can

resemble that for another.

Rather than go through all the program logic associated with the Valid Datatypes

for Screen Fields rule type, the relevant objects in the sample application are listed in

Table 16.1. The reader can use these to examine the details of the implementation.

This new rule type has not required the introduction of any fundamental new

components into the rules engine, but has been implemented creating components

based on marginal extensions to the rules engine. However, the next rule type will

require fundamental new rules engine components and an appreciation of new con-