CFnn (Command Function) keyword for display files

Use this file- or record-level keyword to specify that the function key specified in the keyword (CF01 through CF24) is available for use.

It is to be used as a command function (CF) key to transmit changed data as opposed to a command attention (CA) key, which does not transmit changed data. Response indicators 01 through 99 are valid.

See the System/36 environment considerations for display files topic for special considerations when you specify the CFnn keyword in files that are used in the System/36™ environment.

The format of the keyword is:

CFnn[(response-indicator ['text'])]

If you specify this keyword, and the display station user presses the specified function key, the following situation happens:

All other function key response indicators in the input buffer are set off (hex F0).
The response indicator, if specified with the CFnn keyword, is set on (hex F1).
The i5/OS™ data management feedback area is updated.
Data is placed in the input buffer according to data received from the device.
Control is returned to your program.

If you specify a response indicator and the key is pressed, the response indicator is set on and returned to your program along with the input data. If no response indicator is specified, the input data is returned to your program. (The text information is associated with the indicator and is used by high-level language compilers to help in program documentation.)

If the display station user presses a function key and you have not specified it as either a CF key or a CA key, the i5/OS operating system displays a message to the display station user indicating that the key is not valid at that time.

You can use combinations of CF and CA keywords within the same display file, but you cannot specify the same key number as both command attention and command function. For example, CA01 and CF01 are not valid in the same display file.

Note: File level CA and CF keys are extended to the record level. This must be considered when assigning key numbers. For example, if CA02 is specified at file level and CF02 is specified at record level, CF02 is an error.

If you specify a key in the range 1 through 9, you must supply the leading zero in the keyword (for example, CF03).

Option indicators are valid for this keyword.

Function keys valid for command function keys at processing time

As a general rule, the last output operation determines which function keys are valid. The following list shows exceptions to this rule:

When an operation sends no data to the display, the validity of the various function keys is not changed. Such operations include:
- An output operation to a subfile record
- An update to a subfile record
- An output operation to a subfile control record that only clears, deletes, or initializes a subfile without displaying the subfile or the subfile control record
An output operation that displays an error message by selecting ERRMSG or ERRMSGID can also select a CA or CF key to be valid while the error message is displayed.
If SFLDROP is specified for a subfile, the validity of the CA or the CF key specified for the SFLDROP keyword is determined by the last output operation. However, as long as the subfile is displayed, the CA or CF key, when valid, acts only as a Drop key.
If SFLFOLD is specified for a subfile, the validity of the CA or the CF key specified for the SFLFOLD keyword is determined by the last output operation. However, as long as the subfile is displayed, the CA or CF key, when valid, acts only as a Fold key.
If two subfiles using SFLDROP or SFLFOLD are displayed at one time, the same function key should be specified on both the SFLDROP and SFLFOLD keywords. If they are different, only the key specified for the most recently displayed subfile is in effect. Pressing the function key affects the subfile containing the cursor. If the cursor is not positioned in a subfile, the function key affects the upper subfile.
If two subfiles using SFLENTER are displayed at the same time, the only CA or CF key in effect as an Enter key is the CA or CF key specified for the SFLENTER keyword on the most recently displayed subfile. The cursor position at the time the Enter key is pressed determines which subfile is affected.

Note: The ROLLUP and ROLLDOWN keywords function like CF keys.

Example

The following example shows how to specify the CFnn keyword.

|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
00010A                                      CF01(91 'End of Program')
00020A                                      CF02(92)
00030A                                      CF03
     A