ABAP_to_the_Future

8
Business Object Processing Framework (BOPF)
Click the Next button, and you’re now ready to define the top-level (header)
node.
What is a GUID?
At this stage, you may be asking yourself what in the world a constants interface
is. This interface is needed when you start making assorted customizing settings,
because there will be quite a few 32-character hexadecimal GUIDs (see box ahead
for more info) generated for accessing various parts of your monster object. This
is very common in modern SAP frameworks. To hide these GUIDs from programmer
eyes, the system will generate constants with English names that you can use
instead. These constants will live inside an ABAP interface—in this example, ZIF_
MONSTER_C. Thereafter, your custom programs can refer to ZIF_MONSTER_C=>MON-
STER as opposed to A00765432100EF00.
GUID stands for “Globally Unique Identifier,” and there is a very good (and very funny)
explanation of GUIDs to be found on the web at http://betterexplained.com/articles/thequick-guide-to-guids.
This is a universal idea, but the application within SAP is that instead of having an identification
number (or name) for an object such as a customer or ABAP artifact, you have a
really long hexadecimal string. This string is then used as the primary key in a database table.
The benefit is that it really is a unique number, and database access using such a number
is really fast. The downside is that such numbers are not understandable by humans,
and you need a mechanism to present such keys to human beings via some sort of alias
(i.e., FRED BLOGGS instead of 30dd879c-ee2f-11db-8314-0800200c9a66).
It’s worth noting that virtually all new SA P technology uses GUIDs (e.g., BRFplus, as
well as the BOPF framework presented in this chapter).
8.1.2 Creating a Header Node
The next screen that appears is shown in Figure 8.3. This is where you define the
so-called root node, like the top level of an XML tree or an IDoc; again, this terminology
is increasingly common in SAP. You will see the same term used later
on in the book when talking about shared memory. In this case, you can think of
this as the header, like table VBAK. (Later on, you’ll understand the connection to
the item table, but for now just concentrate on the header table.)
You will see you have a field for Root Node Name, which is filled by default with
ROOT. You have to change this to a different name; in this example, enter “MON-
STER_HEADER”.
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