About Worklist Manager Tasks

Worklist Manager tasks are defined and configured by a task definition file. A task is exposed as a web service operation by the WLM SE, and request and reply web service operations are defined for each task in the project's WSDL file. The input message of this operation is the task input and the output message of the operation is the task output.

The following topics provide information about the structure of the files that define a task and about the supported features of Worklist Manager tasks:

• Task Definition File

• Task Definition Schema

• XPath Expressions in Task Definitions

• Automatic email Notifications

• Changing Variables

• Task Escalations and Timeouts

Task Definition File

When you define a task using the Task Definition Wizard, the wizard generates a new task definition file, which has a “.wf” extension in the WLM project. The task definition file is in XML format, and can be edited through the Task Definition Editor or by editing the XML text directly. A task generally has an input from the BPEL process, and upon completion generates output back to the BPEL process for continued processing.

The task definition file specifies the following information:

• A title and priority for the tasks.

• The users and groups which the tasks are assigned.

• Keywords by which users can search on the Worklist Manager Console for tasks.

• Durations or deadlines by which a task must be completed before it is escalated to the specified users or groups.

• Durations or deadlines by which a task will time out if it is not completed.

• Email or other types of notifications that are sent out when certain events occurs, such as a task being created, completed, or escalated.

• Default values for task output fields (implemented as variable initializations).

• Variable updates that are made when a task status changes, such as inserting the timestamp in a date field when a task is completed.

Task Definition Schema

The XML schema file for the Worklist Module project defines the structure of the data that will be sent to and output by the worklist task. It is referenced from the messages element of the WSDL file, and its namespace prefix is used in the XPath expressions in the task definition file.

XPath Expressions in Task Definitions

The task definition file supports XPath expressions to help define the properties for each task. You can use XPath expressions in task definitions to define literal values for task properties and to define variables whose values are dynamically derived from the input data. You can also use XPath functions to manipulate data and define how data is processed. A mapper is available on the Actions tab of the Task Definition Editor to automatically generate the XPath syntax for the actions you define. For basic properties, escalations, and notifications, you can enter XPath expressions directly into the fields on the Task Definition Editor or directly into the source code.

The Task Definition Editor supports the XPath 1.0 specification in Design view. The Source view also supports XPath 2.0 expressions, which allows you to define if-then-else conditions. To use XPath expressions to retrieve data from the task input, you need to register a prefix for the XML schema file namespace in the task definition file. Once you do this, you will use the prefix in the actual XPath expressions. You can manipulate input and output data using the WLM variables: $TaskInput and $TaskOutput. For example, an expression that extracts information about the price of an item might look similar to the following:

$TaskInput:part1/ns1:price where 'ns1' is the namespace prefix you defined.

Automatic email Notifications

You can configure a task to automatically generate notifications to certain users or groups of users when a certain action occurs. The WLM SE can send notifications via email when a task's status changes, or when an escalation or task timeout occurs. The Email BC is used to send the notifications. For example, when a task is assigned to a user or group of users, an email can be sent to each user to inform them that the task is ready to be worked on. Then, when the task is completed, another notification can be sent to the user's manager letting them know it is done. You can also define custom notifications that do not use email, but instead invoke a web service, for example.

When you create notifications in the task definition file, a WSDL file named EmailNotificationHandler.wsdl is automatically generated to handle the notifications. This file will require some customization to match your email server settings.

Changing Variables

When a task is being processed, you might want certain actions to change the value of an output variable. For example, you might want to insert the current date and time into the output message when a task is completed. The Task Definition Editor supports mapping literal values or values from input messages to the output variables using XPath 1.0 expressions.

Task Escalations and Timeouts

You can manage the task handling process by defining automatic escalations and timeout periods for each task. A task escalation can assign a task to another user, such as a manager, when the task is not completed within the specified time period. This ensures that a process is not held up because a human workflow task is not completed. Tasks can be escalated based on a duration or on a deadline.

A task timeout defines a deadline or duration after which a task fails. If you define a task timeout and the task is not completed within the specified duration or by the specified deadline, the task is treated as failed and returns to the workflow (BPEL process) with a system fault. This is useful for cases when a task is not completed even after it has been escalated.