ENABLE User's Guide

CREATING AND RUNNING A MULTIFILE APPLICATION
Associating and Linking Boxes
Although you can supply values for other box attributes when you
describe and add a box, this discussion assumes that the default
values suit your needs. If you use the SET command to describe a
box, you might want to use the RESET BOX command (to reset the
attributes to their starting values) before you describe and add
the next box. After you describe and add the necessary boxes,
you are ready to associate the boxes with an application.
Associating and Linking Boxes
When you generate a multifile application, you must identify:
• The boxes to be used by the application
• The logical connections or links that exist between the boxes
• The order in which the boxes are to be connected for the
application
To perform this task, supply a value for the TREE application
attribute. When you supply a value for this attribute, you build
a logical structure called a tree structure that ENABLE uses to
organize the application.
What Is a Tree Structure?
A tree is a hierarchical structure similar to a family tree.
Within the tree structure, each box has a specific position, much
as you have a specific position within your own family. The
position of a box within a tree structure is called its level. A
box at one level of the tree structure is connected to a box (or
boxes) at other levels of the tree structure by links. Figure
5-5 illustrates a sample two-level tree structure and shows the
value of the TREE attribute that builds this structure.
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