Decision tables
by Chris Richmond
Hello,
What is the most straightforward example of using a decision table for
rules(CSV or Excel) within the sample code?
Essentially I want to check if it would work for the usage case where I want
the end user to be able to set all sorts of parameter limit values for rules
on objects being evaluate by rules. Also I would like for them to be able
to set limits on combinations of objects via decision tables. Allowing the
user to state specifically in the decision table something like:
If I have more than 3 of these objects then look at the fieldB of all these
objects, if any of these have "X" for fieldB then look at fieldC for all of
them and sum the total of all fieldC 's for all objects in memory and if
that number is above "Z" then do something
But if there are less than 3 but more than 1(essentially 2) of these
objects, then simply look at fieldC for both objects and reset fieldD for
whichever object has a lower value for fieldM.
Can decision tables be made to handlie this sort of flexible and extensible
decision matrix, or would that not be good fit for scenarios like this?
Thanks,
Chris
16 years, 8 months
Drools fusion and absence of events
by Richard Ambridge
Hi,
Trying to get to grips with Fusion and absence of events...
If I have a Bean that has just a simple variable, e.g. class
MyBean { private String name; getter+setter }
I want to use events to determine when an object with name=="one"
is available, and no object with name=="two" appears within 10 seconds..
So, I write a rule:
declare MyBean
@role( event)
end
rule "myrule'
when
$a : MyBean(name=="one");
not( MyBean(name=="two", this after [0s,10s] $a))
then
//do something
end
If I inject an object with Name="one", and then wait 10seconds, I
get the 'myrule' fired, great!
But, if i inject an object with name="one" and then 1second later I
inject an object with name="other"
the 'myrule' is fired..
Looking at the manual, this seems kind of correct, the rule says if
I have a "one" and not a bean with name=="two"
which I do, as I have a 'one' and a 'other'
But, how do I write the rule to say, I have a 'one' and 'two' doesn't
turn up?
Cheers
Ric
16 years, 8 months
question about Process Instances
by Daniel Miller
Another question about Process Instances:
Is there a way to inject variables into a running process instance? I
know when I start the process I can pass a Map of variables, but is
there a way to continue injecting variables -- like
processInstance.setVariable("myVariable",myValuedObject); ?
Thanks,
Dan Miller
16 years, 8 months
Question about signalEvent method
by Daniel Miller
Alright, I feel dumb posting this question, but I can't seem to find
an answer anywhere.
When I use signalEvent, I know I'm passing it the event I want to
fire, but then there is the "Object event" parameter. What exactly
happens if I fill this parameter? What I'd like to do is the following:
Get a running process id, and signal an event on the process -- in my
case "AttachAudio". However, the AttachAudio is going to be proceeded
by an action, which will be responsible for actually attaching my
audio object to a running Alert in my system.
So, obviously I need to inject the audio object into my process
instance. Is that what the "event" parameter does on signalEvent?
And if so, how does it know what variable to inject the object into?
If not, how can I do something like processInstance.setVariable
("audio",audioObject); processInstance.signalEvent
("AttachAudio",null); ?
Thanks for your help in advance.
Dan Miller
16 years, 8 months
cannot retrieve timerId from timerInstance - Bug?
by tom238＠gmx.at
Hi there!
I'm using Drools 5.1.SNAPSHOT.
I want to disable some timer nodes in my ruleflow, so that they will not trigger anymore. therefore I tried the following code:
Collection<TimerInstance> tcoll = drools.getWorkingMemory().getTimerManager().getTimers();
for (TimerInstance ti : tcoll)
{
drools.getWorkingMemory().getTimerManager().cancelTimer(ti.getTimerId());
}
OK, so far so good. The code above doesn't work, because ti.getTimerId() always returns 0. Anyone an idea why this value is 0? As I've seen in the sources this field is set to an value > 0. this value is then incremented when you add another timerinstance.
Thanks in advance! hope anyone can help.
tom
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16 years, 8 months
couuld not load fact to rule engine
by Hemanth kumar
hi,
Im working on a sample test project.
In that im dynamically creating a class ( fact) and compiling it.
here is my test project
--------------------------------------------------------------------------------------
mainJavaclass
public void runRule()
{
try {
System.out.println("\nRunning rule\n");
// go !
URL[] urls = new URL[]{ new URL("file://"+path) };
URLClassLoader ucl = new URLClassLoader(urls);
Class<?> clazz = ucl.loadClass("test.Message");
Object classObj = clazz.newInstance();
Method method = clazz.getDeclaredMethod("setMessage", new
Class[]{String.class});
//System.out.println("facts loaded\n");
method.invoke(classObj, new Object[]{"Hello"});
log.info("==== Calling Rule Runner ======");
Collection facts = new ArrayList();
facts.add(classObj);
// Load and fire our rules files against the data
new RuleRunner().runStatelessRules(RULES_FILES, null, facts, null, null,
logger);
}
catch (Throwable t) {
t.printStackTrace();
}
}
----------------------------------------------------------------------
Fact
package test;
public class Message{
private String message;
public String getMessage(){
return this.message;
}
public void setMessage(String message) {
this.message = message;
}
}
------------------------------------------------------------------------
sample rule
package test
import test.Message;
rule "Your First Rule"
dialect "mvel"
when
m:Message(message != "Good Bye" )
then
System.out.println("First Rule fired "+m.message );
modify(m){ message = "Good Bye"};
end
-----------------------------------------------------------------
console file http://www.nabble.com/file/p26072723/console.PNG console.PNG
what happens is when i was running the project inside eclipse IDE it works
fine but when i hosted in tomcat and calling from outside ide the rule is
not getting fired.
I think the dyanamically loaded class is not recognised by the rule engine.
suggest me any ideas
Hemanth
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16 years, 8 months
Is there any way to hook-up Drools 4.0 RuleBase (session) to a Drools 5.0 KnowledgeBase (session) ??
by Chetan Mahadev
Hi ,
We have been using drools 4.0 in our application. All the rules are loaded
using RuleBase and PackageBuilder.
The application is pretty old, and has got lot of work into it.
Now we want to use Drools 5.0 CEP (Fusion) along with the old rules (based
on drools 4.0).
But the problem , is, how can we hook-up the old "RuleBase" based sessions
with the "KnowledgeBase" sessions of Drools 5.0??
The use case is:
1.Fact enters the system ( asserted using Rulebase), is enriched by rules
(Based on Drools 4.0)
2.The same fact will be treated as EVENT (for CEP), for further correlation
of Events (facts) using KnowledgeBase as proposed i Drools 5.0.
I am facing difficulty in hooking up the two sessions. Is there an way??
Following is the test i did. ( http://drools.pastebin.com/m7d6c613b)
Can anybody help??
IN MY JAVA CODE
1. //load up the rulebase
2. RuleBase ruleBase = readRule(); // Read and load rules frm
a packagebuilder()
3. StatefulSession rBaseSession =
ruleBase.newStatefulSession();
4. Message message = new Message();
5. message.setMessage( "Hello World" );
6. message.setStatus( Message.HELLO );
7. rBaseSession.insert( message );
8.
9. @@//Load KnoweledgeBase
10. KnowledgeBase kbase = loadRuleBase(); // I
set options for EventProcessing in loadRuleBase()
11. KnowledgeSessionConfiguration conf =
12.
KnowledgeBaseFactory.newKnowledgeSessionConfiguration();
13. ((SessionConfiguration) conf).setClockType(
ClockType.REALTIME_CLOCK );
14. StatefulKnowledgeSession kbaseSession
= kbase.newStatefulKnowledgeSession(conf,null);
15.
16. rBaseSession.fireAllRules();
17.
IN MY RULE FILE
1. rule "Hello World"
2. when
3. $m : Message( status == Message.HELLO, message :
message )
4. then
5. System.out.println( message );
6. Message message2 = new Message();
7. message2.setMessage( "Hello World" );
8. message2.setStatus( Message.HELLO );
9.
10. WorkingMemoryEntryPoint eventsignaturestream =
drools.getEntryPoint("EVENT SIGNATURE STREAM") ; // I Get a NULLPOINTER
EXCEPTION here
11. eventsignaturestream.insert(message2);
12.
13. end
16 years, 8 months
DSL, DSLR and Changesets...
by Pegram, Macon
All,
Are DSL and DSLR files supported by the KnowledgeAgent / Changeset code.
Here's the details of my test case:
I have a Changeset file I'm trying to load which looks like the
following:
<?xml version="1.0" encoding="UTF-8"?>
<change-set xmlns='http://drools.org/drools-5.0/change-set'
xmlns:xs='http://www.w3.org/2001/XMLSchema-instance' >
<add>
<resource source="classpath:com/test/general/" type="DSL" />
<resource source="classpath:com/test/general/" type="DSLR" />
</add>
</change-set>
There's a single DSL and a single DSLR file in this folder. I'm
loading the change set as follows:
KnowledgeAgent ka = KnowledgeAgentFactory.newKnowledgeAgent(agentName);
ka.applyChangeSet(ResourceFactory.newClassPathResource(agentName +
"-changeset.xml", getClass()));
When I run this code, the logger suggests the DSL and DSLR are being
loaded and compiled:
[2009:10:299 16:10:52:info] KnowledgAgent created, with configuration:
monitorChangeSetEvents=true scanResources=true scanDirectories=true
++ Constructing and applying changeSet: dsl-test
[2009:10:299 16:10:52:info] KnowledegAgent has started listening for
ChangeSet notifications
(null: 3, 68): cvc-elt.1: Cannot find the declaration of element
'change-set'.
[2009:10:299 16:10:317:info] KnowledgAgent applying ChangeSet
[2009:10:299 16:10:317:debug] KnowledgeAgent subscribing to
directory=[ClassPathResource path='com/test/general/']
[2009:10:299 16:10:317:debug] ResourceChangeNotification subscribing
listener=org.drools.agent.impl.KnowledgeAgentImpl@b9b618 to
resource=[ClassPathResource path='com/test/general/']
[2009:10:299 16:10:317:debug] ResourceChangeScanner subcribing
notifier=org.drools.io.impl.ResourceChangeNotifierImpl@61ec49 to
resource=[ClassPathResource path='com/test/general/']
[2009:10:299 16:10:317:debug] KnowledgeAgent subscribing to directory
content resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test.dsl']
[2009:10:299 16:10:317:debug] ResourceChangeNotification subscribing
listener=org.drools.agent.impl.KnowledgeAgentImpl@b9b618 to
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test.dsl']
[2009:10:299 16:10:317:debug] ResourceChangeScanner subcribing
notifier=org.drools.io.impl.ResourceChangeNotifierImpl@61ec49 to
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test.dsl']
[2009:10:299 16:10:317:debug] KnowledgeAgent subscribing to directory
content resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test-dsl.dslr']
[2009:10:299 16:10:317:debug] ResourceChangeNotification subscribing
listener=org.drools.agent.impl.KnowledgeAgentImpl@b9b618 to
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test-dsl.dslr']
[2009:10:299 16:10:317:debug] ResourceChangeScanner subcribing
notifier=org.drools.io.impl.ResourceChangeNotifierImpl@61ec49 to
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test-dsl.dslr']
[2009:10:299 16:10:317:debug] KnowledgeAgent subscribing to
directory=[ClassPathResource path='com/hmc/test/general/']
[2009:10:299 16:10:317:debug] ResourceChangeNotification subscribing
listener=org.drools.agent.impl.KnowledgeAgentImpl@b9b618 to
resource=[ClassPathResource path='com/hmc/test/general/']
[2009:10:299 16:10:317:debug] KnowledgeAgent ChangeSet requires
KnowledgeBuilder
[2009:10:299 16:10:317:debug] KnowledgeAgent rebuilding KnowledgeBase
using ChangeSet
[2009:10:299 16:10:317:debug] KnowledgeAgent building
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test.dsl']
[2009:10:299 16:10:333:debug] KnowledgeAgent building
resource=[FileResource
file='C:\bea\user_projects\workspaces\alerts\rules-kb\test-kb\target\tes
t-classes\com\test\general\test-dsl.dslr']
[2009:10:299 16:10:333:info] KnowledgeAgent new KnowledgeBase now built
and in use
However after load is completed I try to run the following code:
System.out.println("KB Info");
Collection<KnowledgePackage> pkgs =
ka.getKnowledgeBase().getKnowledgePackages();
for (KnowledgePackage kp : pkgs) {
for (Rule rule : kp.getRules()) {
System.out.println("Rule: " + rule.getName() + ", " +
ule.getPackageName());
for (String attribs : rule.listMetaAttributes())
System.out.println("---- " + attribs);
}
}
}
I get NO output (except of course "KB Info").
If I initialize the knowledgebase like this:
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory
.newKnowledgeBuilder();
kbuilder.add(ResourceFactory
.newClassPathResource("com/test/general/test.dsl"),
ResourceType.DSL);
kbuilder.add(ResourceFactory
.newClassPathResource("com/test/general/test-dsl.dslr"),
ResourceType.DSLR);
if (kbuilder.hasErrors()) {
throw new Exception(kbuilder.getErrors().toString());
}
KnowledgeBase kbase =
KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
}
... and run the same output code I get a list of the rules that were
loaded.
Any clues why the different behavior?
Macon
16 years, 8 months
Issues with groovy fact objects not matching
by Ilya Sterin
I have an application that dynamically compiles a groovy object with
properties and uses it as a bean class. The object is a statically
defined object, though...
package com.buycentives.types
import com.buycentives.incengine.*
class TestIncentive extends IncentiveData<MonetaryIncentive> {
String name
Integer age
}
The rules compile just fine, as I load the groovy class using a
GroovyClassLoader and inject the groovy class loader like this...
PackageBuilderConfiguration config = new PackageBuilderConfiguration();
config.setClassLoader(loader);
JavaDialectConfiguration dialectConf = (JavaDialectConfiguration)
config.getDialectConfiguration("java");
dialectConf.setCompiler(JavaDialectConfiguration.JANINO);
KnowledgeBuilder kBldr = KnowledgeBuilderFactory.newKnowledgeBuilder(config);
/// Here I add some rules to the builder...
KnowledgeBase kb = KnowledgeBaseFactory.newKnowledgeBase(new
RuleBaseConfiguration(loader));
kb.addKnowledgePackages(kBldr.getKnowledgePackages());
So the rule actually resolves the TestIncentive type just fine, but it
never fires the side effect, as the pattern never seems to match.
TestIncentive incentive = new TestIncentive();
incentive.setAge(25);
// Below never matches...
$input: TestIncentive( age >= 20, age < 30 )
I verify that the injected object actually has an age of 25...
The crazy thing is, that this rule...
$input: Object()
matches the TestIncentive fact in the knowledge base and when I print
out the object in the side effect, it's the same as the one injected,
so it should match the pattern above just fine.
The same rules work just fine when I use a plain Java object or if I
declare a fact type in the drl file.
Any ideas?
Ilya Sterin
16 years, 8 months
[droolsflow] - JPAKnowledgeService - Another Event based NullPointerException
by Bill Tarr
After re-loading a session, and trying to send it an Event, I get the following NullPointerException:
java.lang.NullPointerException
at org.drools.impl.StatefulKnowledgeSessionImpl$ProcessEventListenerWrapper.beforeRuleFlowNodeTriggered(StatefulKnowledgeSessionImpl.java:674)
at org.drools.event.RuleFlowEventSupport.fireBeforeRuleFlowNodeTriggered(RuleFlowEventSupport.java:147)
at org.drools.workflow.instance.impl.NodeInstanceImpl.trigger(NodeInstanceImpl.java:110)
at org.drools.workflow.instance.node.EventNodeInstance.signalEvent(EventNodeInstance.java:50)
at org.drools.workflow.instance.impl.WorkflowProcessInstanceImpl.signalEvent(WorkflowProcessInstanceImpl.java:272)
at com.csatp.svc.rulesmgr.claim.ClaimsDemoJpaTest.validateDocumentWorkflow2(ClaimsDemoJpaTest.java:209)
My code is pretty straightforward:
StatefulKnowledgeSession session = JPAKnowledgeService.loadStatefulKnowledgeSession( 1, knowledgeBase, null, env );
ProcessInstance process = session.getProcessInstance(2);
process.signalEvent("ReceiveDocsEvent", null);
that same code (and Flow) works on a session created from knowledgeBase.newStatefulKnowledgeSession();
This is difficult for me to debug, but here's what I have:
In org.drools.event.RuleFlowEventSupport.fireBeforeRuleFlowNodeTriggered(), the code is getting listeners:
final Iterator<RuleFlowEventListener> iter = getEventListenersIterator();
then iterating over them. In the session created from a regular knowledgeBase, "iter" has the following values
iter = {java.util.concurrent.CopyOnWriteArrayList$COWIterator @ 3411}
snapshot = {java.lang.Object[2] @ 3416}
[0] = {org.drools.audit.WorkingMemoryFileLogger @ 3417}
events = {java.util.ArrayList @ 3419} size = 77
fileName = {java.lang.String @ 3420}"log/claimsdemo"
maxEventsInMemory = 1000
nbOfFile = 0
split = true
initialized = false
filters = {java.util.ArrayList @ 3421} size = 0
[1] = {org.drools.impl.StatefulKnowledgeSessionImpl$ProcessEventListenerWrapper @ 3418}
listener = {com.csatp.svc.rulesmgr.claim.TrackingProcessEventListener @ 3396}
While the session created using JPAKnowledgeService has the following values for "iter"
iter = {java.util.concurrent.CopyOnWriteArrayList$COWIterator @ 3803}
snapshot = {java.lang.Object[1] @ 3805}
[0] = {org.drools.impl.StatefulKnowledgeSessionImpl$ProcessEventListenerWrapper @ 3806}
listener = null
I can see that the EventListeners should be setup in AbstractEventSupport and it's implementing classes,
and they are clearly missing, but I'm not sure where this is going wrong.
I'll gladly fix this, but just don't know where to start, if you have any ideas that can help, I'd greatly appreciate it!
Bill
16 years, 8 months
