[rules-users] Firing Rules in Rule Flows

keithnielsen keithnielsen at discover.com
Thu Jan 15 18:22:21 EST 2009


I have a fairly involved rule flow consisting of rule flow groups. I am
trying to understand 
if the behavior I am seeing and my understanding of it are correct. 

The flow executes as exepected the first pass through, objects are inserted
and the rules associated with the different nodes are executed. On the
second pass through the flow various nodes are triggered but none of the
ruleflow groups are activated/executed. My understanding of this is as
follows: 

1) The only way to have these ruleflow groups fire/execute again is to
insert objects that cause a match or to fire all rules on the session again. 
2) Constraints on split/join nodes are always evaluated and don't need to be
activated which is different than the constraints on a given rule 
3) Rules that don't have any constraints, i.e. they are always true will
only execute once and will only execute with a call to fire all rules 

Assuming my understanding of what is going on correct I have the following
questions: 

Q. My particular use case is really screen flow/business process, and it
would be nice if I came to a node, that the rule was always evaluated, i.e.
currently rules that always evaluate to true aren't fired more than once.
For instance I have a node that simply instantiates a dialog and waits for
user input and I always want to instantiate that dialog when I come to that
node, regardless of the facts. Is there a way to achieve this without firing
all rules again? 
Q. Is firing all rules within a rule flow a legitimate way of achieving the
desired affect? 

Shouldn't the ruleflow-group associated with a node always be evaluated if
the node is triggered? As it happens now, the rule flow gets stuck in an
infinite loop as the node contraints are conitniously evaluated but the
actual rule contraints are not. Seems inconsistent too me especially in the
context of a business process/rule flow.

Thanks 



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