How to make the rule is executed as expected flow in drools - drools

Question

The the following logic:
if (order.getPrice()<200 ) {
order.setPrice(order.getPrice()-10);
} else {
order.setPrice(order.getPrice()-20);
if (order.getPrice()<200 ) {
//do nothing
}else {
order.setFreeShip("true");
}
}
for above logic, if I want to implement in drools rule.
rule "rule 1"
when
$o:Order ( amount<200);
then
$o.setPrice($o.getPrice()-10);
end
rule "rule 2"
when
$o:Order (amount>200);
then
$o.setPrice($o.getPrice()-20);
end
If the fact's price is 210, the rule2 is activated then the rule1 will be fired. That is not expected. I don't want to retract(). So is there any better solution for this issue?
And can I specify the sequential rule once a rule is executed like a token mechanism.
Thanks.

Answer 1

No, you can't specify sequential for just one rule or group of rules. You'll need to create a flag and use it as a guard, for example:
rule "rule 1"
when
$o:Order ( amount<200);
not: Flag(object=$o)
then
$o.setPrice($o.getPrice()-10);
insert( new Flag($o) );
end
rule "rule 2"
when
$o:Order (amount>200);
not: Flag(object=$o)
then
$o.setPrice($o.getPrice()-20);
insert( new Flag($o) );
end
and
public class Flag {
private final Object object;
public Flag(Object o) {
this.object = o;
}
//add getter for object
//delegate equals and hashcode to object
}

Answer 2

rule "NYuser_Rule"
no-loop true
ruleflow-group "EvalLoopcondition"
when
m:HelloProcessModel(userlocation in ("NewYorkUser"), count < 4)
then
m.setLoopcondition(6);update(m);
end
rule "ChileUser_Rule"
no-loop true
ruleflow-group "EvalLoopcondition"
when
m:HelloProcessModel(userlocation in ("ChileUser"), count < 3)
then
m.setLoopcondition(5);update(m);
end
Something like this can help you out.