[rules-users] Dynamic rules and inheritance

[ventilo35]

Hi
I'm exploring using dynamic rules (using Drools 6.0.0 Final), and I see a 
curious behaviour when the knowledge is built using inheritance. 
What I notice is
- new rules which have conditions based on subclasses are fired all right
- but new rules which have conditions based on the base class are not always 
fired
- they are fired only if some initial rules where fired, based on the base 
class (?!?)

Here is an runnable example for clarity:


// knowledge classes
public static class Person {
    
        private String firstName;
        private String lastName;
        
        public void setFirstName(String fname) {
                this.firstName = fname;
        }
        public void setLastName(String lname) {
                this.lastName = lname;
        }
        public String getFirstName() {
                return this.firstName;
        }
        public String getLastName() {
                return this.lastName;
        }
    }

public static class Contact extends Person {
    
        private String msisdn;
        
        public void setMsisdn(String m) {
                this.msisdn = m;
        }
        
        public String getMsisdn() {
                return this.msisdn;
        }
    }



// Drools session

KieServices ks = KieServices.Factory.get();
KieModuleModel kieModuleModel = ks.newKieModuleModel();


KieBaseModel kieBaseModel1 = kieModuleModel.newKieBaseModel( "rules")
                        .setDefault( true )
                        .setEqualsBehavior( EqualityBehaviorOption.EQUALITY )
                        .setEventProcessingMode( EventProcessingOption.STREAM );


KieSessionModel ksessionModel1 = kieBaseModel1.newKieSessionModel( "KSession1" )
                        .setDefault( true )
                        .setType( KieSessionModel.KieSessionType.STATEFUL )
                        .setClockType( ClockTypeOption.get("realtime") );
                
KieFileSystem kfs = ks.newKieFileSystem();
                
ReleaseId ri = ks.newReleaseId( "org.default", "artifact", "1.0.0" );
kfs.generateAndWritePomXML(ri);

// initial rules
kfs.write("src/main/resources/rules/initial.drl", 
ks.getResources().newFileSystemResource("src/main/resources/rules/initial.drl").setResourceType(ResourceType.DRL));

KieBuilder kieBuilder = ks.newKieBuilder( kfs ).buildAll();
KieContainer kContainer = ks.newKieContainer(ri);
KieSession kSession = kContainer.newKieSession();

Contact alice = new Contact();
alice.setFirstName("Alice");
alice.setLastName("Doe");
kSession.insert(alice);

Contact bob = new Contact();
bob.setFirstName("Bob");
bob.setLastName("Tester");
kSession.insert(bob);

kSession.fireAllRules();

// new rules
kfs = ks.newKieFileSystem();
ReleaseId ri2 = ks.newReleaseId( "org.default", "artifact", "1.1.0" );
kfs.generateAndWritePomXML(ri2);
kfs.write("src/main/resources/rules/initial.drl", 
ks.getResources().newFileSystemResource("src/main/resources/rules/initial.drl"));
kfs.write("src/main/resources/rules/newrules.drl", 
ks.getResources().newFileSystemResource("src/main/resources/rules/newrules.drl"));
kieBuilder = ks.newKieBuilder( kfs ).buildAll();
kContainer.updateToVersion(ri2);

kSession.fireAllRules();




initial.drl :

package com.sample

import com.sample.DroolsTest.Person; 
import com.sample.DroolsTest.Contact;


rule "Hello World 1"
when
        c: Contact()
then
        System.out.println("initial, working, found Contact 
"+c.getFirstName()); 
end

rule "Hello World 2"
when
        p: Person()
then
        System.out.println("initial, working, found Person "+p.getFirstName()); 
end





newrules.drl :

package com.sample

import com.sample.DroolsTest.Person; 
import com.sample.DroolsTest.Contact;


rule "Hello World 3"
when
        c: Contact()
then
        System.out.println("new rule, working, found Contact 
"+c.getFirstName()); 
end

rule "Hello World 4"
when
        p: Person()
then
        System.out.println("new rule, working, found Person 
"+p.getFirstName()); 
end


This examples produces :
initial, working, found Contact Bob
initial, working, found Contact Alice
initial, working, found Person Bob
initial, working, found Person Alice
new rule, working, found Contact Bob
new rule, working, found Contact Alice
new rule, working, found Person Bob
new rule, working, found Person Alice

But, if you comment out rule #2 in initial.drl, then the output becomes:
initial, working, found Contact Bob
initial, working, found Contact Alice
new rule, working, found Contact Bob
new rule, working, found Contact Alice

i.e. rule #4 isn't fired anymore...

Is this explainable? 

Thanks
Francois

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