[rules-users] Nested properties and memberOf

[Meeraj Kunnumpurath]

Hi Edson,

Just as a matter of interest ... How come the grammar recognizes the
null-safe accessors below

CreditTransferTransactionInformation10( eval( !( accountNumbers contains
dbtrAcct.?id.?othr.?id ) ) )

and not

CreditTransferTransactionInformation10(dbtrAcct.?id.?othr.?id not memberOf
accountNumbers )

Kind regards
Meeraj

On Fri, Jul 16, 2010 at 7:57 PM, Meeraj Kunnumpurath <
mkunnumpurath at googlemail.com> wrote:

> Thanks Edson.
>
> That worked like a treat
>
> CreditTransferTransactionInformation10( eval( !( accountNumbers contains
> dbtrAcct.?id.?othr.?id ) ) )
>
> Regards
> Meeraj
>
> 2010/7/16 Edson Tirelli <tirelli at post.com>
>
>    It does short circuit on "constraints". Not on patterns.
>>
>>    The problem is your assumption that rules are executed in order. They
>> are not. Check the manual for "Conflict Resolution".
>>
>>    Also, the LHS of rules are executed at "insert"/"modify" time, so the
>> LHS of both rules will be executed before any of them is fired.
>>
>>    The shortest syntax for your case is to use an mvel inline eval using
>> the null-safe navigation:
>>
>> rule X
>>     dialect "mvel"
>> when
>>     ...
>>     CreditTransferTransactionInformation10( eval( !( accountNumbers
>> contains dbtrAcct.?id.?othr.?id ) ) )
>>     ...
>>
>>    Of course, you can do all the null checks in the pattern itself,
>> avoiding the need to use the mvel syntax.
>>
>>    Edson
>>
>>
>> 2010/7/16 Meeraj Kunnumpurath <mkunnumpurath at googlemail.com>
>>
>>> Thanks Dave.
>>>
>>> I think the '||' on rule 1 is getting short-circuited. However, it is the
>>> '&&' on rule 2 that is not getting short circuited.
>>>
>>> Kind regards
>>> Meeraj
>>>
>>> 2010/7/16 David Sinclair <dsinclair at chariotsolutions.com>
>>>
>>> Drools doesn't use short circuit evaluation, so all of those ORs are
>>>> going to be evaluated. You may want to consider re-writing your rules or you
>>>> can use MVEL's null safe navigation for this. dbtrAcct.?id == null,
>>>> dbtrAcct.?id.?othr == nulll, etc.
>>>>
>>>> dave
>>>>
>>>>
>>>>
>>>> 2010/7/16 Meeraj Kunnumpurath <mkunnumpurath at googlemail.com>
>>>>
>>>>>  Hi,
>>>>>
>>>>> I have the following rules,
>>>>>
>>>>> global java.util.Set accountNumbers;
>>>>>
>>>>> rule "rule 1"
>>>>> when
>>>>>     $d : Document()
>>>>>     $c : CreditTransferTransactionInformation (dbtrAcct == null ||
>>>>> dbtrAcct.id == null || dbtrAcct.id.othr == null || dbtrAcct.id.othr.id== null) from $d.cstmrCdtTrfInitn.cdtTrfTxInf
>>>>>     $i : InternalInfo() from $c.internalInfo
>>>>> then
>>>>>     $i.setStatus(PaymentStatus.INVALID);
>>>>>     $i.setErrorCode("PR002");
>>>>>     $i.setAdditionalInfo("Account number is null");
>>>>> end
>>>>>
>>>>> rule "rule 2"
>>>>> when
>>>>>     $d : Document()
>>>>>     $c : CreditTransferTransactionInformation(internalInfo.status !=
>>>>> PaymentStatus.INVALID && dbtrAcct.id.othr.id not memberOf
>>>>> accountNumbers) from $d.cstmrCdtTrfInitn.cdtTrfTxInf
>>>>>     $i : InternalInfo() from $c.internalInfo
>>>>> then
>>>>>     $i.setStatus(PaymentStatus.INVALID);
>>>>>     $i.setErrorCode("PR002");
>>>>>     $i.setAdditionalInfo("Account number not available in the routing
>>>>> table");
>>>>> end
>>>>>
>>>>> My assumption is rule 1 and rule 2 will be executed in the order they
>>>>> appear. Rule 1 checks all the nested attributes are not null and set the
>>>>> status as invalid if any of them is null. Rule 2 uses the and operator and
>>>>> checks the nested attribute is in the collection defined by the global, only
>>>>> if the object is valid. I assume the LHS of rule 2 will be short circuited
>>>>> if the object is invalid. However, if any of the nested property is null I
>>>>> get the following exception from MVEL.
>>>>>
>>>>> Caused by: [Error: unable to access property (null parent): id]
>>>>> [Near : {... Unknown ....}]
>>>>>              ^
>>>>> [Line: 1, Column: 0]
>>>>>     at
>>>>> org.mvel2.optimizers.impl.refl.ReflectiveAccessorOptimizer.getMethod(ReflectiveAccessorOptimizer.java:861)
>>>>>
>>>>> Regards
>>>>> Meeraj
>>>>>
>>>>> _______________________________________________
>>>>> rules-users mailing list
>>>>> rules-users at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>>>
>>>>>
>>>>
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>>>>
>>>
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>>>
>>
>>
>> --
>>   Edson Tirelli
>>   JBoss Drools Core Development
>>   JBoss by Red Hat @ www.jboss.com
>>
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>>
>>
>
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