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11. Jun 2009, 01:19 America/New_York | Link |
We added a couple of new features to the seam-drools integration:
1. Support for Decision Tables (JBSEAM-4188):
<drools:rule-base name="ruleBase" rule-files="myDecisionTable.xls"/>
You can now compile rules from your Decision Table (xls) when using the drools:rule-base component in components.xml
2. Support for Drools Custom Consequence Exception Handlers (JBSEAM-4049):
<drools:rule-base name="ruleBase" rule-files="myDecisionTable.xls" consequence-exception-handler="#{myConsequenceExceptionHandler}"/>
You can use the new consequence-exception-handler attribute to add a new exception handler. This exception handler can be a Seam component and can look like:
Scope(ScopeType.APPLICATION)
@Startup
@Name("myConsequenceExceptionHandler")
public class MyConsequenceExceptionHandler implements ConsequenceExceptionHandler, Externalizable {
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
}
public void writeExternal(ObjectOutput out) throws IOException {
}
public void handleException(Activation activation,
WorkingMemory workingMemory,
Exception exception) {
throw new ConsequenceException( exception,
activation.getRule() );
}
}
3. Support for Drools Event Listeners (JBSEAM-4225):
<drools:managed-working-memory name="workingMemory" rule-base="#{ruleBase}">
<drools:event-listeners>
<value>org.drools.event.DebugWorkingMemoryEventListener</value>
<value>org.drools.event.DebugAgendaEventListener</value>
</drools:event-listeners>
</drools:managed-working-memory>
This allows you to be notified of rule engine events, including rules firing, objects being asserted, etc by simply adding the drools:event-listeners element to your managed-working-memory component in components.xml as shown in the example
These updates will be available in 2.2.0.CR1. We are also working on adding RuleFlow support in the near future.
Tags: drools
I believe this link to thread in the rule-dev mail list gives further information about Seam / Drools integration and offers a way to send comments and suggestions on this subject (JBSEAM-4260):
http://lists.jboss.org/pipermail/rules-dev/2009-August/001414.htmlHi, could you please help me,
i try to inject the working memory in the Seam component
@In
WorkingMemory decisionWM
but when i run the server, i got error.
Please help me. thank you
Hello Mas,
What is the Seam version used? Post your entire error and your components.xml so we can try to help.
Thanks.
Sorry for my late reply. Ok, this is my scenario. I am using seam 2.1.2. I create a process in my project, in the first node, the process will call some data from the dB, pass the data to the second node. In the second node, i want to evaluate the data using Drools. This is a part of my processDefinition.xml;
....
<node name="Collect Data">
<event type="node-enter">
<action expression="#{notifyPatient.notification}"/>
</event>
<transition to="Evaluate Data"></transition>
</node>
<node name="Evaluate Data">
<event type="node-enter">
<action expression="#{evaluateData.evaluatStatus}"/>
</event>
<transition to="Send Email"></transition>
</node>
.....
I'm having trouble in the EvaluateData, in this seam component, i want to inject the workingMemory like the code below;
@Name("evaluateData")
public class EvaluateData {
@In WorkingMemory evaluationRulesWorkingMemory;
@In Status status;
@In Result result;
public void evaluateStatus() throws FactException
{
policyPricingWorkingMemory.insert(status);
policyPricingWorkingMemory.fireAllRules();
}
....
The error is at the @In WorkingMemory..where it will create a null value, and will create error in the JBPM context. The error will also occur if i define the workingmemory directly in processDefinition. I do not have problem injecting the data that i pass from the previous node. And the output from the .drl file is a just strings.
This is my Drools part in the component.xml;
...
<component name="evaluationRule"
class="org.jboss.seam.drools.RuleBase">
<property name="ruleFiles">evaluation.drl</property>
</component>
<component name="evaluationRulesWorkingMemory"
class="org.jboss.seam.drools.ManagedWorkingMemory" auto-create="true">
<property name="ruleBase">"#{evaluationRules}"</property>
</component>
.........
Another question is, where should i put my .drl file? Currently, i put it in the EAR folder.
Thank you for your time.