[rules-users] "Exists" CE behaviour
Wolfgang Laun
wolfgang.laun at gmail.com
Mon Jul 13 07:20:41 EDT 2009
https://jira.jboss.org/jira/browse/JBRULES-2206 created.
Thanks for the code!
-W
On 7/13/09, Chivotario Martin <chivotario at gmail.com> wrote:
> Hi Wolfgang,
>
> I do not know if i can use the issue tracker to post this as an issue, as i
> don't know if i'm allowed to do so, and also if this is officially, really a
> bug or the expected behaviour :) .
>
> However i left a complete piece of code showing the behaviour i'm getting :
>
> RuleTester.java
>
> package org.drools.test;
>
> import org.drools.KnowledgeBase;
> import org.drools.KnowledgeBaseConfiguration;
> import org.drools.KnowledgeBaseFactory;
> import org.drools.RuleBaseConfiguration;
> import org.drools.builder.KnowledgeBuilder;
> import org.drools.builder.KnowledgeBuilderFactory;
> import org.drools.builder.ResourceType;
> import org.drools.io.ResourceFactory;
> import org.drools.runtime.StatefulKnowledgeSession;
>
> public class RuleTester {
>
> private static final int MAX_EVENTS = 5;
>
> public class Foo { }
>
> public void test() {
>
> KnowledgeBaseConfiguration config =
> KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
>
> ((RuleBaseConfiguration)config).setRuleBaseUpdateHandler(
> null );
> KnowledgeBase kbase =
> KnowledgeBaseFactory.newKnowledgeBase(config);
>
> StatefulKnowledgeSession session =
> kbase.newStatefulKnowledgeSession();
>
> for (int i=0; i<MAX_EVENTS; i++) {
> session.insert(new Foo());
> }
>
> for (int i=1; i<3; i++) {
> KnowledgeBuilder kbuilder =
> KnowledgeBuilderFactory.newKnowledgeBuilder();
> kbuilder.add(
> ResourceFactory.newClassPathResource( "test"+i+".drl" ),
> ResourceType.DRL);
>
> if( kbuilder.hasErrors() ) {
> System.out.println( kbuilder.getErrors() );
> return;
> }
>
> kbase.addKnowledgePackages(
> kbuilder.getKnowledgePackages() );
>
> int fireCount = session.fireAllRules();
>
> System.out.println("Test"+i+".drl , number of
> rules fired = "+fireCount);
>
> }
>
> session.dispose();
>
> }
>
> public static void main(String[] args) {
> RuleTester tester = new RuleTester();
> tester.test();
> }
>
> }
>
>
> test1.drl
>
> import org.drools.test.RuleTester.Foo;
>
> rule "notNotRule"
> when
> exists ( Foo() );
> then
> System.out.println("Rule fired...");
> end
>
> test2.drl
>
> import org.drools.test.RuleTester.Foo;
>
> rule "notNotRule"
> when
> not ( not ( Foo() ) );
> then
> System.out.println("Rule fired...");
> end
>
>
> Using Drools 5.0.1-Final , the expected output would be :
>
> > Test1.drl , number of rules fired = 0
> > Rule fired...
> > Test2.drl , number of rules fired = 1
>
> If someone allows me to open this a a JIRA i would try to understand how to
> use it :D and would do so.
>
> Regards,
> Manuel.
>
>
> 2009/7/13 Wolfgang Laun <wolfgang.laun at gmail.com>
>
> > Quite right, since not(not(Foo())) is equivalent to exists(Foo()).
> >
> > Martin, would you please submit a JIRA?
> >
> > -W
> >
> >
> >
> >
> >
> > On 7/13/09, Chivotario Martin <chivotario at gmail.com> wrote:
> > > Hi Visu,
> > >
> > > My understanding (also tested) is that activations are created no matter
> the
> > > knowledge base has the rule packages loaded
> > > before or after the working memory is filled with facts, but the
> execution
> > > of the rules happens automatically if the working memory is filled in
> > > advance.Setting the RuleBaseUpdateHandler to null, prevents the
> execution of
> > > the rules but keeps activations to be created when adding a rule to the
> > > kbase.
> > > In this case, it seems the exists CE only creates activations if the
> rules
> > > are loaded before the working memory is populated.
> > > But this doesn't happen if i change the statement :
> > >
> > > exists ( Foo() ) --> not ( not ( Foo() ) )
> > >
> > > In this case, activations are created no matter whether the kbase is
> empty
> > > or not before populating the WM.
> > >
> > >
> > >
> > >
> > > 2009/7/13 Viswanathan Nageswaran <visu.nageswaran at in.ibm.com>
> > >
> > > > Chivotario,
> > > >
> > > > >From what I understand, the activation of rules happen as facts are
> > > > inserted into the working memory; hence it is important for the
> session to
> > > > be begun against a knowledge base that has the rule packages loaded
> before
> > > > the facts are inserted.
> > > >
> > > > -Visu
> > > >
> > > >
> > > >
> > > >
> > > > Chivotario Martin
> > > > <chivotario at gmail
> > > > .com>
> To
> > > > Sent by: rules-users at lists.jboss.org
> > > > rules-users-bounc
> cc
> > > > es at lists.jboss.or
> > > > g
> Subject
> > > > [rules-users] "Exists" CE
> behaviour
> > > >
> > > > 13/07/2009 14:11
> > > >
> > > >
> > > > Please respond to
> > > > Rules Users List
> > > > <rules-users at list
> > > > s.jboss.org>
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > Hi ,
> > > >
> > > > I'm trying to use the Exists keyword within my rules with the
> following
> > > > snippet :
> > > >
> > > > // Create a session
> > > > KnowledgeBaseConfiguration config =
> > > >
> > >
> KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
> > > >
> > >
> ((RuleBaseConfiguration)config).setRuleBaseUpdateHandler(
> > > null ); *
> > > > KnowledgeBase kbase =
> > > KnowledgeBaseFactory.newKnowledgeBase(config);
> > > > StatefulKnowledgeSession session =
> > > kbase.newStatefulKnowledgeSession();
> > > >
> > > > // Add some objects
> > > > for (int i=0; i<5; i++) {
> > > > }
> > > >
> > > >
> > > > // Add a DRL to the kbase
> > > > KnowledgeBuilder kbuilder =
> > > KnowledgeBuilderFactory.newKnowledgeBuilder();
> > > > kbuilder.add( ResourceFactory.newClassPathResource(
> > > "test/existsTest.drl"
> > > > ), ResourceType.DRL);
> > > > kbase.addKnowledgePackages(
> > > kbuilder.getKnowledgePackages() );
> > > >
> > > > // Fire rules
> > > > int fireCount = session.fireAllRules();
> > > >
> > > >
> > > > existsTest.drl :
> > > >
> > > > rule "existsTest"
> > > > ( Foo() ) ); (2)
> > > >
> > > > end
> > > >
> > > > When launched , the rule is not fired (no messages , fireCount 0), but
> it
> > > > is when changing
> > > > exists with a double not condition (2).
> > > > If the working memory is populated after adding the rules file, the
> exists
> > > > CE works as expected.
> > > > * I've used no RuleBaseUpdateHandler preventing automatic activations
> to
> > > be
> > > > executed so fireAllRules can be used to get the fireCount, but
> commenting
> > > > this line out doesn't change the results.
> > > >
> > > > Probably i'm doing something wrong so a little help would be very
> > > > appreciated.
> > > >
> > > > Regards,
> > > > Manuel.
> > > > _______________________________________________
> > > > 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
> > > >
> > >
> > >
> > > _______________________________________________
> > > 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
> >
>
>
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