Re: PRTF Overflow


Hello Peter,

How far do you go?  Well, it depends on what you're after.  My view is that 
in-house code can 
get away with assuming things about the environment but software-house code 
can't.  (I just 
wish more software houses thought that way!!!!)

I think it reasonable that the program at least check to ensure that the data 
it is about to 
print can actually be printed successfully given the current spooled file 
attributes.  For 
example, if the report is designed for 132 column width but is actually printed 
on 80 column 
width, the program can take one of three options.

        1/ Print anyway and blame the environment for the problem
        2/ Check the printer file width and complain if below the expected width
        3/ Open multiple printer files and print as much as will fit in the 
width and then 
print the rest in additional spooled files (much like Query Management does).

I think option 1 is a cop-out, the haven of lazy programming.  Option 3 
involves quite a bit of 
work and is not so easy to do from RPG (other languages have better support for 
dynamic files).  
Option 2 seems a good compromise and doesn't take much effort to implement.

Similar choices are available for page length.  Here though the complaint would 
occur only when 
the page size was reduced to below that required for the headings and one group 
of detail 
records.

As I explain to my students when they ask similar questions, this stuff is only 
difficult the 
first time you have to think about it.  After that, it becomes second nature 
and the same basic 
approach can be implemented by cloning.  I think coping with this sort of stuff 
(along with 
exception handling, encapsulation, variable scoping, complex data structures, 
and other things) 
is the difference between being an average programmer and being a good 
programmer.

Regards,
Simon Coulter.

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//--- forwarded letter -------------------------------------------------------
> X-Mailer: Microsoft Outlook Express 5.00.2314.1300
> Date: Sat, 11 Dec 1999 13:41:20 -0800
> From: "Peter Dow" <pcdow@yahoo.com>
> To: RPG400-L@midrange.com
> Reply-To: RPG400-L@midrange.com
> Subject: PRTF Overflow

> 
> Just after I sent that it occurred to me that if you're worried about
> someone changing the printer file used by your programs, do you also handle
> changed page widths, font sizes, etc.? How far do you go?
> 
> ----- Original Message -----
> From: Simon Coulter <shc@flybynight.com.au>
> To: <RPG400-L@midrange.com>
> Sent: Saturday, December 11, 1999 3:25 AM
> Subject: Re: PRTF Overflow
> 
> 
> >
> > Hello Peter,
> >
> > It doesn't matter if the groups are fixed sizes or not.  The real problem
> is that the program
> > cannot assume the page length.  If I follow your example and someone
> alters the page size of
> > the printer file used by my program I will have groups of records spanning
> pages because the
> > rules changed.  Anytime you are printing blocks of records you should use
> the feedback area
> > because things can change outside your program -- and your program should
> still cope -- belts
> > and braces -- bug-free and all that!
> >
> > Regards,
> > Simon Coulter.

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