[rules-users] How to pass global variables to a function called in a condition

[Wolfgang Laun]

Conditions are evaluated when facts are inserted, modified and deleted.
-W


2011/8/25 Matthew Erler <wires8 at yahoo.com>

> In Drools 5 I'm passing in two global Date objects and need to find the
> difference in days between them.  I've discovered that the function
> parameters (fromDate and toDate in my case) are null in the condition when
> the function is called, but when the function is called in the consequence
> they have values.  I can see that because the output of the following rule
> is:
> fromDate is null
> toDate is null
> I'm in dateDiff and the date diff is: 14
>
> I'm guessing that Drools doesn't make globals t available at the point that
> I need them.  Can anyone confirm this and offer a solution?
>
> Here is the rule file itself:
>
> import java.util.Date;
> import org.joda.time.DateMidnight;
> import org.joda.time.Days;
>
> global java.util.Date fromDate;
> global java.util.Date toDate;
>
>
> rule "dateDiff"
> dialect "mvel"
>      when
>           eval(getDaysBetweenStartAndEndDate(fromDate, toDate) < 10)
>      then
>           System.out.println( "I'm in dateDiff and the date diff is: "
> +        getDaysBetweenStartAndEndDate(fromDate, toDate));
> end
>
>
> function int getDaysBetweenStartAndEndDate(Date fromDate, Date toDate) {
>     if (fromDate==null) System.out.println("fromDate is null");
>     if (toDate==null) System.out.println("toDate is null");
>   return Days.daysBetween(new DateMidnight(fromDate), new
> DateMidnight(toDate)).getDays();
> }
>
> _______________________________________________
> rules-users mailing list
> rules-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/rules-users
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/rules-users/attachments/20110825/4ddeb62a/attachment.html