Re: [rules-users] rules for promotional offers

Thanks wolfgang, for the info and that workaround. I think there is some off by one error in for loop, or may be some mistake that I didnt notice in my code. the following rule with 3 objects gives index out of bound error. I am attaching java & drl file (package com.example.drools.testing). I am using 5.2.0 final release. rule "Buy X units of Product A and Get Y units of Product B Free"     when         $itemsA : ArrayList( $a : size >= 2 ) from collect( CartItem( productId == "A", processed == false) )         $itemsB : ArrayList( $b : size >= 1 ) from collect( CartItem( productId == "B", processed == false) )         $m : RuleMessage()  then          $m.addMessage("sizes- A="+$a + " B="+$b);          int $x = 2;         int $y = 1;         $m.addMessage("sizes- X="+$x + " Y="+$y);         for(int i=0 ; i < $x ; i++){              CartItem $ci = (CartItem) $itemsA.get(i);              $m.addMessage( $ci.getId()+")Found item: "+$ci.getProductId());              modify((CartItem)$ci){                 setProcessed(true),                 setPromoItemDiscount(0D),                 setPromoId("2"),                 setBundleId(bundler.getId()),                 setAggregatorId(1)             };          };          for(int i=0 ; i < $y  ; i++){          CartItem $ci = (CartItem) $itemsB.get(i);              $m.addMessage( $ci.getId()+")Found item: "+$ci.getProductId());              modify((CartItem)$ci){                 setProcessed(true),                 setPromoItemDiscount($ci.getPrice()),                 setPromoId("2"),                 setBundleId(bundler.getId()),                 setAggregatorId(2)             };          };         bundler.increment(); end error Exception in thread "main" org.drools.runtime.rule.ConsequenceException: rule: Buy X units of Product A and Get Y units of Product B Free     at org.drools.runtime.rule.impl.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:39)     at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:916)     at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:845)     at org.drools.common.DefaultAgenda.fireAllRules(DefaultAgenda.java:1056)     at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:733)     at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:699)     at org.drools.impl.StatefulKnowledgeSessionImpl.fireAllRules(StatefulKnowledgeSessionImpl.java:218)     at com.example.drools.testing.Main.main(Main.java:52) Caused by: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1     at java.util.ArrayList.RangeCheck(ArrayList.java:547)     at java.util.ArrayList.get(ArrayList.java:322)     at com.example.drools.testing.Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.defaultConsequence(Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java:12)     at com.example.drools.testing.Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0DefaultConsequenceInvoker.evaluate(Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0DefaultConsequenceInvoker.java:44)     at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:906)     ... 6 more 2011/9/9 Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; > > If the declared type of productId and getProductId() is String, it should > be compared to a string literal. (A conversion might be made, but don't rely > on that.) > > You cannot access components of a global in RHS code using the simplified > notation (not unless you use "mvel" - but don't do that.) Here, all accesses > should be written the usual Java way, with getter and setter calls. > > The problem you have with modify(ci) is a bug (fixed for 5.3.0). As a > workaround,use > > modify( (CartItem)ci ){ ... } > > -W > > > 2011/9/9 Sandeep Bandela <gibsosmat(a)gmail.com&gt; >> >> some more info for the modify() problem, the CartItem is an interface and >> the implementation is CartItemImpl. if this info leads to some clues. >> >> >> On Fri, Sep 9, 2011 at 1:28 PM, Sandeep Bandela <gibsosmat(a)gmail.com&gt; >> wrote: >>> >>> Hi here is the same thing converted to mvl >>> >>> // this Bundler.java has integer member that keeps incrementing >>> global Bundler bundler >>> >>> rule "Apply 10% discount if you purchase 2 items" >>>     when >>>         $s1 : CartItem( productId == 219759, processed == false) >>>         $s2 : CartItem( this != $s1, productId == $s1.productId, >>> processed == false) >>>         $m : RuleMessage() >>>  then >>>         $m.addMessage("Found item1: " + $s1.getName() + " id: >>> "+$s1.getId()); >>>         $m.addMessage("Found item2: " + $s2.getName() + " id: >>> "+$s2.getId()); >>>         modify($s1){ >>>         setProcessed(true), >>>         setPromoItemDiscount($s1.getPrice() * 0.1), >>>         setPromoId("1"), >>>         setBundleId(bundler.getId()), >>>         setAggrigatorId(1) >>>         }; >>>         modify($s2){ >>>         setProcessed(true), >>>         setPromoItemDiscount($s2.getPrice() * 0.1), >>>         setPromoId("1"), >>>         setBundleId(bundler.getId()), >>>         setAggrigatorId(1) >>>         }; >>>         $m.addMessage("bundled ["+bundler.getId()+"] >>> "+$s1.getId()+","+$s2.getId()); >>>         bundler.increment(); >>> end >>> >>> the above rule dosent fire, but if I change the highlighter to >>> getProductId() == 219759, or use productId == "219759", may be this is some >>> edge case but it took long time for me to figure it out productId is String. >>> now consider the bundler.getId(), if I use bundler.id I get compilation >>> error. >>> >>> Rule Compilation error : [Rule name='Apply 10% discount if you purchase >>> 2 items'] >>> >>> com/example/promotions/promotionEngine/Rule_Apply_10__discount_if_you_purchase_2_items_0.java >>> (23:1592) : The field Bundler.id is not visible >>> 2011-09-09 13:18:39,863  INFO [STDOUT] - 2011-09-09 13:18:39,863  INFO >>> [PromotionsManager] - ksession initialized >>> 2011-09-09 13:18:39,863  INFO [STDOUT] - 2011-09-09 13:18:39,863  INFO >>> [PromotionsManager] - Exploding items and inserting cart >>> 2011-09-09 13:18:39,864  INFO [STDOUT] - 2011-09-09 13:18:39,863 ERROR >>> [CheckOutBasedUtilities] - Failed to apply promo offers >>> java.lang.RuntimeException: Unexpected global [bundler] >>>     at >>> org.drools.common.AbstractWorkingMemory.setGlobal(AbstractWorkingMemory.java:613) >>>     at >>> org.drools.impl.StatefulKnowledgeSessionImpl.setGlobal(StatefulKnowledgeSessionImpl.java:332) >>>     at >>> com.example.promotions.promotionEngine.PromotionsManager.applyOffers(PromotionsManager.java:154) >>>     at >>> com.example.promotions.promotionEngine.PromotionsManager.shuffleForOffers(PromotionsManager.java:61)` >>> >>> lastly my actual problem that I am looking for a solution lets say we >>> have "Buy X items of A and get Y Items of B". X=5 & Y=4 from the original >>> problem I want to template the rule and load the values of X,A,Y,B from >>> database or excel etc. if I use modify the error is as follows >>> >>> my rule >>> >>> >>> rule "Buy X units of Product A and Get Y units of Product B Free" >>>     when >>>         $itemsX : ArrayList( size == 2 ) from collect( CartItem( >>> getProductId() == 24257, !isProcessed())) >>>         $itemsY : ArrayList( size == 1) from collect(CartItem( >>> getProductId() == 24260, !isProcessed())) >>>         $m : RuleMessage() >>>  then >>>          for(Object item : $itemsX){ >>>              CartItem ci = (CartItem) item; >>>              $m.addMessage( ci.getId()+")Found item: "+ci.getItemId()+" >>> name: "+ci.getName()); >>>              modify(ci){ >>>                 setProcessed(true), >>>                 setPromoItemDiscount(0), >>>                 setPromoId("2"), >>>                 setBundleId(bundler.getId()), >>>                 setAggrigatorId(1) >>>             }; >>>          } >>>          for(Object item : $itemsY){ >>>          CartItem ci = (CartItem) item; >>>              $m.addMessage( ci.getId()+")Found item: "+ci.getItemId()+" >>> name: "+ci.getName()); >>>              modify(ci){ >>>                 setProcessed(true), >>>                 setPromoItemDiscount(ci.getPrice()), >>>                 setPromoId("2"), >>>                 setBundleId(bundler.getId()), >>>                 setAggrigatorId(2) >>>             }; >>>          } >>>         bundler.increment(); >>> end >>> >>> Rule Compilation error : [Rule name='Buy X units of Product A and Get Y >>> units of Product B Free'] >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (11:1236) : The method setProcessed(boolean) is undefined for the type >>> Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (12:1265) : The method setPromoItemDiscount(int) is undefined for the type >>> Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (13:1299) : The method setPromoId(String) is undefined for the type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (14:1325) : The method setBundleId(Integer) is undefined for the type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (15:1364) : The method setAggrigatorId(int) is undefined for the type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (22:1702) : The method setProcessed(boolean) is undefined for the type >>> Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (23:1731) : The method setPromoItemDiscount(Double) is undefined for the >>> type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (24:1777) : The method setPromoId(String) is undefined for the type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (25:1803) : The method setBundleId(Integer) is undefined for the type Object >>> >>> com/example/promotions/promotionEngine/Rule_Buy_X_units_of_Product_A_and_Get_Y_units_of_Product_B_Free_0.java >>> (26:1842) : The method setAggrigatorId(int) is undefined for the type Object >>> >>> Rule Compilation error : [Rule name='Apply 10% discount if you purchase >>> 2 items'] >>> >>> com/example/promotions/promotionEngine/Rule_Apply_10__discount_if_you_purchase_2_items_0.java >>> (23:1592) : The field Bundler.id is not visible >>> >>> >>> On Fri, Sep 9, 2011 at 12:40 PM, Sandeep Bandela <gibsosmat(a)gmail.com&gt; >>> wrote: >>>> >>>> Hi Wolfgang, >>>> This is what I did initially but for product > 2 I didnt find a generic >>>> way to do this. following is my first rule. I didnt use field names because >>>> it was giving error that member is not accessible. I will attach the errors >>>> of each case in a few mins. >>>> >>>> rule "Apply 10% discount if you purchase 2 items" >>>>     dialect "java" >>>>     when >>>>         $s1 : CartItem( getProductId() == 236061, !isProcessed()) >>>>         $s2 : CartItem( getProductId() == 236061, getId() != >>>> $s1.getId(), !isProcessed()) >>>>         $m : RuleMessage() >>>>  then >>>>         $m.addMessage("Found item1: " + $s1.getName() + " id: >>>> "+$s1.getId()); >>>>         $m.addMessage("Found item2: " + $s2.getName() + " id: >>>> "+$s2.getId()); >>>>         modify($s1){ >>>>         setProcessed(true), >>>>         setPromoItemDiscount($s1.getPrice() * 0.1), >>>>         setPromoId("1"), >>>>         setBundleId(bundler.getId()), >>>>         setAggrigatorId(1) >>>>         }; >>>>         modify($s2){ >>>>         setProcessed(true), >>>>         setPromoItemDiscount($s2.getPrice() * 0.1), >>>>         setPromoId("1"), >>>>         setBundleId(bundler.getId()), >>>>         setAggrigatorId(1) >>>>         }; >>>>         bundler.increment(); >>>> end >>>> >>>> 2011/9/9 Wolfgang Laun <wolfgang.laun(a)gmail.com&gt; >>>>> >>>>> Your rule exhibits procedural thinking. (For an aspiring rule >>>>> programmer his is typical teething troubles.) >>>>> >>>>> There's no need to collect all A's and B's in order to determine their >>>>> number being greater than one or two - this is achieved automatically by a >>>>> simple triple match rule. Consider >>>>> >>>>> rule "2A - 1B" >>>>> when >>>>>    $a1: CartItem( productId == "A", processed == false ) >>>>>    $a2: CartItem( this != $a1, productId == "A", processed == false ) >>>>>    $b: CartItem( productId == "B", processed == false ) >>>>> then >>>>>    modify( $a1 ){...} >>>>>    modify( $a2 ){...} >>>>>    modify( $b ){...} >>>>> end >>>>> >>>>> Note: >>>>> >>>>> The modify is essential. (When you say "doesn't work", always provide >>>>> details.) >>>>> Use the field name rather than the getter call - it improves >>>>> readability. >>>>> I'm not sure whether 5.2.0 final handles boolean fields correctly - >>>>> IIRC, there were some issues. It's possible that CartItem(..., !processed) >>>>> works. >>>>> >>>>> -W >>>>> >>>>> 2011/9/8 Sandeep Bandela <gibsosmat(a)gmail.com&gt; >>>>>> >>>>>> Hi, >>>>>> I am new to rules engine, after going through the examples shipped >>>>>> (shopping.drl, petstore.drl) >>>>>> I am trying to implement promotional discounting using drools 5.2.0 >>>>>> final, stateful session. assume cart has all the items that customer wants >>>>>> to buy, >>>>>> I am trying to bundle them together with the existing offers >>>>>> >>>>>> rule "Buy X units of Product A and Get Y units of Product B Free" >>>>>>     dialect "java" >>>>>> when >>>>>>     $itemsA : ArrayList( size >= 2) from collect( CartItem( >>>>>> getProductId() == "A", !isProcessed())) >>>>>>     $itemsB : ArrayList( size >= 1) from collect( CartItem( >>>>>> getProductId() == "B", !isProcessed())) >>>>>> then >>>>>>     // current scenario buy 2*A and get 1*B >>>>>>     int x = 2; >>>>>>     int y = 1; >>>>>>     for(int i=0 ; i < x ; i++){ >>>>>>         CartItem $ci = (CartItem) $itemsA.get(i); >>>>>>         // modify($ci){setProcessed(true) ... } dosent work >>>>>>         $ci.setProcessed(true); >>>>>>         $ci.setItemDiscount(0.0); >>>>>>         $ci.setBundleId(bundler.getId()); >>>>>>     } >>>>>> >>>>>>     for(int i=0 ; i < y  ; i++){ >>>>>>         CartItem $ci = (CartItem) $itemsB.get(i); >>>>>>         $ci.setProcessed(true); >>>>>>         $ci.setItemDiscount($ci.getPrice()); >>>>>>         $ci.setBundleId(bundler.getId()); >>>>>>     } >>>>>>     // global counter to identify bundled items >>>>>>     bundler.increment(); >>>>>> end >>>>>> >>>>>> the above rule calculates only for 1 set of offer i.e first 2*A & 1*B >>>>>> are considered, rest in the cart are not bundled. >>>>>> if customer buys 4*A + 2*B it dosent consider it. am I missing >>>>>> anything? is this the right way to do it? >>>>>> any feedback is appreciated. >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Regards, >>>>>> Sandeep Bandela. >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> 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 >>>>> >>>> >>>> >>>> >>>> -- >>>> Regards, >>>> Sandeep Bandela. >>>> >>> >>> >>> >>> -- >>> Regards, >>> Sandeep Bandela. >>> >> >> >> >> -- >> Regards, >> Sandeep Bandela. >> >> >> _______________________________________________ >> 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 > -- Regards, Sandeep Bandela. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users