How to get business rule task implemetation type from DelegateExecution

Camunda 7 Topics Discussion & Questions
1

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I need attribute of BusinessRuleTask#implementation to do something in my global listener, i try to get it like below way but failed.

DelegateExecution execution = xxx;
ActivityExecution activityExecution = (ActivityExecution) execution;

FlowElement bpmnModelElementInstance = execution.getBpmnModelElementInstance();
ModelElementInstance documentElement = execution.getBpmnModelInstance().getDocumentElement();

// below result is '#unspecifed'
String implementation = bpmnModelElementInstance.getAttributeValue("implementation");

PvmActivity activity = activityExecution.getActivity();
Object property = activity.getProperty(BpmnProperties.TYPE.getName());
if (!Objects.isNull(property) && ActivityTypes.TASK_BUSINESS_RULE.equalsIgnoreCase(property.toString())) {
	// do something..
}

I find type hierarchy with org.camunda.bpm.model.xml.instance.ModelElementInstance below.

ModelElementInstance → InteractionNode → Activity → Task → BusinessRuleTask

What can i do? Tell me please.
Thank you very much.

2

Hi @Burn,

Did you try below

FlowElement bpmnModelElementInstance = execution.getBpmnModelElementInstance();
if (bpmnModelElementInstance instanceof BusinessRuleTask) {
	BusinessRuleTask brt = (BusinessRuleTask) bpmnModelElementInstance;
	String impl = brt.getImplementation();
}
3

Thank for your reply, unfortunately i try that get same result(’##unspecified’) as above code, may be Camunda extended occur after BPMN doc render, i will try other way until find answer.

5

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As you can see, It doesn’t work！
Thanks again for your reply anyway.

6

Hi @Burn,

I found the reason for that

If you have a look at the XML view of your model, you would find that no implementation attribute at all but there is camunda:decisionRef attribute

<bpmn:businessRuleTask id="Task_18ufkc9" name="Task 1" camunda:decisionRef="DR01">
	<bpmn:extensionElements>
		<camunda:executionListener class="com.ap.testapp.RTListener" event="end" />
	</bpmn:extensionElements>
	<bpmn:incoming>SequenceFlow_0xqa8he</bpmn:incoming>
	<bpmn:outgoing>SequenceFlow_0y6as71</bpmn:outgoing>
</bpmn:businessRuleTask>

Because of that if you try below code

public void notify(DelegateExecution execution) throws Exception {
		
	FlowElement bpmnModelElementInstance = execution.getBpmnModelElementInstance();
	if (bpmnModelElementInstance instanceof BusinessRuleTask) {
		BusinessRuleTask brt = (BusinessRuleTask) bpmnModelElementInstance;
		String decisionRef = brt.getCamundaDecisionRef();
		
		System.out.println("decisionRef: " + decisionRef);
		
		String impl = brt.getImplementation();
		
		System.out.println("impl: " + impl);
	}
}

You will get a value for decisionRef but nothing for impl

decisionRef: DR01
impl: ##unspecified

7

For that exact reason I have implemented a scanner that allows to retrieve said information.
You can check the following lines of code here. Maybe you can use that as starting point, because there are several cases where the API does not return the proper values and thus I extracted the needed values directly from the BPMN.

Best regards
Sascha

1 Like
8

You are right, i realized decision structure that exist ‘camunda:decisionRef’ not ‘implementation’ attribute but i not found some api(BusinessRuleTask#getCamundaDecisionRef) between camunda and bpmn element

I should really try more so I don’t waste your time, i’m sorry.

Thanks.

9

Thank you very much.

If it wasn’t @ hassang answer, I would have parsed the XML to get the value as your suggest.

10