# Register Execution Listener via BpmnParseHandler

**URL:** <https://forum.flowable.org/t/register-execution-listener-via-bpmnparsehandler/11395>\
**Category:** Flowable Engine\
**Created:** [April 2, 2024, 7:44pm UTC](https://forum.flowable.org/t/register-execution-listener-via-bpmnparsehandler/11395 "2024-04-02T19:44:30Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![chaserb](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.flowable.org/chaserb/32/3084_2.png) [@chaserb](https://forum.flowable.org/u/chaserb)\
**Post date:** [April 2, 2024, 7:44pm UTC](https://forum.flowable.org/t/register-execution-listener-via-bpmnparsehandler/11395/1 "2024-04-02T19:44:30Z")

</div>

Hello,

I’m attempting to register execution listeners on my BPMN assets to achieve an aspect-oriented approach to implementing global behavior without globally modifying my library of BPMN XML. I was thrilled to find an approach for this in the [Open Source Documentation](https://www.flowable.com/open-source/docs/bpmn/ch18-Advanced/#hooking-into-process-parsing). Unfortunately, the execution listeners I register via the BpmnParseHandler are never triggered. If I instead manually create the execution listeners with `<extensionElements>` coded directly into the XML, then my listeners behave as expected.

I’ve put together a [reproducible test](https://github.com/chaserb/bpmn-parser-test) that isolates the problem I’m seeing. If you take a look at the two screenshots in the project’s README, it’s clear that the BpmnParseHandler successfully registers extension elements that identify my listener class in the in-memory BPMN models, but those extensions do not translate into listener instances in the `Process.getExecutionListeners()` list (for instance).

I’ve searched this forum for mention of a similar problem, but the [only post I’ve found](https://forum.flowable.org/t/migrate-to-flowable-from-activiti-bpmparsehandler/8449) with “BpmnParse” in the title is currently unanswered.

The problem seems to be that my BpmnParseHandler is adding the extension elements too late in the parsing process. By the time `BpmnParse.execute()` calls `BpmnParse.applyParseHandlers()`, the `BpmnXMLConverter.convertToBpmnModel()` call has already translated extension elements to execution listeners, and so my dynamic XML addendums go unrecognized.

Am I on the right track for registering dynamic execution listeners, or am I missing the point?

Best Regards,  
Chase

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<div class="post-metadata">

**Author:** ![filiphr](https://yyz1.discourse-cdn.com/flex035/user_avatar/forum.flowable.org/filiphr/32/315_2.png) [@filiphr](https://forum.flowable.org/u/filiphr)\
**Post date:** [June 12, 2024, 9:27am UTC](https://forum.flowable.org/t/register-execution-listener-via-bpmnparsehandler/11395/2 "2024-06-12T09:27:54Z")

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Hey @chaserb,

The problem is that you are adding an extension element instead of a listener. What you need to do is something like:

```java
public class CustomPreParseHandler implements BpmnParseHandler {

    private final FlowableListener startListener;
    private final FlowableListener endListener;

    public CustomPreParseHandler() {
        startListener = new FlowableListener();
        startListener.setEvent(ExecutionListener.EVENTNAME_START);
        startListener.setImplementationType(ImplementationType.IMPLEMENTATION_TYPE_CLASS);
        startListener.setImplementation("test.bpmn_parser.CustomExecutionListener");

        endListener = new FlowableListener();
        endListener.setEvent(ExecutionListener.EVENTNAME_END);
        endListener.setImplementationType(ImplementationType.IMPLEMENTATION_TYPE_CLASS);
        endListener.setImplementation("test.bpmn_parser.CustomExecutionListener");
    }

    @Override
    public Collection<Class<? extends BaseElement>> getHandledTypes() {
        return List.of(Process.class, ScriptTask.class);
    }

    @Override
    public void parse(final BpmnParse bpmnParse, final BaseElement element) {
        if (element instanceof Process process) {
            process.getExecutionListeners().add(startListener);
        } else if (element instanceof FlowElement flowElement) {
            flowElement.getExecutionListeners().add(endListener);
        }
    }

}

```

Cheers,  
Filip