Re: [rules-users] need design suggestion

Wolfgang, thanks much. Helps me understand what's going on under the hood a little better. I'm having a similar issue with the next higher container. I have say, PathElements which contain a collection of Ports. Same problem as before - if one Port goes down then the PathElement goes down. I can't seem to express it properly in DRL The only thing that comes to me is: rule "pe down" when // pe is active $pe : PathElement(state == State.UP ) // and any one of the ports are down Port ( state == State.DOWN ) from $pe.ports then System.out.println(" setting pe down" + $pe ); modify($pe) { setState( State.DOWN); } end However, like my other naive attempts, it is not firing after the Notification is inserted into WM. I tried many variations using a 'collect' clause, etc to no avail. Any additional insight would be greatly appreciated. BTW, once i get a handle on the one-to-many associations I promise I'll stop :-) On Mon, Apr 2, 2012 at 11:47 PM, Wolfgang Laun <wolfgang.laun(a)gmail.com&gt;wrote: > See inline. > > On 02/04/2012, Joe Zendle <jzendle(a)zentechinc.net&gt; wrote: > > > > > > Here are my rules: > > > > rule "card going down" > > when > // There is a Card in state UP and... > > $card : Card($name : name , state == State.UP) > // a matching notification to DOWN > > $notif : Notification( id == $name, type == > NotificationType.CARD , > > state == State.DOWN ) > > then > > System.out.println(" got notification for card down " + $card ); > > modify($card) { > > setState(State.DOWN); > > } > > retract($notif); > > end > > > > // is the following rule correct?? > > No. > > > > > rule "port going down" > > when > > // There is a Port in State UP and... > > > $port : Port($name : name , state == State.UP, $card : card) > // ...take its Card and if this is DOWN > > > Card ( state == State.DOWN) from $card > > then > > System.out.println(" port down because card is down port: " + > $port + > > " card: " + $card ); > > modify($port) { > > setState(State.DOWN); > > } > > The difference between these two rules is that the first one is triggered > by > a change in WM - the emergence of a matching Notification. The second, > however, is evaluated when the Port enters WM, presumably with its > Card in working order. Subsequently, Port doesn't change and so evaluation > is never retried. > > > Two correct versions: > > when > $card : Card( state == State.DOWN ) > $port : Port($name : name , state == State.UP, card == $card) > then > > when > $port : Port($name : name , state == State.UP, $card: card ) > Card( this == $card, state == State.DOWN ) > then > > Or, assuming that Port must follow Card, for going UP and DOWN: > > when > $card : Card( $stateCard: state ) > $port : Port($name : name , state != $stateCard, card == $card) > then > modify($port) { > setState($stateCard) > } > > > > > > end > > > > Here is the test case in a nutshell: > > > > Port port1 = new Port(); > > Port port2 = new Port(); > > port1.setName("port1"); > > port2.setName("port2"); > > > > Card card1 = new Card(); > > card1.setName("port1 card1") > > port1.setCard(card1); > > // stateful session > > ksession.insert(port1); > > ksession.insert(port2); > > ksession.insert(card1); > > > > System.out.println(" firing rules"); > > new Thread(new Runnable() { > > public void run() { > > ksession.fireUntilHalt(); > > } > > }).start(); > > > > System.out.println("*** injecting notification down"); > > Notification notif = new Notification(); > > notif.setType(NotificationType.CARD); > > notif.setState(State.DOWN); > > notif.setId("port1 card1"); > > FactHandle notifHandle = ksession.insert(notif); > > > > > > ksession.halt(); > > ksession.dispose() > > > > > > I would expect the card down notification to cause the port to do down > > by > > the second rule above but it does not fire. > > > > Here is output > > > > card1: Card [state=UP, name=port1 card1, > > ne=org.plugtree.examples.model.NE@1e2670b] > > OBJECT ASSERTED value:Port [state=UP, name=port1, card=Card [state=UP, > > name=port1 card1, ne=org.plugtree.examples.model.NE@1e2670b]] factId: 1 > > OBJECT ASSERTED value:Port [state=UP, name=port2, card=Card [state=UP, > > name=port1 card1, ne=org.plugtree.examples.model.NE@1e2670b]] factId: 3 > > OBJECT ASSERTED value:Card [state=UP, name=port1 card1, > > ne=org.plugtree.examples.model.NE@1e2670b] factId: 5 > > firing rules > > 3 > > *** injecting notification down > > ACTIVATION CREATED rule:card going down activationId:card going down [6, > 5] > > declarations: $name=port1 card1(5); > > $notif=org.plugtree.examples.model.Notification@4a9a7d(6); $card=Card > > [state=UP, name=port1 card1, ne=org.plugtree.examples.model.NE@1e2670b > ](5) > > OBJECT ASSERTED > value:org.plugtree.examples.model.Notification@4a9a7dfactId: > > 6 > > BEFORE ACTIVATION FIRED rule:card going down activationId:card going > > down > > [6, 5] declarations: $name=port1 card1(5); > > $notif=org.plugtree.examples.model.Notification@4a9a7d(6); $card=Card > > [state=UP, name=port1 card1, ne=org.plugtree.examples.model.NE@1e2670b > ](5) > > got notification for card down Card [state=UP, name=port1 card1, > > ne=org.plugtree.examples.model.NE@1e2670b] > > OBJECT MODIFIED value:Card [state=DOWN, name=port1 card1, > > ne=org.plugtree.examples.model.NE@1e2670b] factId: 5 > > OBJECT RETRACTED > > value:org.plugtree.examples.model.Notification@4a9a7dfactId: 6 > > AFTER ACTIVATION FIRED rule:card going down activationId:card going down > > [-1, 5] declarations: $name=port1 card1(5); $card=Card [state=DOWN, > > name=port1 card1, ne=org.plugtree.examples.model.NE@1e2670b](5) > > > > > > > > Is the second rule written incorrectly? or do i have a gap in my > > expectations of how the engine should work (or both) > > > > Thanks in advance, > > > > Joe. > > > _______________________________________________ > rules-users mailing list > rules-users(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/rules-users >