ABAP_to_the_Future

12
Web Dynpro ABAP and Floorplan Manager
changed will be unaware of what you have changed and thus not dependent on it
in any way (and so they cannot break).
The end result of all this is that in Listing 12.1 you saw that the view was getting
the data by calling a method of its controller—so you need to go to the COMPO-
NENTCONTROLLER node and create such a method, with the exact same parameters
as the corresponding method in ZCL_MONSTER_MODEL. Then add the coding as
shown. The view only knows about the controller and no other layers.
In Listing 12.2, you see the listing of that method in the controller, which is not
very exciting; all it does is make the same request of a method in the model with
the exact same name and signature.
METHOD retrieve_headers_by_attribute .
wd_this->mo_monster_model->retrieve_headers_by_attribute(
EXPORTING
it_selections = it_selections
IMPORTING
et_monster_headers = et_monster_headers ).
ENDMETHOD.
Listing 12.2 Controller Method to Retrieve Monster Header Data
This leads to the stage in which the user can enter a monster name such as Fred
and get an ALV grid of monster header records. Now, you need to allow the user
to drill down into a single monster record.
Navigating to the Single Record View
Earlier, when you created a button to show the selected monster, you also created
a corresponding action. A method is automatically generated for you to handle
that action, so go to the V_HEADER_GRID view and fill in the code for the ONACTION-
SHOW_MONSTER method. The code for this is shown in Listing 12.3.
METHOD onactionshow_monster .
* Find the node where the monster header table lives
DATA lo_node_monster_header_table TYPE REF TO if_wd_context_node.
lo_node_monster_header_table = wd_context->get_child_node(
name = wd_this->wdctx_monster_header_table ).
* Get all the selected elements (lines).In fact there is only one
* but as in some applications the user can select more than one
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