[rules-users] Separate selectable drl files in drools kbase.. Or agenda groups

[Wolfgang Laun]

On 05/06/2013, Ramon Buckland <ramon at thebuckland.com> wrote:
> Hi Wolfgang,
>
> Thanks for the suggestions. I have a few questions, does changing the focus
> on the RHS work like :
>
> kcontext.getKnowledgeRuntime().getAgenda().getAgendaGroup( "B to D"
> ).setFocus();

Looks like it.

>
> Do I need to import kcontext ? or is it implicitly in scope already ?

No, cf. "The Right Hand Side (then)" (Expert manual).

>
>> a low salience rule would set
>> the AG for the Spartan group and so on.
>
> As I understand it, salience helps the engine decide "which" rule to run,
> when one or more matches, but does that mean identical factors ,,
> or just any that are applicable ?

A LHS is either matching or not. Salience just orders activations for firing.


>
> Will the below example work ? Will "b only" fire last like I want it to ?

Yes (unless one of the "then ..." decides to retract or change Foo).

Note that

rule "proceed to Worker Group"
salience -1000
when
then
kcontext.getKnowledgeRuntime().getAgenda().getAgendaGroup(
"WorkerGroup" ).setFocus();
end

would be sufficient to proceed in any case, not requiring some fact to
meet some constraint, which may or may not be preferable.

-W


>
> class Foo { boolean a; boolean b; }
>
> (object inserted has a and b == true), Agenda-group Focus is set to
> "Intialisation"
>
> ---
> rule "a only"
> agenda-group "Initialisation"
> salience 10
> when
>      Foo (a == true)
> then
>      …
> end
>
> rule "a and b"
> agenda-group "Initialisation"
> salience 5
> when
>      Foo (a == true, b == true)
> then
>      …
> end
>
> rule "b only"
> agenda-group "Initialisation"
> salience 1
> when
>      Foo (b == true)
> then
>     kcontext.getKnowledgeRuntime().getAgenda().getAgendaGroup( "WorkerGroup"
> ).setFocus();
> end
>
> Many thanks
> Ramon
>
> Ramon Buckland
> ramon at thebuckland.com
>
>
>
> On 5 Jun 2013, at 06:47, Wolfgang Laun <wolfgang.laun at gmail.com> wrote:
>
>> You can change the focus on the RHS of a rule as well, using the API.
>> Starting in the default agenda group, a low salience rule would set
>> the AG for the Spartan group and so on.
>>
>> Notice that any attribute can be set in front of or in between rules to
>> become effective in successive rules. This should also work in XLS,
>> except that you may have to create three files for your three groups.
>> (The XLS parser isn't very intelligent, at least wasn't last time I was
>> looking.)
>>
>> -W
>>
>>
>> On 04/06/2013, Ramon Buckland <ramon at thebuckland.com> wrote:
>>> Hi,
>>>
>>> I am using a Stateless Knowledge session backed behind a web rest api.
>>> The rest api is provided by spring Mvc, so I have a stateless ksession
>>> injected in.
>>>
>>> As it is stateless, I have found it difficult to use agenda groups to
>>> meet my need. And have a question to how I set this up.
>>>
>>> My task.
>>> In short, I have 10 or so set up rules (init rules), then a 300 odd
>>> (work) rules, then I need to fire a few (5) (finalisation) rules.
>>>
>>> They need to be processed in that order. If I were using stateful I
>>> see how an agenda group solves that need.. In the calling java that is
>>> nice. setFocus().. But stateless blocks that api.
>>>
>>> So I have attempted with auto-focus..
>>>
>>> In the DRL (from XLS) however getting the agenda group settings right
>>> has been a small 'mare. Suffice to say I haven't got it working.
>>>
>>> My options:
>>> 1. get agenda groups working.
>>> 2. split the three groups into 3 DRL files. and execute in sequence
>>> each one using a different ksession for each.
>>>
>>> --- on 1.
>>>
>>> How would I construct the flow.. .. Do I use three separate auto focus
>>> rules , one for each a.group  and set a salience ( I don think
>>> salience helps here ) ? How do I guarantee to stack the focus using
>>> auto-focus to follow my ordering?
>>>
>>> -- on 2.
>>> Can I create a separate ksession for each DRL file (injecting them in
>>> from spring).
>>>
>>> --
>>> Thoughts ? Am I solving right ?
>>>
>>> Many thanks. Ramon
>>> _______________________________________________
>>> rules-users mailing list
>>> rules-users at lists.jboss.org
>>> https://lists.jboss.org/mailman/listinfo/rules-users
>>>
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