Siebel Business Process Framework: Task UI Guide > Task UI Concepts > Language Concepts for Task UI >
Task event handlers allow you to configure the processing that occurs when Pause, Resume, Pre-Cancel, or Delete events are triggered by the end user. You can add event handlers to your task using the Task Designer in Siebel Tools. To configure a task flow for event handling, you must create a Task Event object under the parent Task object, and specify a business service or a service workflow to call when the corresponding task event occurs.
Task events can be triggered by the following end-user operations:
- Resume. Reinstantiates a task instance by restoring the task's state and history. This event resumes a paused task when the owner clicks an inbox item of the type Task in the inbox view.
- Pause. Causes the task state and the history stack to be serialized and stored on the disk. An inbox item, which may be used to resume the task, is created in the inbox on the disk.
- Cancel. Either deletes the task or rolls it back to its prior state. If the task has a parent flow, the parent flow receives an Abort status from the task.
- Delete. Removes the task from the inbox, and removes the task instance from the database. If the task is initiated by its parent workflow process, the parent flow receives an Abort status from the task. This event is created by the task utility service.
The event handlers are executed before the Resume, Pause, Cancel, or Delete end-user operation is carried out. Therefore, the event handlers are considered pre-event handlers. If the event handler execution succeeds, the task controller proceeds to complete the end-user operation. If an error occurs during event handler execution, the end-user operation is halted. Errors that occur during event handler execution are returned to the end-user. For information on how to configure event handlers, see Configuring Task Event Handlers.