Configuring Exception Handling

Exceptions are designed to handle unexpected situations that arise during runtime and disrupt the normal flow of a process. Exceptions deal with the unexpected situation by executing an additional action, block or process, called an exception handler.

Some callable objects can define exceptions that are propagated to the block level and need to be processed. For that purpose, at block level, you can define an exception handler, as well as an exception handling strategy.

This tutorial demonstrates how you can model exception handling in Guided Procedures (GP).

This exemplary process consists of three steps:

1. You enter a User ID to extract details about this user.
2. In a background step, the system looks for this User ID in the UME.

   In the event of exception, that is, a user with this User ID does not exist, the system displays the input form from the first step with the User ID filled in.

3. You can view the user details in a data display form.

To be able to complete the tutorial, you need the appropriate authorizations for working with the gallery and creating components in GP design time.

More information: Authorizations

In addition, you must have implemented the User Details callable object for background execution, as described in Exposing a Java Class as a Callable Object .

To implement this tutorial, you go through the following steps:

1. Define a process flow with a background step that can return an error message.
2. Handle the error message with the exception handling mechanism.
3. Retrieve the user details data, belonging to a User ID, using the background step.
4. Activate the exception handling mechanism if the User ID is not available, so that the user can re-enter a correct User ID to continue.

You can start this tutorial by Creating a Data Input Form .