ABAP_to_the_Future

Using BOPF to Write a DYNPRO-Style Program 8.2
event, you could run the validation on every roundtrip if you wanted, or only
when the user presses some sort of Check button, just like when you’re entering
a supplier invoice in Transaction MIRO.
What actually defines a consistent object is naturally very application-specific; for
example, a sales order with no items or no customer is not much good. In this example,
say that if you enter a hat size for the monster, then the monster has to have a
head. It’s always the job of the model to know what data is consistent and what is
not. Using this example, you’ll learn how to create and then code a validation.
Creating the Validation
To create the validation, open Transaction BOB, and select the MONSTER_HEADER
node. Right-click on it, and choose the context menu option Create Consistency
Validation. By this point, it will probably not come as much of a shock to you
that a wizard appears to guide you thro ugh the creation process. The first two
screens are nothing special: just choose a name (which will be used to generate
the implementing class) and a text descri ption, and then the name of the implementing
class is proposed.
This time, you can choose when the vali dation will be run by selecting checkboxes
(Figure 8.15). Note that you can, for example, tell the system to run a validation
on the header data when item data is changed or vice versa.
Figure 8.15 Choosing when a Validation Runs
Note that the checkboxes in Figure 8.16 control the automatic running of the validation
by the framework at update time. Because the validation is implemented
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