Re: Separate buisness and display logic question

Comments in-line.

Jon Paris

www.Partner400.com
www.SystemiDeveloper.com


On Feb 3, 2011, at 12:57 PM, rpg400-l-request@xxxxxxxxxxxx wrote:

If you have a situation where you cannot change the parms (perhaps
because the program is called in multiple places) but you need
additional data the LDA is a good tool to use.

Well for one I see no reason what an additional optional parm could not be added. But even without that - No it isn't. Using the LDA is the equivalent of driving the wrong way on the interstate - it is not a question of _if_ you will crash but _when_. If you can't add an extra parm then at least use customer data area designed for the purpose.

Another example is
setting up the environment so all of the programs in a job have access
to necessary data without the need to pass it around. Using the LDA
also has less of a performance hit than other solutions.

Again what's wrong with a data area designed for the purpose.

If you are concerend about standardization then you can create an LDA
standard for your shop, just like you do with other everything else.

No you can't. Not in practice because a) You might run an old package that thinks it owns the LDA or b) Buy another company whose software also has a "standard" for the LDA or ...

Just because something is old doesn't mean it isn't useful. What are
your objections to using the LDA?

True - I'm pretty old and hopefully still useful. I've stated a few objections above. If you were talking about existing software (maybe with an S/36 legacy) then I would not insist that it be changed for the sake of it. But we're talking about new software here and it seems very foolish to me to build anything new using a technique that has been obsolete for years. There were good reasons why data areas, user spaces (my preference), exported data items, parameters, etc. were added to capabilities such as the LDA.