Assign activity

Chapter 17 Working with WS-BPEL 2.0

Assign activity

The assign activity is used to update the values of variables with new data. An <assign> element can contain any number of elementary assignments, including <copy> assign elements (copy from-to).

Syntax

<copy>

</copy>

<copy>

</copy>

</assign>

Mapping

You design an assign activity in any of the following ways:

Select the "Assign" implementation type in a process property sheet
Right-click an <<empty>> process or a process without any stereotype and select the Change to Assign command

This type of activity triggers the display of the Assignments tab:

In the Assignments tab you then have to:

Click a blank line to create a data transformation object.
Select an Assigned Variable to define the target property of the assign task.
Select an Input Variable to define the source property of the elementary assign task.

Extended attributes

The following extended attribute applies to the assign activity and is available from the WSBPEL tab in its property sheet:

Name	Internal code	Description
—	expressionLanguage	Specifies the expression language used in expressions
—	Validate	When the value of this attribute is set to "yes", the assign activity validates all the variables being modified by the activity
Multiple Correlation	MultipleCorrelation	Defines BPEL Invoke, Receive or Reply activities using several correlations.
Join Condition	joinCondition	Join condition
Suppress Join Failure	suppressJoinFailure	Avoids propagation of Join Failure exceptions

Implicit assignments

WS-BPEL 2.0 defines the concept of implicit assignments under messaging activities, such as Receive, Reply, Invoke, ReplyFault, OnMessage and OnEvent. An Assignments tab is automatically displayed in the property sheet of these activities when the "Support Implicit Assignment" setting is set to true in the process languages supporting these types of activities.