NET/MASTER Network Control Language (NCL) Reference Manual

6 Panel Control Statements
106126 Tandem Computers Incorporated 6–1
Using panel control statements, you can control panel displays by creating and
modifying panel description files. (You can use the Tandem text editor, TEDIT,
available in NonStop NET/MASTER MS Edit Services, to create panel description
files.) Once displayed, panels allow you to enter data. Panel control statements are
not part of the displayed screen.
To summarize the connection between a panel description file and a panel display:
A panel is displayed when you invoke it with the NCL PANEL verb.
When you enter data into a panel, the data is available to the invoking NCL
procedure through the variables you specify in the panel description file.
You can use panel control statements to design the panel layout.
You can use the #INCLUDE panel statement to copy panel control statements
from one panel description file to another. This simplifies the work of developing
new panels.
Panel control statements also allow you to describe how the panel is displayed and
to define the fields that are available for data entry. All the characteristics of the
terminal that displays the panel—such as alarm sounding, intensity of the
displayed data, reverse video, blinking, and so on—are available to you through
these panel control statements.
Panel control statements can affect the style, content, and nature of user input. For
example, you can edit and validate input fields to minimize the processing that
might otherwise be required within NCL procedures that receive the input data.
In addition, you can use panel control statements to define how to handle errors.
Panel control statements are always prefixed by a pound sign character (#). The
pound sign distinguishes a panel control statement from the displayable panel
content.
Panel control statements, called the control part, form the first part of a panel
description file, and are followed by the panel (screen) content. The first line that is
not a control statement determines the start of the display part of the panel. You must
group all panel control statements together at the beginning of a panel description file;
otherwise, the statements may become part of the displayable panel.
Panel description files must reside in a panel library. NCL recognizes three panel
libraries. To improve efficiency and to avoid unnecessary library searches for
frequently used panels, panel description files can be made resident in memory. See
the PANEL verb in Section 3, “Verbs,” for more information on panel libraries and on
preloading panel description files.