Re: Can a Command Validity Check program be an RPG ILE program

On Thu, Feb 9, 2012 at 12:04 PM, John Allen <jallen@xxxxxxxxxxx> wrote:

... I wanted a way to reverse image the field where the error was found
and keep
the command up on the screen.
Sort of like when Restricted values are defined in the Command and they
enter an invalid value.

Was I expecting too much?
The way it works now, I am just moving my validity checking from the
Command
Processing program to a Validity checking program.
What do I gain by using the validity checking program??

There is no provision for the VCP to indicate which parameter is in error.

IMHO a VCP is best used for syntax and values validation that cannot be
expressed with PARM and DEP commands in the command definition. Run-time
validation (e.g., object existence or other external resource access) is
best left in the CPP to avoid signaling errors at inappopriate times, as
in SEU or CL compile when the compile unit includes your command (and VCP
invocation).

If you can code express your syntax rules with DEP commands, that is the
way to go. Command processing will be able to identify the parameter in
error and display the message you specify at the appropriate time,
including during prompting.