ABAP_to_the_Future

8
Business Object Processing Framework (BOPF)
There are lots of choices here, including the following:
왘 Derive dependent data immediately after modification
This is analogous to the equivalent PAI (processing after input) concept you’re
used to. By selecting this, you’re telling the program that after the user changes
data you want to update other fields based upon what has been changed.
왘 Derive dependent data before saving
This option refers to a case when you change fields the user doesn’t even know
about (they’re not on the UI, for exam ple) based upon the entered data. By
selecting this, you tell the program to ch ange the value of certain fields based
on others after the user has chosen the Save option, and to do so without
informing the user that such fields ha ve changed. For example, the technical
monster type is not something the user would understand (it only makes sense
to a mad scientist), but it’s derived from the requirements the user enters.
왘 Fill transient attributes of persistent nodes
This is analogous to the PBO (processing before output) concept you know and
love. Before showing the user a UI screen, you need to fill in the text fields and
calculated fields. If you choose this, you’re telling the program that you want to
fill out certain derived fields based on other fields such that all the derived
fields are full when we show them to the user.
왘 CREATE PROPERTIES
This option is for when you want to make fields read only or mandatory, based
on other data. You often see this in standard SAP; for example, once a delivery
has been goods issued a lot of the fields go gray so you can no longer change
them. This example does not create such a determination, but you could imagine
a scenario where, if the user fill s a checkbox saying the monster must eat
mountains every day, then the field How Many Mountains becomes mandatory.
The Derive Instance of Transient Nodes option is grayed out, so you cannot
choose that.
Once you’ve created your determination, you can see in a nice graphical manner
what determinations get run for what nodes (Figure 8.14), and you can even control
what order they get run in. You mi ght want to count the number of items
first, for example, and then store that number in a transient attribute in the
header row.
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