Re: [rules-users] Evaluate rules for multiple facts of the same type within a StateuflSession
On 18/02/2013, pdario <dario.piantanida(a)gmail.com> wrote:
Hello, the "tinting" example from the whitepaper assumes
each Tint fits
exactly one Param, right?
This is not my case, as a Cart can match different discounts and we want to
assign the highest possible.
There is always just one fit; it just seems that there are multiple
fits - when you define your individual cases sloppily. The correct
definition must be extended to exclude any fit with a smaller discount
:-)
Is the pattern still suitable?
Certainly, the rule merely has to be a little more circumspect when
overlaps are possible, excluding the match of another set of values
with a higher discount.
Another thing I see is Param is evaluating plain attributes from the Tints,
but (not sure if this is the correct pattern) I'm using this to find if a
Cart contains a specific item
when
Cart ($items : buyingItems, payment == Card....)
i : Item (code == XXXXX) from $items
then
I don't see why "XXXXX" shouldn't come from a parameter fact.
As a general strategy, I try to avoid the "on-the-fly" objects
available with "from" and prefer these subordinate items to be
properly inserted facts. Usually this simplifies writing rules.
-W