ABAP_to_the_Future

6
The Enhancement Framework and New BAdIs
Another example could involve an inte rface from SAP to a monster-making
machine, of which there are 10 possible varieties. Some of them have mandatory
data fields, varying depending on the company that made the machine. These
mandatory fields would be the same in any country where you were using that
variety of machine. However, some (but not all) countries have laws governing
what mandatory information must appear on the external machine’s display;
those laws were created before any machine was even invented, and they are naturally
different between countries.
You can handle this by creating one BA dI implementation for each variety of
machine to validate that each machine-sp ecific mandatory field is filled. Then,
create BAdI implementations for each country that has special laws to validate the
relevant fields as well. When you call the BAdI, any machine-specific checks and
any country-specific checks are performed; if either se t of checks fails, then an
error is raised. There may be no country- specific checks or no machine-specific
checks, and you may need to introduce a new country-specific check if a new law
is created. None of this matters to the calling program: It only needs to handle
any error messages sent to it.
6.6 Summary
This chapter gave you a cr ash course on user exits, focusing on the two most
recent types: BAdIs and the enhancemen t framework. You should now have a
good idea of how (and why!) to use these in your own code.
In the last code sample (Listing 6.4), you will notice comments such as “Do some
error handling.” This was left deliberately vague, because it leads in to the next
chapter, which is all about error handling.
Recommended Reading
왘 How To Define a New BAdI Within the Enhancement Framework:
http://scn.sap.com/people/thomas.weiss/blog/2006/04/03/how-to-define-a-newbadi-within-the-enhancement-framework--part-3-of-the-series
(Thomas Weiss)
왘 Back to the Future: http://scn.sap.com/community/abap/blog/2012/08/31/
back-to-the-future--part-06 (Paul Hardy)
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