Using the Expression Builder

ActiveBPEL® Designer User’s Guide

Using the Expression Builder

You can select among the many function types to create an expression for Copy Operations, link transitions, and other BPEL constructs. See the procedure below for details on building an expression.

Examples

Expected Expressions for Conditions, Counters, and Other Values

Example Expressions for Message, Element, and Complex Schema Type Variables

Functions

BPEL Functions

ActiveBPEL Custom Functions

See also the BPEL for People Functions in BPEL for People Online Help

Customization

Custom Functions Technical Requirements and Sample Files

Adding Custom Functions to Expression and Query Builders

Select Expression Language

For Copy Operations in the Assign activity as well as for links and other constructs, you can create XPath (or another selected language) expressions that result in a string, number, or Boolean.

For details, see the XPath 1.0 specification at http://www.w3.org/TR/xpath.

To build an expression:

Select an activity that uses expressions, such as the assign, wait, or on alarm branch of a pick activity.
In the Properties view for the activity, select the appropriate property. For example, in an assign activity, select Copy Operations, and select Expression as a Copy/From type to display the following dialog.

Expression Builder dialog

Select the variables, functions and operators from the three boxes to build an expression, following these tips:

Expand a variable to see and use the parts and properties. For detailed descriptions of variables, see Using Variables.
Double-click on a variable or variable part to paste the $variableReference function into the Expression box
Double-click on a branch under a part to paste the $variableReference function into the Expression box with path information
For working with variable attachments, see Custom Functions for Attachments.
Add your own custom functions, as described in Creating and Using Custom Functions