Variable Listener Boundary Event

Introduction

The variable listener allows to listen to the creation or modification of a variable. The boundary event can be attached to any other activity in the BPMN diagram and will be active during the activity is active. The boundary event can be either interrupting or none interrupting.

Properties

General

Attribute	Type	Description	Category
Model Id	Text	Model Id identifies the element within the process model.	The model id, name and documentation properties can be found on any element. They are used respectively to uniquely identify the boundary event, to give it a user-friendly name and to add a free-form description.
Name	Text	The name of the element. This is the name displayed in the diagram.
Documentation	Multiline Text	A free-form text that can be used to explain details about the particular element.
Variable name	Text	The variable name for which the variable listener will listen for changes.	Configure which variable changes should trigger the boundary event and which type of change is listened to. By default, triggering the boundary event will cancel the activity it is attached to. To change this, uncheck the 'Cancel Activity' checkbox. A new flow of execution starting from the boundary event will be started concurrently.
Change type	Selection: All Create only Update only Create and update	Defines for which variable value changes the variable listener will be triggered.
Cancel activity	Boolean	Denotes whether the activity should be canceled or not, i.e., whether the boundary catch event will complete the activity it is attached to.

Advanced

Attribute	Type	Description	Category
Execution listeners	List	Allows invoking custom after certain lifecycle events. Start: Executes after the activity has been started. End: Executes after the activity was completed. Transition: When defined on a sequence flow, executes once the flow is transition is taken.	Execution listeners are used to add logic on certain lifecycle events. Typically it is used to add extra technical logic which shouldn't be visible in the BPMN process model.

Visual

Attribute	Type	Description	Category
Font size	Selection: 8 9 10 11 12 14 18 20 24 36 48 72	Font size.	Visual properties that determine how the boundary event is shown in the diagram. This has no impact on the runtime execution.
Font weight	Selection: Normal Bold	Select the style between bold and normal.
Border color	Color	The border color of the element in the diagram.
Font style	Selection: Normal Italic	Select the style between italic and normal.
Font color	Color	Select a font color.
Background color	Color	The background color of the element in the diagram.

List Attribute Details

Execution listeners

Attribute	Type	Description
Event	Selection: Start End Take	The lifecycle event. The 'Take' event is only available for sequence flow.
Class	Text	Fully qualified classname of a class to be invoked when executing the task. The class must implement either JavaDelegate or ActivityBehavior.
Expression	Text	JUEL Expression to be executed when the task is started. Expressions allow you to interact with the backend by calling services, making calculations etc. You can find more information about expressions in the documentation.
Delegate expression	Text	Delegate Expression to be executed when the task is started. A delegate expression must resolve to a Java object, for instance a Spring bean. The object's class must implement either JavaDelegate or ActivityBehavior.
Fields	List

Fields

Attribute	Type	Description
Name	Text	The name of the element. This is the name displayed in the diagram.
String value	Text
Expression	Text	JUEL Expression to be executed when the task is started. Expressions allow you to interact with the backend by calling services, making calculations etc. You can find more information about expressions in the documentation.
String	Text