User Access Utilities › Menus › Menu Manipulation Commands › Messages and the Menu Program

Messages and the Menu Program

i OS has sophisticated message handling facilities that enable you both to provide a continuous dialogue between user and machine, and to obtain an audit log. The Toolkit display menu program helps you to make full use of i OS messages, and includes the following features:

• The menu program has a program message queue subfile: all messages appear on line 24 as a subfile. You can examine the messages by moving the cursor to line 24 of the menu display, and scrolling up or down and/or pressing Help.
• If your programs crash, the escape messages will automatically be trapped and displayed on the message line.
• Completion messages and diagnostic messages will automatically be displayed on the message line, where they can be scrolled.
• Your own messages can be made to appear on the message line of the menu display, complete with second level Help text and substitution variables. To make a message appear on the display you may ei Simply send the message to the previous program message queue in the invocation stack.

For example, the following impromptu message will cause HELLO SAILOR to appear on line 24 of the menu display:

SNDPGMMSG MSG(‘HELLO SAILOR’)

While this predefined message:

ADDMSGD MSGID(USR0001) MSGF(QUSRMSG) MSG(‘&1 Pints today
&2’) SECLVL(‘Must be gold top.’) FMT((*DEC 3) (*CHAR 10) )

will cause the message "002 Pints today please" to appear on line 24 if it is sent to the menu program by your own CL program:

SNDPGMMSG MSGID(USR0001) MSGF(QUSRMSG) MSGSend the message directly to a named program message queue. If you have nested invocations of application programs - program A calling program B calling program C - you may wish to send messages directly to the Toolkit menu program by name. Such messages should be sent to the Toolkit menu message handling program YDMNGOC. For example:

SNDPGMMSG MSGID(USR0001) MSGF(QUSRMSG) MSGDTA(‘002please’) TOPGMQ(*SAME YDMNGOC)

The menu program provides a completion message for each option executed. The message (YMN0027 in the Toolkit message file, YYYYMSG) has the form:

Last option was "N." "option text"

Use of this feature can reduce the amount of CL programming that you have to do.

• The execution messages of programs called by menu options will be logged according to the job’s logging level: refer to chapter 13 in the i OS Programmers Handbook for details on message logging levels.
• Request messages are also logged: it is possible to use the display low level messages facility (F10) of the command entry display to examine request messages that were initially sent as the result of taking menu options on a Toolkit menu.

  The message logging level of your jobs, which can be changed by, for instance, the i OS command Change Job (CHGJOB) - affects which messages are displayed in your log.