Re: [rules-users] modify and update is not working in the rule file

I agree with Stephen, if you need an action (e.g. logging) when a constraint is violated, you are actually defining rules to handle the "negative" cases. Drools verifier will not help you here, since knowing whether a fact satisfied a constraint or not is a runtime problem and depends on the combination of data and rules, whereas verifier looks at rules alone. Could you please provide more details about your specific requirement? Do you just need to know when a condition fails? Or do you need a full analysis? I think we already discussed it: if you have a pattern with a number of conditions, the engine will stop evaluating a fact as soon as the first violation is encountered. Like in java, "&&" evaluation is terminated eagerly. (In this case, the "not" CE would help). Also consider this remark: when a constraint such as "field == value" is not satisfied, the engine *silently* stops propagating the fact along that branch of the RETE. So, there is no way to be notified of the failure of a constraint. The WorkingMemoryListener and the AgendaListener will report only events with a coarser granularity, so they won't help you. If you really really really ... really need it, you will have to tweak the engine. I could show you a few possible ways to do that, but I'm a bit reluctant... -- View this message in context: http://drools.46999.n3.nabble.com/modify-and-update-is-not-working-in-the... Sent from the Drools: User forum mailing list archive at Nabble.com.