Controlling Volume Usage with the VTA > Configuring the VTA to Run Scripts

Configuring the VTA to Run Scripts

The script runner processor can invoke external executable scripts or JavaScript programs. We recommend using JavaScript for better performance.

• External scripts are executable programs, such as shell scripts, that are available on the VTA's host. Each external script can perform a task and return a value. If the script returns a value, the value can be added to the current event as an event attribute.
• JavaScript programs are used to process attributes of a VTA event. For example, it can convert a VTA event attribute in a timestamp to a date string and add it to the event as a new attribute. The attribute can then be used for subsequent actions, such as sending an e-mail notification to the subscriber. The JavaScript program can refer to any attributes of the event being processed, and it must return a value.

To configure the script runner processor:

1. Configure a JavaScript program or an external script. See:

• Configuring JavaScript Programs
• Configuring External Scripts

2. Configure an action for the script runner processor. See:

• Configuring VTA Actions to Run Scripts

Configuring JavaScript Programs

To configure a JavaScript program:

1. In VTA Configuration Manager, select Edit or Create in the navigation pane.

The Current Configuration window appears.

2. Select Processors.
3. Select Script Runner Processor.

The Script Runner Processor configuration appears.

4. If the Script Runner processor is disabled, click Enable to enable it.
5. Enter the name of the script in the New Javascript field, and click Create.

The JavaScript configuration appears.

6. Fill in the fields for the JavaScript. See JavaScript Fields.
7. Configure a VTA action for the script. See Configuring VTA Actions to Run Scripts.

JavaScript Fields

This section describes the fields used to configure JavaScript programs.

New Javascript

• Name of the JavaScript program.
• Value—Text string
• Default—No value

Javascript

• A function body in JavaScript.
• Value—Path name. To refer to the event attributes being processed, include the attribute name delimited by angle brackets (<and>). The JavaScript can verify if the event has the referred attribute. If a referred attribute does not exist in the event, the attribute's value is null. The JavaScript must return a value.
• Default—No value

Parameter

• Parameters required by the script. When invoking the script from an action, the action must supply values for these parameters.
• Value—Comma-separated list of parameters
• Default—No value
• Example—fullLoginName

Return Attribute

• Attribute that provides the return value of the script as a valid Java identifier that subsequent actions and event handlers can refer to.
• Guidelines—JavaScripts must return an attribute value. The name of a return attribute cannot start with an underscore (_) because these event attributes are reserved for internal use.
• Value—Attribute name
• Default—No value

Return Type

• Java type of the return attribute.
• Value

• Integer
• Long
• Float
• Double
• String
• Boolean

Configuring External Scripts

To configure an external script:

1. In VTA Configuration Manager, select Edit or Create in the navigation pane.

The Current Configuration window appears.

2. Select Processors.
3. Select Script Runner Processor.

The Script Runner Processor configuration appears.

4. If the Script Runner processor is disabled, click Enable to enable it.
5. Enter the name of the script in the New External Script field, and click Create.

The External Script configuration appears.

6. Fill in the fields for the external script. See External Script Fields.
7. Configure a VTA action for the script. See Configuring VTA Actions to Run Scripts.

External Script Fields

This section describes the fields used to configure external scripts.

New External Script

• Name of the external script.
• Value—Text string
• Default—No value

Full Path

• Full pathname of the external script.
• Value—Pathname
• Default—No value

Parameter

• Parameters required by the script. When an action invokes the script, the action must supply values for these parameters.
• Value—Comma-separated list of parameters
• Guidelines—External scripts require parameters
• Default—No value
• Example—fullLoginName

Return Attribute

• Attribute that provides the return value of the script as a valid Java identifier that subsequent actions and event handlers can refer to. If this attribute is not set, the return value is not used by the event. The external script returns the value by printing to standard output.
• Value—Attribute
• Guidelines—The name of a return attribute cannot start with an underscore (_) because these event attributes are reserved for internal use.
• Default—No value

Return Type

• Java type of the return attribute.
• Value

• Integer
• Long
• Float
• Double
• String
• Boolean

• Default—No value

Configuring VTA Actions to Run Scripts

You can configure actions that the script runner processor performs on events. For example, you can set up an action to run either an external script or a JavaScript program.

To configure actions for the script runner processor:

1. In the VTA Configuration Manager navigation pane, select Edit.
2. Under Current Configuration, click Actions.

A list of actions appears. For example:

3. To add an action, enter a name for the action in the New Quota VTA Actions field, and click Create.

The action configuration screen appears.

4. Select ScriptRunner in the Processor field, and click Save. (If ScriptRunner does not appear in the pull-down list, enable the Script Runner Processor.)

An expanded configuration screen for the action appears.

5. Fill in the fields described in this section.

Processor

• Processor for which you are configuring the action.
• Value—ScriptRunner (If ScriptRunner does not appear in the drop-down list, enable the Script Runner Processor.)
• Default—No value

Function

• Function calls that the script runner processor invokes.
• Value

• ExecExtScript—Runs an external script defined in the processor. It provides any defined ReturnAttribute attribute for the corresponding script as output by adding the attribute to the event.
• ExecJavaScript—Runs a JavaScript defined in the processor. It provides any defined ReturnAttribute attribute for the corresponding script as output by adding the attribute to the event.

• Default—No value

Parameter Name

• Parameters to pass to the processor.
• Value

• For external scripts:

• scriptName—Name of the script
• Parameters that you declared in the script

• For JavaScripts:

• scriptName—Name of the script

Parameter Content

• Parameter values to pass to the processor.
• Value

• For scriptName parameters—Name of the script
• For other parameters—Values of parameters that you declared in the script

Abort On Error

• Disables or enables and sets the processing in response to an error.
• Value

• Break—Stop processing the current event.
• Continue—Continue with the next action, if any, in the same event handler.
• Next Event Handler—Continue with the next event handler (if any).

• Default—No value