[rules-users] Complex rule

[Edson Tirelli]

   I just gave a "name" to your anonymous objects... :)

"I have a list of objects that contain date objects. If the list contains 10
objects that date are before mine then I want them to take a break."

   So, replace this Day object for whatever you have in your business domain
model. Also, I added "status == Day.WORKED" to represent whatever constraint
you use do differentiate working days from non-working days... so, in other
words, that was just me guessing a scenario similar to yours but probably
coming up with something completely different... ;)

   []s
   Edson

2008/11/4 Bryan Hansen <bryankhansen at gmail.com>

> Thank you Edson, this helps me get going in the right direction.
>
> In this logic:
>
> Period( $sd : startDate, $ed : endDate )
>     Number( intValue > 10 ) from accumulate(
>          Day( date >= $sd && <= $ed, status == Day.WORKED ),
>          count( 1 ) )
>
> Where is date coming from? As I read the statements, I am getting startDate
> and endDate from a Period object that I pass in. The Number() statement just
> says to take the result and parse it as a number right? What about Day and
> date though? Is Day a java object from my Java code? I searched the docs
> looking for a Day object in the drools docs and didn't come up with
> anything. I am assuming it is because of the Day.WORKED status, would date
> just be a member of that object?
>
> Thanks,
>
> Bryan
>
>
> On Mon, Nov 3, 2008 at 7:51 PM, Edson Tirelli <tirelli at post.com> wrote:
>
>>
>>    Bryan,
>>
>>    The main decision here is how to do Date arithmetic, since java does
>> not provide easy to use APIs for that. So, the simplest way IMO, from a rule
>> authoring perspective, is to have a "constraint object" that contain both
>> boundary dates of your rule. Lets call it "Period".
>>    So, if you want to write your rule saying:
>>
>> "Take a break if you worked more than 10 days in the given period."
>>
>>     Just do:
>>
>> rule "take a break"
>> when
>>     Period( $sd : startDate, $ed : endDate )
>>     Number( intValue > 10 ) from accumulate(
>>          Day( date >= $sd && <= $ed, status == Day.WORKED ),
>>          count( 1 ) )
>> then
>>     // take a break
>> end
>>
>>     If your Day object is some kind of container object, use a chained
>> from to iterate over them:
>>
>> rule "take a break"
>> when
>>     Period( $sd : startDate, $ed : endDate )
>>     DailyReport( $days : days )
>>     Number( intValue > 10 ) from accumulate(
>>          Day( date >= $sd && <= $ed, status == Day.WORKED ) from $days,
>>          count( 1 ) )
>> then
>>     // take a break
>> end
>>
>>    Hope it helps.
>>
>>      Edson
>>
>> 2008/11/3 Bryan Hansen <bryankhansen at gmail.com>
>>
>>>  Not really sure how to go about writing this in a rule or whether or not
>>> the logic belongs in a rule (I think it does, but if you don't please
>>> comment as to why).
>>>
>>> I have a list of objects that contain date objects. If the list contains
>>> 10 objects that date are before mine then I want them to take a break.
>>>
>>> The business case is similar to that of an HR system. If they have worked
>>> too many days out of the last 12 then they need to take a break.
>>>
>>> I am guessing it would have to use the "collect" attribute, but how would
>>> you do the date logic in a LHS clause?
>>>
>>> Thanks for any guidance on this.
>>>
>>> _______________________________________________
>>> 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
>>
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>>
>>
>
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>


-- 
 Edson Tirelli
 JBoss Drools Core Development
 JBoss, a division of Red Hat @ www.jboss.com
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