To demonstrate the issue I have simplified the following sample rule to just the components needed to demonstrate the issue. The example rule I’m posting here uses the “after” operator; I have also tried this same test with the before operator. In this sample the rule named “AfterRule” will activate if the facts are initially inserted in a state matching the pattern. However, if the facts are inserted in a state that does not match, and then later updated to match the pattern using StatefulKnowledgeSession.update() the rule will not activate.

Consider the following DRL:

package test.rules;

dialect "java"

import java.util.Date;

import com.p1s.mps.model.RuleTime;

import com.p1s.mps.model.Patient;

declare RuleTime

    @role( event )

    @timestamp( time )

end

declare Patient

    @role( event )

    @timestamp( birthDate )

end

rule "AfterRule"

when

    $now : RuleTime(  )

    Patient( this after $now )

then

      System.out.println("after");

end

Separately in a unit test the following actions are performed:

1. Insert an instance of RuleTime into the session where time is set to now.

2. Insert an instance of a patient into the session where the birthdate is set to (now – 1 day). [This makes the birthdate in the past so the rule does not activate]

3. Call fireAllRules(). The rule does not activate, as expected.

4. Modify the patient instance to have a birthdate set to (now + 1 day).

5. Invoke update() on knowledge session.

6. Call fireAllRules(). The rules does not activate. It should activate here.

If I change step 5 to a retract + insert then the rule will activate in step 6 as expected.

Thank You,

Nathan Bell