9:21 p.m.
I have been reading through the documentation and trying some of the
tutorials and have a question about the no-loop attribute.
Not really relevant to the post, but I figured I would mention it, I have
been following this post and updating it to use the current version of
Drools. http://www.onjava.com/pub/a/onjava/2005/08/03/drools.html?page=7
I have written my rules as such:
package org.drools.examples
import org.drools.examples.StockOffer;
rule PriceBelow100
dialect "java"
when
s: StockOffer( stockPrice < 100 && recommendPurchase == null )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule NegativeStockPrice
dialect "java"
no-loop true
when
s: StockOffer( stockPrice < 0 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
rule DontBuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice < 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule BuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice > 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
My question is, why do I have to put no-loop on every rule (except for the
first). After the first time through the rules, it shouldn't be modifying to
where the rules would fire it again. Am I doing something wrong with how my
rules are written? My sample data is this:
package org.drools.examples;
import org.drools.examples.BusinessLayer;
import org.drools.examples.StockOffer;
import junit.framework.TestCase;
/*
* JUnit test for the business rules in the
* application.
*
* This also acts a 'simulator' for the business
* rules - allowing us to specify the inputs,
* examine the outputs and see if they match our
* expectations before letting the code loose in
* the real world.
*/
public class BusinessRuleTest extends TestCase {
/**
* Tests the purchase of a stock
*/
public void testStockBuy() throws Exception {
// Create a Stock with simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue(testOffer.getRecommendPurchase() != null);
assertTrue("YES".equals(testOffer.getRecommendPurchase()));
}
/**
* Tests the purchase of a stock makes sure the system will not accept
* negative numbers.
*/
public void testNegativeStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(-22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue("NO".equals(testOffer.getRecommendPurchase()));
}
/**
* Makes sure the system will buy stocks of XYZ corp only if it really
cheap
*/
public void testXYZStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOfferLow = new StockOffer();
StockOffer testOfferHigh = new StockOffer();
testOfferLow.setStockName("XYZ");
testOfferLow.setStockPrice(9);
testOfferLow.setStockQuantity(1000);
testOfferHigh.setStockName("XYZ");
testOfferHigh.setStockPrice(11);
testOfferHigh.setStockQuantity(1000);
// Run the rules on it and test
BusinessLayer.evaluateStockPurchase(testOfferLow);
assertTrue("YES".equals(testOfferLow.getRecommendPurchase()));
BusinessLayer.evaluateStockPurchase(testOfferHigh);
assertTrue("NO".equals(testOfferHigh.getRecommendPurchase()));
}
}
I can post up all the code if this isn't enough to answer the question.
Thanks!
10:17 a.m.
You need no-loop on the rules because of the call to "modify(s)" .
Modify changes the fact in working memory and the engine is
automatically notified of the changes at the end of the modify block.
After modify the same rule could hit again as the conditions are still
true.
The first rule doesn't need the no-loop it because of the check
"recommendPurchase == null"
Joe
From: rules-users-bounces(a)lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Bryan Hansen
Sent: Sunday, November 02, 2008 8:21 PM
To: rules-users(a)lists.jboss.org
Subject: [rules-users] no-loop usage question
I have been reading through the documentation and trying some of the
tutorials and have a question about the no-loop attribute.
Not really relevant to the post, but I figured I would mention it, I
have been following this post and updating it to use the current version
of Drools.
http://www.onjava.com/pub/a/onjava/2005/08/03/drools.html?page=7
I have written my rules as such:
package org.drools.examples
import org.drools.examples.StockOffer;
rule PriceBelow100
dialect "java"
when
s: StockOffer( stockPrice < 100 && recommendPurchase == null )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule NegativeStockPrice
dialect "java"
no-loop true
when
s: StockOffer( stockPrice < 0 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
rule DontBuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice < 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule BuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice > 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
My question is, why do I have to put no-loop on every rule (except for
the first). After the first time through the rules, it shouldn't be
modifying to where the rules would fire it again. Am I doing something
wrong with how my rules are written? My sample data is this:
package org.drools.examples;
import org.drools.examples.BusinessLayer;
import org.drools.examples.StockOffer;
import junit.framework.TestCase;
/*
* JUnit test for the business rules in the
* application.
*
* This also acts a 'simulator' for the business
* rules - allowing us to specify the inputs,
* examine the outputs and see if they match our
* expectations before letting the code loose in
* the real world.
*/
public class BusinessRuleTest extends TestCase {
/**
* Tests the purchase of a stock
*/
public void testStockBuy() throws Exception {
// Create a Stock with simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue(testOffer.getRecommendPurchase() != null);
assertTrue("YES".equals(testOffer.getRecommendPurchase()));
}
/**
* Tests the purchase of a stock makes sure the system will not
accept
* negative numbers.
*/
public void testNegativeStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(-22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue("NO".equals(testOffer.getRecommendPurchase()));
}
/**
* Makes sure the system will buy stocks of XYZ corp only if it
really cheap
*/
public void testXYZStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOfferLow = new StockOffer();
StockOffer testOfferHigh = new StockOffer();
testOfferLow.setStockName("XYZ");
testOfferLow.setStockPrice(9);
testOfferLow.setStockQuantity(1000);
testOfferHigh.setStockName("XYZ");
testOfferHigh.setStockPrice(11);
testOfferHigh.setStockQuantity(1000);
// Run the rules on it and test
BusinessLayer.evaluateStockPurchase(testOfferLow);
assertTrue("YES".equals(testOfferLow.getRecommendPurchase()));
BusinessLayer.evaluateStockPurchase(testOfferHigh);
assertTrue("NO".equals(testOfferHigh.getRecommendPurchase()));
}
}
I can post up all the code if this isn't enough to answer the question.
Thanks!
10:37 a.m.
I think I follow you now. If I was a little smarter with my conditional
statements to NOT keep assigning YES to something that is already set to YES
then it would probably eliminate the loop. In other words if I added more
checks like the ==null that you pointed out, I could (although I am not sure
that they are bad) remove the no-loop settings. Right?
Thanks,
Bryan
On Mon, Nov 3, 2008 at 9:17 AM, Joe White <Joe.White(a)recondotech.com> wrote:
You need no-loop on the rules because of the call to
"modify(s)" . Modify
changes the fact in working memory and the engine is automatically
notified of the changes at the end of the modify block. After modify the
same rule could hit again as the conditions are still true.
The first rule doesn't need the no-loop it because of the check
"recommendPurchase
== null"
Joe
*From:* rules-users-bounces(a)lists.jboss.org [mailto:
rules-users-bounces(a)lists.jboss.org] *On Behalf Of *Bryan Hansen
*Sent:* Sunday, November 02, 2008 8:21 PM
*To:* rules-users(a)lists.jboss.org
*Subject:* [rules-users] no-loop usage question
I have been reading through the documentation and trying some of the
tutorials and have a question about the no-loop attribute.
Not really relevant to the post, but I figured I would mention it, I have
been following this post and updating it to use the current version of
Drools. http://www.onjava.com/pub/a/onjava/2005/08/03/drools.html?page=7
I have written my rules as such:
package org.drools.examples
import org.drools.examples.StockOffer;
rule PriceBelow100
dialect "java"
when
s: StockOffer( stockPrice < 100 && recommendPurchase == null )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule NegativeStockPrice
dialect "java"
no-loop true
when
s: StockOffer( stockPrice < 0 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
rule DontBuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice < 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule BuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice > 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
My question is, why do I have to put no-loop on every rule (except for the
first). After the first time through the rules, it shouldn't be modifying to
where the rules would fire it again. Am I doing something wrong with how my
rules are written? My sample data is this:
package org.drools.examples;
import org.drools.examples.BusinessLayer;
import org.drools.examples.StockOffer;
import junit.framework.TestCase;
/*
* JUnit test for the business rules in the
* application.
*
* This also acts a 'simulator' for the business
* rules - allowing us to specify the inputs,
* examine the outputs and see if they match our
* expectations before letting the code loose in
* the real world.
*/
public class BusinessRuleTest extends TestCase {
/**
* Tests the purchase of a stock
*/
public void testStockBuy() throws Exception {
// Create a Stock with simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue(testOffer.getRecommendPurchase() != null);
assertTrue("YES".equals(testOffer.getRecommendPurchase()));
}
/**
* Tests the purchase of a stock makes sure the system will not accept
* negative numbers.
*/
public void testNegativeStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(-22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue("NO".equals(testOffer.getRecommendPurchase()));
}
/**
* Makes sure the system will buy stocks of XYZ corp only if it really
cheap
*/
public void testXYZStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOfferLow = new StockOffer();
StockOffer testOfferHigh = new StockOffer();
testOfferLow.setStockName("XYZ");
testOfferLow.setStockPrice(9);
testOfferLow.setStockQuantity(1000);
testOfferHigh.setStockName("XYZ");
testOfferHigh.setStockPrice(11);
testOfferHigh.setStockQuantity(1000);
// Run the rules on it and test
BusinessLayer.evaluateStockPurchase(testOfferLow);
assertTrue("YES".equals(testOfferLow.getRecommendPurchase()));
BusinessLayer.evaluateStockPurchase(testOfferHigh);
assertTrue("NO".equals(testOfferHigh.getRecommendPurchase()));
}
}
I can post up all the code if this isn't enough to answer the question.
Thanks!
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
11:46 a.m.
Correct.
From: rules-users-bounces(a)lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Bryan Hansen
Sent: Monday, November 03, 2008 9:37 AM
To: Rules Users List
Subject: Re: [rules-users] no-loop usage question
I think I follow you now. If I was a little smarter with my conditional
statements to NOT keep assigning YES to something that is already set to
YES then it would probably eliminate the loop. In other words if I added
more checks like the ==null that you pointed out, I could (although I am
not sure that they are bad) remove the no-loop settings. Right?
Thanks,
Bryan
On Mon, Nov 3, 2008 at 9:17 AM, Joe White <Joe.White(a)recondotech.com>
wrote:
You need no-loop on the rules because of the call to "modify(s)" .
Modify changes the fact in working memory and the engine is
automatically notified of the changes at the end of the modify block.
After modify the same rule could hit again as the conditions are still
true.
The first rule doesn't need the no-loop it because of the check
"recommendPurchase == null"
Joe
From: rules-users-bounces(a)lists.jboss.org
[mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Bryan Hansen
Sent: Sunday, November 02, 2008 8:21 PM
To: rules-users(a)lists.jboss.org
Subject: [rules-users] no-loop usage question
I have been reading through the documentation and trying some of the
tutorials and have a question about the no-loop attribute.
Not really relevant to the post, but I figured I would mention it, I
have been following this post and updating it to use the current version
of Drools.
http://www.onjava.com/pub/a/onjava/2005/08/03/drools.html?page=7
I have written my rules as such:
package org.drools.examples
import org.drools.examples.StockOffer;
rule PriceBelow100
dialect "java"
when
s: StockOffer( stockPrice < 100 && recommendPurchase == null )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule NegativeStockPrice
dialect "java"
no-loop true
when
s: StockOffer( stockPrice < 0 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
rule DontBuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice < 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.YES)
}
end
rule BuyXYZStock
dialect "java"
no-loop true
when
s: StockOffer(stockName == "XYZ" && stockPrice > 10 )
then
modify( s ) {
setRecommendPurchase(StockOffer.NO)
}
end
My question is, why do I have to put no-loop on every rule (except for
the first). After the first time through the rules, it shouldn't be
modifying to where the rules would fire it again. Am I doing something
wrong with how my rules are written? My sample data is this:
package org.drools.examples;
import org.drools.examples.BusinessLayer;
import org.drools.examples.StockOffer;
import junit.framework.TestCase;
/*
* JUnit test for the business rules in the
* application.
*
* This also acts a 'simulator' for the business
* rules - allowing us to specify the inputs,
* examine the outputs and see if they match our
* expectations before letting the code loose in
* the real world.
*/
public class BusinessRuleTest extends TestCase {
/**
* Tests the purchase of a stock
*/
public void testStockBuy() throws Exception {
// Create a Stock with simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue(testOffer.getRecommendPurchase() != null);
assertTrue("YES".equals(testOffer.getRecommendPurchase()));
}
/**
* Tests the purchase of a stock makes sure the system will not
accept
* negative numbers.
*/
public void testNegativeStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOffer = new StockOffer();
testOffer.setStockName("MEGACORP");
testOffer.setStockPrice(-22);
testOffer.setStockQuantity(1000);
// Run the rules on it
BusinessLayer.evaluateStockPurchase(testOffer);
// Is it what we expected?
assertTrue("NO".equals(testOffer.getRecommendPurchase()));
}
/**
* Makes sure the system will buy stocks of XYZ corp only if it
really cheap
*/
public void testXYZStockBuy() throws Exception {
// Create a Stock with our simulated values
StockOffer testOfferLow = new StockOffer();
StockOffer testOfferHigh = new StockOffer();
testOfferLow.setStockName("XYZ");
testOfferLow.setStockPrice(9);
testOfferLow.setStockQuantity(1000);
testOfferHigh.setStockName("XYZ");
testOfferHigh.setStockPrice(11);
testOfferHigh.setStockQuantity(1000);
// Run the rules on it and test
BusinessLayer.evaluateStockPurchase(testOfferLow);
assertTrue("YES".equals(testOfferLow.getRecommendPurchase()));
BusinessLayer.evaluateStockPurchase(testOfferHigh);
assertTrue("NO".equals(testOfferHigh.getRecommendPurchase()));
}
}
I can post up all the code if this isn't enough to answer the question.
Thanks!
_______________________________________________
rules-users mailing list
rules-users(a)lists.jboss.org
https://lists.jboss.org/mailman/listinfo/rules-users
5864
days inactive
5864
days old
3 comments
2 participants
participants (2)
-
Bryan Hansen -
Joe White