ABAP_to_the_Future

6
The Enhancement Framework and New BAdIs
GET BADI lo_monster_badi
FILTERS
country = yif_vc_monster_handler=>great_britain
monster_type = ld_monster_type_name.
Listing 6.3 Forcing a Constant to Be Passed in to a BAdI Call
Note
Although limiting the possible input values to a filter to hard-coded constants stops the
calling program from passing in incorrect valu es, this approach is not really that useful
most of the time, because you tend to want the freedom to pass a variable in. In fact,
most of this chapter is about avoiding hard-coding of any sort.
The next option for setting a check on filter values is one that may appeal to you:
defining a check via your own program. Ninety-nine times out of 100, a check on
a data element ought to be good enough, but there are always going to be cases in
which your specific needs aren’t handled by the standard system; in effect, what
you have here is a user exit for the process of defining user exits!
As you can see in Figure 6.17, this pr ocess involves choosing a class name and
some information about the filter value data field.
Figure 6.17 Checking a Filter Value via Your Own Program
If you then double-click on the class name you’ve chosen, you’re taken into SE24
to create the class. The important thing is that the system automatically creates a
class that implements the IF_FILTER_CHECK_AND_F4 interface. Then, you just need
to create an implementation of the four methods in that interface, which are as
follows:
왘 SHOW_F4_ICON
Set the returning parameter SHOW_F4_ICON to be ABAP_TRUE, and then you will
be alerting any programmer who wants to choose a filter value while implementing
a BAdI that an (F4) help is available for choosing the filter value.
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