Define an External Action Block

Implementing External Action Blocks › Design › Define an External Action Block

Define an External Action Block

An External Action Block is defined using the Action Diagramming tool, which is part of the Design Toolset on the workstation. An External Action Block is an action block that comprises up to three components:

Import Views (optional)
Export Views (optional)
EXTERNAL statement

Note: An External Action Block contains no action statements or action diagram logic of its own. The action block only contains the EXTERNAL statement.

The EXTERNAL designation tells CA Gen that a program generated outside of CA Gen provides the data for the External Action Block's export views. The procedure step or action block that uses the External Action Block supplies the import view data. The following figure is an example of an action diagram that defines the External Action Block READ_HISTORY.

Action Block:_READ HISTORY
    READ HISTORY
        IMPORTS:  Entity View new customer
        EXPORTS:  Entity View current customer
    EXTERNAL

The import views define the data passed from the application generated through CA Gen to the External Action Block. The export views define the data returned to the application generated through CA Gen from the External Action Block.

The External Action Block must be properly defined for CA Gen to generate the code for the procedure step or action block that uses the External Action Block. Code generation does not automatically generate the code for the External Action Block, although you use the code generation tools to generate a stub for the External Action Block.