NET/MASTER Network Control Language (NCL) Programmer's Guide

Obtaining Input From a Panel
Working With Panels
106160 Tandem Computers Incorporated 14–67
Table 14-10 lists the operands you can use to control the mapping of function keys on
an IBM 3270 or compatible terminal.
Table 14-10. Processing Program Function (PF) Keys
Operand Description
PFKMAP Enables mapping of upper-row function keys (PF13 through PF24) to lower-row
function keys (PF01 through PF12). The system variable &SYS.INKEY contains a
value from PF01 through PF12. When using this option, the NCL procedure must
intercept and process function keys PF01 through PF12, but can ignore function
keys PF13 through PF24.
NOPFKMAP Disables mapping of upper-row function keys (PF13 through PF24) to lower-row
function keys (PF01 through PF12). The system variable &SYS.INKEY contains a
value from PF01 through PF24. When using this option, the NCL procedure must
intercept and process function keys PF01 through PF24.
Processing IBM 3270 or Compatible Terminal Program Attention (PA) Keys
When using an IBM 3270 or compatible terminal, the CONTROL verb allows to you
control the processing of program attention (PA) keys. Table 14-11 lists the operands
you can use to control the processing of PA keys.
Table 14-11. Processing Program Attention (PA) Keys
Operand Description
PAKEYS Allows the NCL procedure to process program attention (PA) keys.
NOPAKEYS Disallows the NCL procedure from processing program attention (PA) keys.
Handling Internal Validation
Errors
If a validation error is detected, an NCL process must be able to notify you about the
field in error and the nature of the error. Errors can be identified by a four-step
process:
1. Take advantage of the variable substitution performed for panel control
statements.
2. Set appropriate variables for the #OPT control statement using the CURSOR and
ALARM operands.
3. Move suitable text into an error message variable.
4. Redisplay the panel.
This technique works well, but places additional responsibility on your NCL
procedure to ensure correct variables are set and cleared later if no errors are detected.
(The situation is compounded as the number of fields on the panel increases.)
You can assist the user of a panel in identifying errors, if you highlight those fields in
error. You can do so by switching them to another color or by using facilities such as
blinking or reverse video on terminals that support these facilities. This can also be