HOOK_UNKNOWN_MACRO

This configuration macro allows you to intercept the error handling when a macro was not found. If the hook does not exist then PPWIZARD will simply abort displaying the usual error message.

The hook allow you to either supply a value for the non-existent variable or alter the error message. The hook should not perform any macro substitution.

This variable defines the name of a macro which contains the rexx code to be executed, this code should be "pre-expanded" (not contain any references to macros).

The rexx code gets passed these variables:

• HookDefineName
  This read-only variable contains the name of the missing definition (in original case).

• HookDefineContinue
  This read-write variable initially has a value of "N". On return from the hook a value of "Y" means that you have supplied a replacement value and you wish processing to continue, anything else indicates you still wish to abort processing.

• HookDefineValue
  This read-write variable initially contains the default error message. You can replace this message but I suggest that in general you append to this text (using "'0A'x" for newlines wherever appropriate.

Example

;--- Define hook ------------------------------------------------------------
#DefineRexx 'HOOK_UNKNOWN_MACRO'
    ;--- Handle specifc variables -------------------------------------------
    if  translate(HookDefineName) = 'SOMEMACROWHICHWEWILLCONTINUEON' then
    do
        ;--- We will supply the value for this macro ------------------------
        HookDefineValue    = "{{This macro does not exist}}";
        HookDefineContinue = 'Y'
    end;

    ;--- Finished all known substitutions -----------------------------------
    if  HookDefineContinue = 'N' then    ;;Did we substitute a value?
    do
        ;--- Update the error message we will display -----------------------
        HookDefineValue = HookDefineValue || '0A0A'x || 'Perhaps this is an obsolete WISEINST variable?'
    end;
#DefineRexx

;--- Test Hook --------------------------------------------------------------
C. <$SomeMacroWhichWeWillContinueOn $$UPPER>
D. <$XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX>

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PPWIZARD Manual

Saturday May 28 2022 at 2:55pm