[rules-users] Nested properties and memberOf

[Meeraj Kunnumpurath]

I am able to enforce the order with the salience attribute.

I have a nested object graph, which in fact is a JAXB object generated from
Schema. I want to check an attribute nested three levels deep exists in a
collection. However, any of the intermediate levels in the graph could be a
null reference.

Regards
Meeraj

2010/7/16 David Sinclair <dsinclair at chariotsolutions.com>

> Ah, sorry, didn't realize that syntax wasn't supported in Drools. That
> being said, your rules may not fire in the order they are defined. (I forget
> what the default behavior as far as which rule would be activated first if
> all conditions were satisfied).
>
> What exactly are you trying to accomplish? It may be easier to write rules
> if you assert more of your object model into WM as opposed to the deep
> nesting. You'll also get performance improvements by doing so.
>
>
> dave
>
> 2010/7/16 Meeraj Kunnumpurath <mkunnumpurath at googlemail.com>
>
>> Hi Dave,
>>
>> I tried the null-safe navigation as below,
>>
>> rule "Check debtor account number exists"
>>     salience 1
>> when
>>     $c : CreditTransferTransactionInformation10(dbtrAcct.?id.?othr.?id not
>> memberOf accountNumbers)
>>     eval(!accountNumbers.contains($accountNumber))
>> then
>>     System.err.println($c.getInternalInfo().getStatus());
>>     System.err.println("Rule 2 executed");
>> end
>>
>> I get the error
>>
>> [29,57]: [ERR 102] Line 29:57 mismatched input '?' expecting 'identifier'
>> in rule "Check debtor account number exists" in pattern
>> CreditTransferTransactionInformation10
>> [29,61]: [ERR 102] Line 29:61 mismatched input '?' expecting 'identifier'
>> in rule "Check debtor account number exists" in pattern
>> CreditTransferTransactionInformation10
>> [29,67]: [ERR 102] Line 29:67 mismatched input '?' expecting 'identifier'
>> in rule "Check debtor account number exists" in pattern
>> CreditTransferTransactionInformation10
>>
>> Thanks
>> Meeraj
>>
>> On Fri, Jul 16, 2010 at 5:04 PM, Meeraj Kunnumpurath <
>> mkunnumpurath at googlemail.com> wrote:
>>
>>> 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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