Designing the Procedure Logic › External Action Blocks

External Action Blocks

You may need to use logic that was not defined using CA Gen. You can do this by using an external action block.

Use an external action block to do the following tasks:

• Bridge to an existing system
• Read from or write to an ASCII file
• Construct and print reports
• Perform database functions not supported by CA Gen
• Perform other C functions such as CA Gen assigns a small integer (8 bits) for number set to 1 position.
• If more granular typing (domain assignment) is required, an external action block can be used.

An external action block has only three components:

• Import views
• Export views
• External designation

An external action block contains no action statements of its own.

The designation external on the action block definition indicates that a non-CA Gen-generated program will be used to obtain the data for the action block's export view. This type of action block can be the object of a USE statement in normal Procedure Action Diagrams or Blocks.

During construction, CA Gen ensures that the program referenced by the external action block is properly referenced by CA Gen-generated programs.

The next sample code illustrates a CA Gen-defined Procedure Action Diagram that references an external date manipulation routine called Date Services.