[rules-users] Unable to resolve token on function call with mvel dialect

[Olivier THIERRY]

Well ... I found something very strange with Drools and mvel dialect
... It looks like Drools doesn't like points in function parameters !

I made this very simple test with a log function and the easier rule
you can have :

function void log (String message) {
	System.out.println(message);
}

rule "test"
	no-loop
	when
		eval(true)
	then
		log("hello world")
end

log("hello world") works ok
log("hello.world") (note the point) fails with this stack trace :

org.drools.spi.ConsequenceException:
org.mvel.UnresolveablePropertyException: unable to resolve token:
log("hello.world")
	at org.drools.base.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:13)
	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:558)
	at org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:518)
	at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:475)
	at org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:439)
	at t4.test.drools.TestRuleBase.executeRule(TestRuleBase.java:44)
	at t4.test.drools.Test1.testDebug(Test1.java:57)
Caused by: org.mvel.UnresolveablePropertyException: unable to resolve
token: log("hello.world")
	at org.mvel.ast.PropertyASTNode.initializePropertyNode(PropertyASTNode.java:129)
	at org.mvel.ast.PropertyASTNode.getReducedValueAccelerated(PropertyASTNode.java:24)
	at org.mvel.MVELRuntime.execute(MVELRuntime.java:90)
	at org.mvel.CompiledExpression.getValue(CompiledExpression.java:111)
	at org.mvel.MVEL.executeExpression(MVEL.java:235)
	at org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:48)
	at org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:554)
	... 34 more

It looks like there is a problem with point character, doesn't it ? Is
it a known problem ?

Regards,

Olivier


2008/12/15 Olivier THIERRY <olivier.thierry at gmail.com>:
> Thanks Edson. Here it is :
>
> rule "CALCUL_RELICAT_CP"
>        salience 8
>        no-loop
>        when
>                not $RELICAT_CP : VOCounter (code=="RELICAT_CP")
>                $startDate : RuleDate(name=="startDate")
>                $endDate : RuleDate(name=="endDate")
>                $SOLDE_CP_CUM : VOCounter ( code=="SOLDE_CP_CUM",
> startDate.year == ($startDate.year - 1) )
>        then
>                VOCounter $relicat = createCounter(drools,"RELICAT_CP",$SOLDE_CP_CUM.value);
>                insert($relicat);
>                insert(createCounter(drools,"SOLDE_RELICAT_CP",$SOLDE_CP_CUM.value));
> end
>
> I thought about trying with a newer version of mvel, but it doesn't
> look so easy to upgrade it :(
>
> 2008/12/15 Edson Tirelli <tirelli at post.com>:
>>
>>      Can you plz show us the DRL instead of the DSLR for your rule? use the
>> DRLViewer tab for that...
>>
>> 2008/12/15 Olivier THIERRY <olivier.thierry at gmail.com>
>>>
>>> Hi,
>>>
>>> I use drools 4.0.7 and I encounter a problem calling a function from a
>>> rule written for mvel dialect.
>>>
>>> The function I need to call has this signature :
>>>
>>> function VOCounter createCounter(org.drools.spi.KnowledgeHelper
>>> drools, String code, Number number)
>>>
>>> When I call this function, I want to assign result to a variable, for
>>> example to insert it to working memory later, or just to use it in
>>> another function call.
>>> So I wrote something like that (I am writing a DSL so part of the code is
>>> DSL ):
>>>
>>> rule "CALCUL_RELICAT_CP"
>>>        salience 8
>>>        no-loop
>>>        when
>>>                not There is a counter called "RELICAT_CP"
>>>                There is a date called "startDate"
>>>                There is a date called "endDate"
>>>                There is a counter called "SOLDE_CP_CUM" with
>>>                        - start date is last year
>>>        then
>>> >               VOCounter $relicat =
>>> > createCounter(drools,"RELICAT_CP",$SOLDE_CP_CUM.value);
>>> >               insert($relicat);
>>>                Copy counter $SOLDE_CP_CUM to SOLDE_RELICAT_CP
>>> end
>>>
>>> But I have the following stack trace :
>>>
>>> org.drools.spi.ConsequenceException:
>>> org.mvel.UnresolveablePropertyException: unable to resolve token:
>>> createCounter(drools,"RELICAT_CP",$SOLDE_CP_CUM.value)
>>>        at
>>> org.drools.base.DefaultConsequenceExceptionHandler.handleException(DefaultConsequenceExceptionHandler.java:13)
>>>        at
>>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:558)
>>>        at
>>> org.drools.common.DefaultAgenda.fireNextItem(DefaultAgenda.java:518)
>>>        at
>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:475)
>>>        at
>>> org.drools.common.AbstractWorkingMemory.fireAllRules(AbstractWorkingMemory.java:439)
>>>        at
>>> fr.horoquartz.t4.test.drools.TestRuleBase.executeRuleWithDsl(TestRuleBase.java:120)
>>>        at fr.horoquartz.t4.test.drools.Test1.testDsl(Test1.java:39)
>>> Caused by: org.mvel.UnresolveablePropertyException: unable to resolve
>>> token: createCounter(drools,"RELICAT_CP",$SOLDE_CP_CUM.value)
>>>        at
>>> org.mvel.ast.PropertyASTNode.initializePropertyNode(PropertyASTNode.java:129)
>>>        at
>>> org.mvel.ast.PropertyASTNode.getReducedValueAccelerated(PropertyASTNode.java:24)
>>>        at org.mvel.ExecutableAccessor.getValue(ExecutableAccessor.java:45)
>>>        at
>>> org.mvel.ast.TypedVarNode.getReducedValueAccelerated(TypedVarNode.java:43)
>>>        at org.mvel.MVELRuntime.execute(MVELRuntime.java:90)
>>>        at
>>> org.mvel.CompiledExpression.getValue(CompiledExpression.java:111)
>>>        at org.mvel.MVEL.executeExpression(MVEL.java:235)
>>>        at
>>> org.drools.base.mvel.MVELConsequence.evaluate(MVELConsequence.java:48)
>>>        at
>>> org.drools.common.DefaultAgenda.fireActivation(DefaultAgenda.java:554)
>>>        ... 34 more
>>>
>>> What is strange is that it works if I don't assign function call
>>> result to a variable. For example the following works  :
>>>
>>> insert (createCounter(drools,"RELICAT_CP",$SOLDE_CP_CUM.value));
>>>
>>> It also works if I assign $SOLDE_CP_CUM.value to a temporary variable
>>> and use it for function call :
>>>
>>> Number $val = $SOLDE_CP_CUM.value;
>>> VOCounter $relicat = createCounter(drools,"RELICAT_CP",$val);
>>> insert($relicat);
>>>
>>> I had not this problem using java dialect. I understand nothing in
>>> what happens ... Anyone has an idea what the problem is ?
>>>
>>> Thanks in advance,
>>>
>>> Olivier
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>>
>> --
>>  Edson Tirelli
>>  JBoss Drools Core Development
>>  JBoss, a division of Red Hat @ www.jboss.com
>>
>> _______________________________________________
>> rules-users mailing list
>> rules-users at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/rules-users
>>
>>
>
>
>
> --
> Seules 2 choses sont infinies : l'univers et la bêtise humaine ; et
> encore pour l'univers, je ne suis pas sûr … (Einstein)
>



-- 
Seules 2 choses sont infinies : l'univers et la bêtise humaine ; et
encore pour l'univers, je ne suis pas sûr … (Einstein)