Re: [rules-users] rules for promotional offers

The result of the collect CE is changed due to the modify. You have to copy the list and use the copy in the loop. -W 2011/9/9 Sandeep Bandela <gibsosmat(a)gmail.com&gt;: > 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 > >>>> 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 > > _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users