12 Oracle Business Rules

This chapter describes issues associated with Oracle Business Rules. It includes the following topics:

• Section 12.1, "Standalone OC4J Rule Author Installation"

• Section 12.2, "RL serviceDateValidation Error: Fact Class Should Be Declared Earlier"

12.1 Standalone OC4J Rule Author Installation

To install Rule Author in a Standalone OC4J, do the following:

1. Deploy Rule Author EAR, found in /Disk2/rules/webapps/ruleauthor_s.ear.

2. Create a security group "rule-administrators".

3. Create a Rule Author user, for example, ruleadmin, and add this user to the "rule-administrators" group.

4. Copy the "rules" directory from an installation of Oracle Application Server into the ORACLE_HOME of the Standalone OC4J install.

5. Stop and restart OC4J.

12.2 RL serviceDateValidation Error: Fact Class Should Be Declared Earlier

In certain cases, you can receive the following RL generation error:

"Fact class should be declared earlier ...".

For example, with the following generated RL for a data model:

ruleset DM {
 function CreateDataAndTestRules()
 {
 servOrders.ServiceOrderTypeImpl sot = new
servOrders.ServiceOrderTypeImpl();
.
.
.

This causes the implemented Impl class to be autofactclassed before the Type is factclassed. When the Type is then referred to in the rules, the following error is thrown:

ClassName: A syntax error is found. Error:fact class should be declared earlier at line 5 column 3 in serviceDateValidation

To fix this problem:

Classes with complex type hierarchies, for example they both extends a class and implements an interface must have classes referenced in a particular order. If the classes are not referenced in the correct order, then the rules engine cannot correctly determine the class hierarchy.

There are two ways to fix this problem:

• Check "supports XPath" for the ServiceOrderType class; this introduces a slight performance cost.

• Change the code in the CreateDataAndTestRules function. For example, change the instance creation to:

  servOrders.ServiceOrderType sot = new servOrders.ServiceOrderTypeImpl();
  

  This parses in the right order such that the superclass is created before the implementing class.