Liang,
As a rule of tumb, you should think about how many instances of objects
do you want to match in your rule each time. So, in your sample, if I
understood correctly, you want to match each RuleParam object against the
rule. This way, you should write only one column for the RuleParam object
type. Lets see an example of one possible way to write this rule:
rule "HealthRules_14" salience 65522
when
RuleParam( $healthPlan : healthPlan!="blank",
healthPlan!="refused",
$cr : changeReason -> ( $cr.equals("MA")
|| $cr.equals("CM") ) )
ICoverage(healthPlan != $healthPlan)
then
System.out.println("result = " + "error1");
end
Lets understand the rule: this rule will activate for each pair of
RuleParam and ICoverage instances in the working memory that match the
constraints:
RuleParam column. Any RuleParam instance that match ALL constraints bellow:
1) $healthPlan: healthPlan != "blank"
this is a simple literal constraint. We also bound the value of the
healthPlan attribute to the $healthPlan variable. Please note that the "$"
in the name of the variable is simply a best practice to allow one to easily
see where a variable is a bound variable. Any valid java identifier could be
used as a variable name.
2) healthPlan != "refused"
another simple literal constraint.
3) $cr : changeReason -> ( $cr.equals("MA") || $cr.equals("CM") )
this is a predicate constraint. First we bind the $cr variable to the
changeReason attribute, and the we evaluate a java expression that must
return "true" or "false".
If all above constraints return true, the RuleParam instance is matched
and will try a join with all instances of ICoverage in the working memory.
The join constraint is:
1) healthPlan != $healthPlan
A variable bound constraint that will check if the healthPlan attribute
of the ICoverage instance is different from the value of the previously
bound variable.
If all previously constraints are met, the rule is triggered for that
pair of [RuleParam, ICoverage] instances.
I hope it helps. If it is not clear, let me know and I try again. :)
Regards,
Edson
----- Original Message -----
From: "Liang Gao" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, April 16, 2006 1:37 AM
Subject: [drools-user] I need your help!!!
> I am new to Drools 3. My DRL dile is compiled and the test program runs
well, however, the result is NOT my expectation. According to the input, it
should output "Result = error1", but it print NOTHING.
>
> It works if I change lines <1> and <2> of the drl file to:
ICoverage(healthPlan!="plan2"). So I guess the problem should come from
"RuleParam(p:healthPlan)". I have checked the documentation of Drools 3 and
the testing code in
http://anonsvn.labs.jboss.com/labs/jbossrules/trunk/drools-compiler/src/test
/resources/org/drools/integrationtests/not_with_bindings_rule_test.drl. But
I didn't find out the reason.
>
> Does anybody know why? The following is my source code that runs on
Drools3 RC2.
>
> Thanks a lot.
>
> Liang
>
>
============================================================================
===============
>
> My drl file:
> --------------------------------------------------------------------------
-----------------
> package gov.sc.eip.rules;
> #generated from Decision Table
> import java.lang.String;
> import gov.sc.eip.model.ICoverage;
> import gov.sc.eip.helper.IConstants;
> import gov.sc.eip.rules.test.RuleParam;
>
> #From row number: 14
> rule "HealthRules_14"
>
> salience 65522
> when
> RuleParam(changeReason=="MA") || RuleParam(changeReason=="CM")
> RuleParam(healthPlan!="blank") && RuleParam(healthPlan!="refused")
> <1> RuleParam(p:healthPlan)
> <2> ICoverage(healthPlan!=p)
> then
> System.out.println("result = " + "error1");
> end
> ---------------------------------------- drl
end ------------------------------------------
>
> Snippet of Test program
> --------------------------------------------------------------------------
-----------------
> ICoverage coverage = new Coverage();
>
> //paremeter
> RuleParam params = new RuleParam();
> params.setChangeReason("MA");
> params.setHealthPlan("plan2");
>
> //ICoverage object
> coverage.setHealthPlan("plan1");
>
> t.engine = t.ruleBase.newWorkingMemory();
> t.engine.assertObject(params);
> t.engine.assertObject(coverage);
>
> t.engine.fireAllRules();
> --------------------------------------------------------------------------
-------------------
>
>
>
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