Re: [rules-users] Intermediate conclusions using strings
We've encountered a similar situation where there were many paths to
the same conclusion, and we needed to track them. We found the best way
was to create a new Object that is created in the lhs and inserted.
The below pseudo code should illustrate what I'm talking about.
Hopefully it makes sense:
public class MembershipLevel{
private Person person;
private Date memberSince;
private Level level;
private Number revenue;
public MembershipLevel(Person person, Date memberSince, Level level,
Number revenue){
...
}
//getters and setters
//appropriate equals/hashCode
}
rule "gold member if revenue per month > 1000"
when ...
then
insert( new MemberShipLevel(person, Level.GOLD, revenue);
end
rule "gold member since 1999 gets a t-shirt"
when
m:MemberShipLevel( memberSince < '2000-01-01');
then
TShirtFactory.sendShirtTo(m.getPerson());
end
This allows you to have more than one person in the engine at once,
and you can track what caused the calculations.
On Aug 25, 2008, at 6:09 AM, David Boaz wrote:
Hi all,
I have an idea and I want to get the community feedback.
Many times there are many ways to reach an intermediate conclusion.
This
conclusion can be used to derive higher level conclusions or actions.
For example, assuming a credit application has several (or) options to
conclude whether a parson is classified as gold member. Then, other
rules
need this information to determine the credit limit for that member.
To
note, the Person java class doesn't have a specialized attribute for
the
classification. The classification is only an internal means to
simplify the
application logic.
To solve that problem, I thought to insert a string conclusion to
the WM.
Something like:
rule "gold member if revenue per month > 1000"
when ...
then insert("gold member")
end
rule "gold member if total amount > 1000000"
when ...
then insert("gold member")
end
...
rule r100
when String(value=="gold member")
then...
end
* Is it an appropriate approach?
* I know it ugly to use the same string literal in various rules.
Can we
avoid that?
* Is there a known mechanism to handle these cases?
Thanks, David
--
View this message in context:
http://www.nabble.com/Intermediate-conclusions-using-strings-tp19141834p1...
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