2009/10/16 leif hanack <leif.hanack@hypoport.de>

Hi,
since Drools 5 it is possible to define a dynamic variable holder by
using the declare notation. This feature is really cool.
I can create easily helper rules, that calculate temporary values:

File: calculate_total_amount.drl

declare TotalAmount
amount : Money
end

rule "calculate total amount"
when
..
then
TotalAmount totalAmount = new TotalAmount();
totalAmount.setAmount($calculatedAmount);
insert(totalAmount);
end

Inside another file I use this helper.

File: another_rule.drl

rule "another rule"
when
TotalAmount( amount > 1000)
then
// do s.th.
end

I unit test my rule by querying a fact and verify my assertions. This
works fine, as long as the fact is a class of my factmodel.
Now my question: Is there a way to query a declared class (in this
case TotalAmount)

I tried it with some variations but without success:

import my.package.of.the.rule;
query "get total amount"
amount : TotalAmount()
end

I thought that a declare is compiled to a class, but I can not find it
in the generated classes.
Did you have any help?

An alternative might be to create a holder class. S.th. like that

rule "calculate total amount"
..
then
TotalAmount totalAmount = new TotalAmount();
totalAmount.setAmount($calculatedAmount);
insert(totalAmount);
Holder holder = new Holder();
holder.setObject(totalAmount);
insert(holder);
end

import my.package.holder;
query "get holder"
holder : Holder()
end

Thanks in advance, Leif
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