[rules-users] Absence Pattern question

[Michael Anstis]

Won't that just make the rule activate after 3 minutes?

rule AnoB
when
    $a: A( status == "waiting for B" )
    not B( this after [3m] $a )
then
    modify( $a ){ setStatus( "no B within 3m after me" ) }
end

Is this any good?

Also "untested" ;)

2011/7/5 Wolfgang Laun <wolfgang.laun at gmail.com>

> Try a rule with a timer:
>
> rule AnoB
> timer( int: 3m )
> when
>     $a: A( status == "waiting for B" )
>     not B( this after $a )
> then
>     modify( $a ){ setStatus( "no B within 3m after me" ) }
> end
>
> Untested.
> -W
>
>
>
> On 5 July 2011 13:00, wendy <w.mungovan at yahoo.com> wrote:
>
>> Hi,
>>  I'm having trouble writing an absence pattern.  What I'm trying to do is
>> detect when there is an A followed by no Bs for 3+minutes.  I don't care
>> if
>> there is more than one A.  What I'm running into is that when I try to use
>> 'over window:time' the time within drools is the end time of the window.
>>  So
>> this means I need to write the no Bs for 3+ min first:
>>
>> not( $b: B() over window:time(3m))
>>
>> then try to find the A before it:
>>
>> $now: Long() from RuleUtilityFunctions.getSessionClockTime()
>> $a: A( this before [3m] $now)
>>
>> then I should have to check to make sure that I don't have any Bs between
>> $a's time and the start of the no B window:
>>
>> not( B( time >= $a.time,
>>           time <= $now))
>>
>> This is not working.  I think that it has something to do with my function
>> to get the session clock time (RuleUtilityFunctions.getSessionClockTime())
>> and how things get evaluated within the Rete engine.  Because it does not
>> seem like $now is getting re-evaluated on future calls that pass the $b
>> condition.  If I replace $now with the call to getSessionClockTime()
>> everything just seems to get weird.
>>
>> I've tried to write the rule forward too.  Look for A followed by no B but
>> that does not seem to work because A is matched at the current time and
>> the
>> rule triggers because there is no B because the future B data has not be
>> inserted into working memory yet.
>>
>> What is the right way to write this rule?   Is there a way to get the
>> start
>> and end time of the time window that met the over window:time() condition?
>>
>> Thank you,
>> Wendy
>>
>>
>> --
>> View this message in context:
>> http://drools.46999.n3.nabble.com/Absence-Pattern-question-tp3140377p3140377.html
>> Sent from the Drools: User forum mailing list archive at Nabble.com.
>> _______________________________________________
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>> rules-users at lists.jboss.org
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>>
>
>
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