Capture Expression

Nodes and Palette Options > Detailed Palette Option Descriptions > Capture Expression

	Capture Expression

Type

Call Flow item

Available from

Announce Node

Prompt and Collect Node

Form Node

Menu Node

AppRoot node (see Setting Global Application Properties: AppRoot Node)

Purpose

The purpose of the Capture Expression item is to capture the value of ECMA script objects from the Voice XML page and store them in a Dialog Designer session variable.

Behavior

The Capture Expression item is used in a few different ways:

App Root - On the AppRoot, Capture Expression is used to capture ECMA script values as well as supplemental session variables when the voice dialog starts up. It can be used for capturing the value of SIP headers, for example, or other VoiceXML platform variables that are not automatically captured by Dialog Designer when a dialog starts.

Refer to the documentation for your voice portal platform for further details on headers and other variables that are exposed.

Event handlers - Capture Expression can be added to goto items used in Event handlers for capturing the event type and event message. The event type/message could then be used in another section of the callflow for handling errors differently.

Forms/Menus - Can be added to goto items on links for capturing values from the application.lastresult$ variable such as capturing the utterance that activated the link, or the ASR confidence.

Note:

Dialog Designer does not validate the ECMA script expression that is entered. It is expected that the designer has consulted the VXML specification and understand which ECMA script objects are valid at different places of the generated VXML page.

Properties

Variable - The variable that will store the captured data. Select the variable you want to use. If the variable you select is a complex variable, you must also select a Variable Field.

Variable Field - Select the variable field you want to use. The contents of this list depend on which variable you selected in the Variable property:

Expression - The ECMA script expression that will be evaluated by the VoiceXML browser. The result is stored in the variable. The ECMA script object must be simple (for example, strings or numbers).