Re: ILE Conversion

Hi Mark,

On Mon, 3 Jul 2000, Mark Walter wrote:
> 
> Regarding screen handling: The current program maintains 10 screens in one 
> display file. Would it be advantageous to place each display format in it's 
> own display file or to continue to place all of the screens in one display 
> file and just maintain each format in it's own module.

I guess there might be circumstances where you'd want to split the screens
up, but in 95% of the cases, I'd recommend putting all of the screens
together into one module (seperate from your main source).  I'd leave them
all in the same display file.

The idea is, if you wanted to do your screen I/O some other way, such as
have a graphical front-end, or have a program do the typing instead of a
user, you could just bind to a different module, replacing the
display-file I/O with some other method without having to change the 
application logic.

> 
> Regarding externalizing I/O: I would appreciate any input and experiences 
> on this. I'm sort of on the fence about this one. I read the chapter in the 
> Redbook about it and it seems interesting however it also seems like a lot 
> of work to implement.

Depends on the application.  If this is a file that will used the same way
from just about every application, it makes sense to externalize it so you
aren't re-writing the routine for each program.

But if this is a file thats used many different ways to do many different
things, you'd have to make your routines so generic that it would defeat
the purpose.  For example, if you wanted something like "customer_add()"
that would add a record to the customer file, perhaps update a few other
corresponding files, and send E-mail to the account rep letting him know
that his new customer is online, thats great.  It saves having to re-code
all of that in different programs.

However, if you find yourself doing something like "customer_setll(),
customer_reade(), customer_chain(), customer_write()" it seems to defeat
the purpose.  You probably aren't gaining anything by putting this into
a seperate service program, and might as well just use an externally
defined file.

Good luck...



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