Define an expression parameter for a step

About this task

If the processing for a step requires parameters in addition to those defined in the workflow properties, you can define expression parameters that are evaluated only for the step. After the step is completed, the value is not retained in the workflow. That means that you can use a calculated value at a step without maintaining a data field for the entire workflow.

For example, in a loan processing workflow, you could display a score calculated from a number of data fields: the applicant's salary, number of years on the job, total amount of credit payments, and so on.

To define an expression parameter for a step

  1. With the appropriate step selected, click Modify on the Parameters tab in the Properties pane.

    The Step Parameters dialog box displays all parameters for the selected step--data fields and attachments that are defined as workflow properties, and any expression parameters that are restricted to the selected step.

  2. On the Step Parameters dialog box, enter a name for the new parameter.

    NOTE  If the current workflow is inherited from another workflow definition, the list of fields includes fields inherited from the parent workflow.

    Press Tab or click outside the name field. The parameter name must conform to the standard naming conventions.

  3. Select the new name, then select the data type from the Type list—attachment, Boolean, float, and so on.
  4. Click in the Expression field and click the arrow to see the list. From the list, select <Build expression...> and enter an expression of the appropriate type.
Tip: An expression parameter can be used only within the step where it is defined—the value is not available for use outside the step, such as in a conditional routing expression. Although there is a Read/Write column, the expression parameter is read-only.
Note: If you set an expression parameter to have Read/Write access, it will return a validation error.