[rules-users] WorkflowProcessInstance in DRL

[Gareth Evans]

Hello,

I am having some problems using WorkflowProcessInstance in rules. I
have searched and not been able to find an answer to my question.

I am attempting to use rule flows to define business processes and
rules both in ruleflow groups to be executed on demand of the process
and outside of a ruleflow group for "global" rules and to potentially
direct the ruleflow(/process) is to run. Many of these processes are
comprised of subprocesses which I have been using sub flows to model.

I have used flow variables to store some minimal information about the
process such as what the process ID corresponds to in the existing
data model I am working with. My intent was so that I could use a
single rule flow group in many rule flows to extract information from
the database for the corresponding process ID in the working memory
(this extraction would also depend on other facts in the working
memory).

I've inserted the WorkflowProcessInstance by using an action node in
the "parent" process and it seems to work fine. My problem arises when
I am then in a "child" process/subflow and try to invoke this single
rule flow group with a different process ID in the flow variable,
there are no activations. I think this happens because the
WorkflowProcessInstance has not been updated in working memory so it
will not know that there might be a new process ID stored in the flow
variable (it has the same name in both flows as it is meant to
represent the same thing).

If I insert the WorkflowProcessInstance again in the sub flow I get
activations in the rule flow group for facts in the working memory
associated with both the parent and child sub flow which almost makes
sense except for this:

"We have added special logic to make sure that a variable
processInstance of type WorkflowProcessInstance will only match to the
current process instance and not to other process instances in the
Working Memory."

It seems that it is matching both instances of
WorkflowProcessInstance. I use the convention of starting variable
names from the LHS of a rule with a $ but I have tested it without and
I get the same result. Is this expected behaviour?

An alternative I've been trying to figure out is how to update the
WorkflowProcessInstance in working memory in the child process. Since
it is actually a different object I'm unsure how to do this. Should I
retract all instances and then insert the current? Is there a way to
do this more cleanly than looking through all working memory objects
and checking their type in an action node?

Finally (or perhaps firstly...), am I going about this correctly?

Cheers,
Gareth