[rules-users] How to execute a rule only when a fact is retracted

[Davide Sottara]

Yet another option to experiment with: use a listener to feed back trigger
facts in the WM


        ksession.addEventListener( new WorkingMemoryEventListener() {
            public void objectInserted(ObjectInsertedEvent event) {}
            public void objectUpdated(ObjectUpdatedEvent event) {}
            public void objectRetracted(ObjectRetractedEvent event) {
                if( ... ) { ... ksession.insert() ... }
            }
        });

Actually, "closure callbacks" have already been discussed and will probably
be provided soon

Davide



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