ABAP_to_the_Future

9
BRFplus
9.6.2 Application Exits
When you define an application in BRFplus, there is an option field called Application
Exit, which really means “user exit.” In this field, you can specify a Z class
that implements a special BRFplus interfac e. Thereafter, at certain points during
BRFplus processing, the methods of this class are called and can change or replace
the standard behavior of the BRFplus framework.
For example, you can totally replace the authorization checks with your own custom
ones. This is no small thing, because you will be opening up BRFplus to let
business experts make some changes, so you had better make everything expert
proof. Another common usage is to add custom formulas (by way of static ABAP
methods) to the standard list of available choices in the Formula expression.
9.6.3 Custom Frontends
Chapter 12 will talk about Web Dynpro. BRFplus runs with a Web Dynpro frontend,
and during construction the inventorof BRFplus thought to himself that the
SAP customers (like you and me) might not be happy with the standard BRFplus
user interface and might want to write their own.
How correct he was! Developers like meare never happy, and I would rather my
business experts be unaware that there is a thing called BRFplus. Instead, I
would give them a screen to change thei r business rules that looks just like the
other custom screens our de velopment department has written for them or, to
be brutally honest, a screen that look s just like their legacy system, which is
what they really want to keep on using. (Once I ported an access database to SAP
and made the screens in SAP look like the old access database—only grayer—
and for once we did not get a peep of complaint from the users about making
the change.)
The good news is that you can write custom frontends for maintaining BRFplus
rules. I’m not going to say it’s easy; you need to know your Web Dynpro, for
starters. For more information, check out the SAP PRESS book BRFplus—Business
Rule Management for ABAP Applications (see the “Recommended Reading”
box at the end of the chapter), which covers the public API of BRFplus classes so
that you can call them from your own custom programs. That book also tells you
how to go about the Web Dynpro aspect of writing your own custom frontends.
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