4.18.1 Function Control Table and Menu Selection Style: FUNCTION
4.4 Create a New Process Definition describes the menu selection style options available in LANSA. This allows the style of menu selection used for the process's main menu to be specified as one of the following (ignoring ACT/BAR which causes the process to act as an action bar):
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SAA/CUA |
Design menu according to IBM's SAA/CUA guidelines. This is the recommended style for LANSA. As such, much of this section of the manual is now redundant, and is retained purely for the continuance of older style systems. |
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CURSOR |
Select entries using the screen cursor. |
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NUMBER |
Select entries by entering the associated number. |
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FUNCTION |
Select entries by entering the "next function" name. |
While the function control table can be used effectively with all 3 menu selection styles it is more "visible" and more flexible when using the FUNCTION selection style and is thus easiest to explain.
FUNCTION style selection basically means that you indicate what you wish to do next by entering the name of the function into a field at the bottom of the current screen.
If you are using FUNCTION style selection then at the bottom of the process's main menu and every screen used by the functions associated with the process a field called "the next function field" will appear like this:
Next function : FUNC2
F1=Help F3=Exit F12=Cancel F14= Messages
What this field is asking is "When you have finished here what do you want to do next?"
The "next function field" will always be pre-filled with the default next function from the function control table. The value is "suggesting" what you would normally do next (and it may be the only thing that can be done next) but it can be changed if desired.
This is what makes FUNCTION style selection more flexible than the other selection styles. It effectively allows a choice about what selection can next to be made from within a function as well as from the process's main menu.
This means that it is possible to go from FUNC1 to FUNC2 then to FUNC3 without once displaying the process's main menu.
Of course the process control table can be used in exactly the same way when using selection styles CURSOR or NUMBER. The user can go directly from FUNC1 to FUNC2 and then to FUNC3 without displaying the process's main menu. The difference is that because the "next function" field is not displayed when using these menu selection style he/she is forced to follow the path and cannot change it.
When using FUNCTION style selection in FUNC1 the "next function field" might be "suggesting" next function FUNC2. But, because it is displayed, it can be changed to something else (FUNC17 for example) thus altering the path that is being followed. Whether or not FUNC17 is actually a valid choice depends upon the allowable next functions list in the associated function control table entry.