[rules-users] Working with dates in rules

[David Siefert]

Not sure--Drools 5 temporal reasoning looks like it would be the answer.
Only problem is that I need a solution now, so I am stuck with Drools 4.

This did give me some ideas though.  I created myself a class called
TemporalReasoner.  This has a few methods, namely to roll a date (so I can
tell it x amount of time from now), and then compare it to another date.

So in my rule, lets say I have a fact CreditCard with property
expiration:Date (speaking uml-ishly for "a property named 'expiration' of
type Date"):

rule "Fires when expiration less than today"
  when
    $c: CreditCard($expires : expirationDate)
    eval(new TemporalReasoner(Calendar.getInstance()).lessThan($expires))
  then
    // do something for when credit card is still valid
end

Now, I'm still generally a noob with BRs, so I'm not sure how this will
affect performance.  Any advice?

Thanks,
David

On Thu, Jan 29, 2009 at 3:50 AM, Anstis, Michael (M.) <manstis1 at ford.com>wrote:

>  Hi,
>
> I wonder whether Drools 5 "Complex Event Processing Support (Temporal
> Reasoning)" might be what you're looking for?
>
> http://blog.athico.com/2008/07/drools-50-m1-new-and-noteworthy.html
>
> With kind regards,
>
> Mike
>
>  ------------------------------
> *From:* rules-users-bounces at lists.jboss.org [mailto:
> rules-users-bounces at lists.jboss.org] *On Behalf Of *David Siefert
> *Sent:* 29 January 2009 09:40
> *To:* Rules Users List
> *Subject:* [rules-users] Working with dates in rules
>
>   Hi-
>
> I'm wondering how it would be possible to compare a part of a date in the
> lhs condition of a rule in a Drool.  In other words, I need to compare a
> date to see if it is *x* days from the current date, *n* hours from
> current time, etc.  Would anyone be kind enough to provide an example?  I'm
> thinking I may have to implement something of my own to offer that
> functionality?
>
> Big thanks,
> David
>
>
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