Re: [rules-users] Events - Determining the Fact Pattern

Thanks Mark, I tried to analyze (in the debugger) the RETE network, and to my understanding, it is not possible to map back from the RETE nodes to the rule pattern. in the example above the two Person patterns will share the same EntryPointNode and ObjectTypeNode, hence, there is no way to determine what was the original pattern. My use case, is to generate 'explanation' objects. These object will log for each successful rule firing the identifiers of the facts that produced this consequence. Later on, we want to enable providing explanations as: "we reached this conclusion because field (actual=2) < 4". So, in the explanation process we want to substitute the rule patterns with actual facts. When the rule patterns are of the same object-type, there is a possibility to confuse and to assign the wrong fact to the pattern. Hence, I wanted to determine and log what was the 'causing' pattern for each fact. I hope that my description is clear, BR, David Mark Proctor wrote: > > Mark Proctor wrote: >> David Boaz wrote: >>> Hi all, >>> >>> Is it possible to determine the Pattern that ‘produced’ a given Fact? >>> For >>> example, assuming we have the following rule and event handler: >>> >>> rule r1 >>> when p1:Person(...) >>> p2:Person(...) >>> then >>> ... >>> end >>> >>> protected class MyAgendaEventHandler extends >>> DefaultAgendaEventListener { >>> >>> @Override >>> public void >>> afterActivationFired(org.drools.event.rule.AfterActivationFiredEvent >>> event) >>> { >>> String ruleName = event.getActivation().getRule().getName(); >>> KnowledgeRuntime knowledgeRuntime = event.getKnowledgeRuntime(); >>> for (FactHandle factHandle : >>> event.getActivation().getFactHandles()) { >>> Object fact = knowledgeRuntime.getObject(factHandle); >>> Pattern pattern= ?; >>> } >>> } >>> } >>> >>> Is it possible to determine the Pattern that originate a Person >>> object? If >>> yes, how the pattern is identified? >>> >> no > We'll that's not exactly true, but it's not something an end user should > be doing. But the basic jist is the Activation wraps the AgendaItem if > you can get access to that it has a Tuple field, this references the > chaines of tuples that make up the row of data. you can iterate that > chain and each one has a handle field which you can match up with the > facthandle you are searching for. Further more each tuple references the > join node it was added via, which also has an index number, so you can > deduce the pattern from there. However I seriously doubt this is what > you want, and you probably need to think harder about your use case. > > Mark >>> Thanks, David >>> >> >> >> _______________________________________________ >> rules-users mailing list >> rules-users(a)lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/rules-users >> >> > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users > > -- View this message in context: http://www.nabble.com/Events---Determining-the-Fact-Pattern-tp22397570p22... Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users