Callable Object 

Definition

A reusable unit that enables the execution of external applications or services within the Guided Procedures (GP) framework.

Callable objects are the most fine-grained elements in a process.

Use

Using the Guided Procedures design-time functions, you can create various types of callable object that execute applications, such as:

·        Web Dynpro applications and services

·        BSP applications

·        Remote-enabled function modules

·        Java classes, and so on.

To execute a callable object in a GP process, you must attach it to an action, which is then integrated into a block.

More information: Process Modeling

Structure

A callable object is defined by the following parameters:

●      Input and output parameters

You can implement a callable object, so that it retrieves input data from a user or from another object. You do this by creating input parameters of the relevant type.

To enable a callable object to provide data as a result of its execution, you define output parameters. At runtime, you can map them to the appropriate input parameters of another object, thereby enabling data flow throughout the process.

More information: Callable Object Parameters

●      Configuration parameters

You can also make the callable object configurable by defining configuration parameters for it. These are defined programmatically in the implementation of the function that is exposed as a callable object. At design time you can set the appropriate values for these parameters.

For example, if you implement a function that sends an e-mail, you can define the e-mail template and the recipient as configuration parameters, and set them up when instantiating the callable object using the GP design time.

●      Result states

The result states of a callable object indicate the outcome of its execution. In addition, they enable you to manage the process flow in a flexible way, by defining different workflows depending on the state reached.

You define and set the result states in the implementation of the callable object. At design time, you can configure a target action for each defined result state.

●      Exception handling

You can implement your callable object so that it defines process exceptions.

You can implement callable objects with user interfaces, such as Web Dynpo or BSP applications. The GP framework also provides APIs for callable objects that are executed in background mode, and do not necessarily provide UIs.

More Information

Exposing Applications as Callable Objects

Implementing Additional Callable Objects