× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



This seemed simple enough on the face of it, and then of course it slipped away.

A case has been made for dividing the pieces of an application into, as I understand it, at least three layers.

The first layer is the data and it's constraints and security.
The second is the layer for business rules.
The third is the top layer, for the user interface, allowing several different UI solutions to co-exist at the same time.

That all makes sense to me.

Two problems are confusing me. The second one is: what mechanism does one use to arrange the data for the mating of the UI layer to the business rules layer? The business rules program, as I understand the design, has to not know or care whether the user interface is RPG, Java, or whatever. What, specifically, does the business rules program expect to get & send from & to the UI?

Here's a simple example: A data file with 2 key fields and a 480-char data field. The UI needs to display the key fields and also a single record. Add/update/delete are possible when the single record is displayed.

(Maybe this is all too simple for layering, but I sooner expect that I don't really understand the process itself.)

As an Amazon Associate we earn from qualifying purchases.

This thread ...

Follow-Ups:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.