conways game of life
by Mark Proctor
For anyone looking for a good and complex example on how to write rules
properly, please look at Conways Game of Life in drools-examples, for
extra bonus points compare it to the old version in M1. You'll see
nearly all the logic is moved from java to the drl and we have removed
the need for nested objects by using objects relaitionally, which also
allows us to exploit cross products to drive the application.
Mark
3 months, 1 week
Drools 4.0, Support for multiple pattern in accumulate source pattern
by Juergen
It appears as if accumulate does support only a single pattern CE as
source pattern, e.g.:
Number() from accumulate(
Cheese(
price : price
),
sum( price )
)
Is it possible to have more than one pattern in the source pattern, e.g.:
Number() from accumulate(
Cheese(
price : price,
type : type
)
Person(
favouriteCheese == type,
age > 30
),
sum( price )
)
The same could be said for collect, but there the problem to specify
which item of a matching tuple is to be collected, but this could be
handled recreating collect via accumulate, e.g.:
Collection() from accumulate(
cheese : Cheese(
type : type
)
Person(
favouriteCheese == type,
age > 30
),
collect( cheese )
)
15 years
JBoss Rules as a Daemon Service
by Arjun Dhar
Hi,
I uploaded the JBoss Rules 4 WAR; I saw the repository options but no admin
console to run a service. Maybe I'm missing something?!?!
Q) Being under the cover of the JBoss server am sure there must be some
fascility to run this as a daemon service 'out of the box'! Right?? <--
Important
(posted this 3 days ago but it got lost somwhere; prob deleted the approval
mail; FYI not being impatient :o) but its important so would like to know)
Thanks!
16 years, 9 months
Localization in DSL
by Shigeaki Wakizaka
Hello.
I'd like to use Japanese in DSL.
Is it possible?
Do you have a plan to do the localize-thing with DSL and
brand-new BRMS?
Thanks in advance
Shige
16 years, 10 months
Independent rule evaluations
by Yuri
Considering that I have a set of rules that can be time consuming to assert is
there a way to separate them from other rules without having to resort to
multiple working memories?
I basically want to be able to assert facts and evalute a set of rules as fast
as I can before actually having the time consuming set of rules evaluate.
thanks,
17 years, 2 months
Writing rules using java..
by Kolla, Sandeep
Hi Rahul,
Its not about storing the whole file into the database.
I would have a Table representing the parameteres required to construct
a rule.
For example.
Tables:
RuleSetTable:
Ruleset_id
Ruleset_name
RuleTable:
Rule_id
Rule_name
Rule_saliance
Rule_condition
Rule_consequence
Ruleset_id
Now while loading the rules the application basically should read from
the DB, and construct the rules, as everything required to construct the
rules is avaliable in the tables.
This requirement had come up because as the rules keep changing quite
frequently, we don't want to bring down the application to load a new
DRL file.
Hope you understood what I want to achieve.
Thanks much,
Sandeep.
17 years, 3 months
activationCancelled() not being executed?
by Fermion
Hi!
I'm using a JTable to display rules that have been activated.
My goal is to have the table display a set of activations ordered by their
salience. The user should then choose which one of them to fire (if you want
to know why, be invited to read the background).
Of course this makes only sense as long as the activations are valid. Rules
whose activation has been cancelled should still be displayed, but in a
different style (like greyed out).
In order to accomplish this, I want to use an implementation of the
AgendaEventListener-interface, implementing the
activationCancelled()-method.
The Listener itself works, as I use the activationCreated()-method to add
the rule as a row to my table (which works fine).
Unfortunately the activationCancelled()-method doesn't seem to be executed
at all!
I assume that I have a fundamental misunderstanding of what should trigger
an activationCancelled() event?
Background: (just if you're curious...)
I'm working as a PhD student in physics at the CERN international
high-energy physics laboratory, for the ATLAS experiment.
As a member of the Detector Control System (DCS) group, I'm going to write
an expert system in order to assist the shift crew with the detector
operation.
The operation of the detector is a difficult task, because more than 70000
parameters (like voltages, currents and temperatures) have to be controlled.
A Finite State Machine (FSM) computes a defined and limited number of states
from the given parameters (like ON, OFF, STANDBY,...).
I'm going to synchronize the expert system application to ERROR states of
the FSM, in order to extract the relevant parameters from the system (as it
would be impossible to feed all parameters into the XPS all the time).
This is handled by quite some control rules that decide which data has to be
requested, released and so on.
Once all necessary data has been received, this might lead to activations of
the (more interesting) user rules.
Those rules have an explanatory character like "The temperature of this XYZ
is too high, so please try ABC."
For a given set of facts I assume more then one rule to be activated. Whilst
the rule engine should take care of the execution (firing) of all control
related rules, the execution of the user rules should be under direct user
control.
Displaying all activations in a GUI will allow the user to pick one (try it)
and rate it (the proposed solution solved the problem "yes/no"). Changing
the rules salience according to the answer, will allow the system to
dynamically reflect the current system status. (Rules that are related to
broken connections / wrongly connected cables are likely to be found at the
beginning of the experiment but hopefully only on rare occasion later on.)
In order to ensure that no information is lost during the absence of DCS
experts (which will not always be around), a log file should be written for
each major FSM-ERROR. At the moment the WorkingMemoryFileLogger seems to be
predestined for this job. This way I hope to collect large amounts of ERROR
data during the initial phase of the experiment that helps to extract rules
for numerous error conditions.
This will become especially handy, as such errors have a tendency to come
back, even if the original detector experts are gone for years...
--
View this message in context: http://www.nabble.com/activationCancelled%28%29-not-being-executed--tf434...
Sent from the drools - user mailing list archive at Nabble.com.
17 years, 3 months
RE: Rules with Lookup Tables...
by Rahul Phadnis
Have you looked at
http://labs.jboss.com/portal/jbossrules/subversion.html
I think that page is not uptodate since at the bottom
it says "Trunk is unstable and may often not build. If
you wish to build form Subversion source the latest
tag is:
http://anonsvn.labs.jboss.com/labs/jbossrules/tags/3.0.3-GA/
"
Are n't we at 3.0.5 already?
-Rahul
--- jjdepaul(a)us.ibm.com wrote:
> Rahul -
>
> Where can I find Maven2 repository that has the
> nightly builds for Drools project?! I've looked
> around on a couple of well-known ones abut no luck
> finding anything above D3.0.5
>
> thanks,
> james
> >
> > The "from" CE (conditional expression) is not
> > available in the current released jboss rules
> version
> > (3.0.5) and you probably have to use the nightly
> build
> > to use it.
> >
> > -Rahul
> >
> >
>
>
17 years, 6 months
Accessing maps (hashmaps) keys and values in rules
by Ryan, Dennis (Dennis)
We are using Maps (HashMaps) in our rules and the only way we have found
to access keys and values in the Map in the "when" clauses is thru use
on eval() which I know is a big no-no by rules purists. Is there a
better way, maybe some shorthand I'm not familiar with to deal with Maps
in the when clause?
Thanks,
Dennis
17 years, 10 months
How do you use Ruleflows with StatelessSession's?
by Shahad Ahmed
Does anyone know if it's possible to use a ruleflow with a StatelessSession?
The current documentation and API seem to show examples with
StatefullSessions i.e.:
statefullSession.startProcess(id);
statefullSession.fireAllRules();
etc...
However, there doesn't seem to be anything equivalent in the API for
StatelessSesssion's. I'd really like to be able to use the new sequential
mode (i.e. with a StatelessSession) and ruleflow.
Regards,
Shahad
17 years, 10 months
