Listeners in BPMN workflows are like invisible assistants — quietly executing logic behind the scenes based on process events. In Flowable, using listeners smartly can greatly enhance your automation, tracking, and integrations.
From our hands-on experience, here are practical tips to unleash the power of listeners without complicating your BPMN models.
✅ What Are BPMN Listeners?
Listeners in Flowable are used to execute logic when certain events happen in your process, task, or execution lifecycle.
They can be added to:
-
Tasks (User Tasks, Service Tasks, etc.)
-
Events (start, end, boundary events)
-
The entire process
And they can run in:
-
Java classes
-
Expressions
-
Scripts
🔥 Top Tips to Use Listeners Like a Pro
1. Use Execution Listeners for Global Logic
Attach an execution listener to your process or activity to run logic on start/end.
🧠Use Case: Log process start, initialize variables, send notifications.
<executionListener event="start" delegateExpression="${processLogger}" />
2. Use Task Listeners for User Tasks
Task listeners are perfect for customizing behavior at the create, assignment, complete, or delete stage.
✔️ Example:
-
Send an email when a task is assigned
-
Set due dates dynamically
-
Capture audit info on completion
<taskListener event="assignment" delegateExpression="${notifyAssignee}" />
3. Keep Business Logic Outside
Instead of writing logic directly in the listener, call a Spring bean via delegateExpression.
This keeps code testable, clean, and easy to maintain.
4. Track & Audit with Listeners
Listeners are ideal for sending logs or audit events to external systems (Kafka, Elasticsearch, etc.) without cluttering BPMN diagrams.
Use them to:
-
Record who completed which task
-
Track SLA start/stop
-
Audit variable values on exit
5. Use Script Listeners with Caution
You can use inline Groovy or JavaScript scripts in listeners, but keep them simple. For complex logic, prefer a Java class or Spring bean.
Example (Groovy):
execution.setVariable("startTime", new Date())
6. Attach Listeners to Events, Not Tasks
Instead of duplicating logic across multiple tasks, attach a process-level listener to monitor the full flow.
🧠Example: A listener on end event of the process can trigger a final report generation or cleanup task.
🛠Real Tips We Apply in Flowable Projects
✅ Log process start/end in external monitoring system
✅ Notify Slack when high-priority task is assigned
✅ Automatically tag user tasks with metadata for UI
✅ Track SLA violations using due dates and complete event
✅ Capture variables before deleting sensitive tasks
🎯 Pro Tip:
Listeners + Service Tasks + DMN = Clean, Scalable Automation
Listeners let you decouple cross-cutting logic like audit, alerts, or metadata — while keeping your BPMN diagrams lean and business-focused.
Do you use listeners in your BPMN workflows? What are your favorite tricks?
#Flowable #BPMN #Automation #ProcessDesign #Listeners #WorkflowTips #LowCode #EventDriven #AKITIInstitute
0 Comments