Re: [rules-users] determining what field changed

Not really. Without modifying the objects you could do this outside the rules using a WorkingMemoryEventListener, which has objectInserted() and objectUpdated() methods. Event if you can modify the DataObject to add an "I'm a new object" flag, and set it immediately on insertion, then you could do differentiate with two rules: rule "identify new DATAOBJECT" when do : DataObject(n00b == true); then do.setN00b(false); update(do); System.err.println("DataObject assertion detected: " + do); end rule "identify modified DATAOBJECT" when do : DataObject(n00b == false); then System.err.println("DataObject modification detected: " + do); end Which would still catch a spurious modification notification on assert! At that point the semi-risky alternative is to not call update() in the "identify new DATAOBJECT" rule action. That way, the "identify modified DATAOBJECT" is not immediately activated, but it would be activated the next time update() is called on the object. I say semi-risky because it's not often a good idea to put a WM object into a state that the rete is not aware of, but in this case it would do what you want. --- On Wed, 9/16/09, Chris Richmond <crichmond(a)referentia.com&gt; wrote: