ABAP_to_the_Future

12
Web Dynpro ABAP and Floorplan Manager
When you create a module pool transaction, you specify which screen you are
going to be starting on; the same idea ap plies here. As noted earlier, when the
WDA application is called, you’re going to start on the V_HEADER_GRID view inside
the W_MONSTER_MONITOR window. As soon as you’re done specifying this and click
the good old green checkmark, a whole bunch of objects are generated for you, as
can be seen in Figure 12.5.
Figure 12.5 Empty WDA Component
You have your proper controller, another controller called the interface controller
(which we are going to use in order to reuse the standard ALV functionality available
in WDA), and your window and vi ew (which are both views in the MVC
sense). If you went into the root node and specified an assistance class, then that
would be in the tree structure as well, and it would look like you had child nodes
for a model, controller, and views. Howe ver, even if that looks nice, remember
that an assistance class is not really th e model but a sinister impostor that rises
above its text-handling station to try an d subjugate the entire universe and torture
us all to death slowly in its salt mines—so don’t do that.
12.2.2 Declaring Data Structures for the Controller
If you were writing a DYNPRO program, then right about now you’d be declaring
TABLE statements in your TOP INCLUDE for DDIC structures and maybe some
global variables that you knew you’d be using in your UI screen. In WDA, there
is a clear separation between the data in the view, controller, and model layers,
and you have to explicitly say that yo u want to move data between them. Even
given that life is not so different in the WDA world, at this point you’re still going
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