[rules-users] Validation flow - defer expression evaluation

Hi, I was wondering which is the proper way to do sanity checks (not null etc...) on a fact before starting the actual business rules. I have created a a ruleflow with a validation node (VALRFG) and a business rule node (BRRFG) to determine execution order. If in the validation node a not null constraint is violated, the session is aborted (drools.halt()). Problem with this approach is that assertions defined in rules of the ruleflow-group "BRRFG" are validated before the validation rules execute. The engine throws exception at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:298) at org.drools.reteoo.AlphaNode.assertObject(AlphaNode.java:130). ... at org.drools.base.mvel.MVELPredicateExpression.evaluate(MVELPredicateExpression.java:101) at org.drools.rule.PredicateConstraint.isAllowed(PredicateConstraint.java:291) How can I make sure that the validation rules are executed before the mvel expressions in the business rules are being evaluated? Thanks for feedback, -- View this message in context: http://drools.46999.n3.nabble.com/Validation-flow-defer-expression-evalua... Sent from the Drools: User forum mailing list archive at Nabble.com.