[rules-users] rules for promotional offers
Sandeep Bandela
gibsosmat at gmail.com
Fri Sep 9 03:58:14 EDT 2011
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 at 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 at gmail.com>
>
>> 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 at gmail.com>
>>
>>> 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 at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
>>>
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
>
> --
> Regards,
> Sandeep Bandela.
>
>
--
Regards,
Sandeep Bandela.
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