[drools-user] The DRL notation vs. jbossrules Rule Language - ?

[Dmitry Goldenberg]

I don't understand the relationship between the XML-based DRL notation and this 
new lingo with "when" / "then".
 
With the DRL notation, my understanding is that you write an XML structure like 
the one I'm including below.  How does this change with the when/then notation? 
 Thanks.
 

<?xml version="1.0"?>

<rule-set name="SamplePolicyRuleSet"

  xmlns="http://drools.org/rules";

  xmlns:java="http://drools.org/semantics/java";

  xmlns:xs="http://www.w3.org/2001/XMLSchema-instance";

  xs:schemaLocation="http://drools.org/rules rules.xsd 
http://drools.org/semantics/java java.xsd">

 

  <!-- Imports -->

  <java:import>java.lang.Object</java:import>

  <java:import>java.lang.String</java:import>

  <!-- Utility functions -->  

  <java:functions>

    public boolean f1(com.weblayers.platform.rule.PolicyExecContext context)

    {

        return ...;

    }

    public boolean f2(com.weblayers.platform.rule.PolicyExecContext context)

    {

        return ...;

    }

  </java:functions>

 

  <!-First Rule: IF (P1 AND P2) THEN RETURN OK -->

  <rule name="First Rule">

    <!-- Rule parameters -->

    <parameter identifier="context">

      <class>MyContext</class>

    </parameter>

 

    <!-- Rule Conditions -->

    <java:condition>

      f1() && f2()

    </java:condition>

 

    <!-- Rule Consequences -->

    <java:consequence>

       context.setReturn(Constants.OK);

    </java:consequence>

  </rule>

 

  <!-Second Rule: IF (!(P1 AND P2)) THEN RETURN FAILURE -->

  <rule name="Second Rule">

    <!-- Rule parameters -->

    <parameter identifier="context">

      <class>MyContext</class>

    </parameter>

 

    <!-- Rule Conditions -->

    <java:condition>

      !(f1() && f2())

    </java:condition>

 

    <!-- Rule Consequences -->

    <java:consequence>

       context.setVerdict(Constants.FAIL);

    </java:consequence>

  </rule>

 

</rule-set>