Doubt with generation of code WD ABAP Using Wizard

Question

Dear Experts.
I am reading documentation, Wikis, etc for WD ABAP.
Web Dynpro for ABAP: Tutorials for Beginners [original link is broken]
However my doubt is in this moment when I am generating the code using the Wizard. For example:
In this moment I am creating an application of example using:
Using Select-Options in Web Dynpro for ABAP.
However I want know how is generated this code:
METHOD WDDOINIT .
  DATA: LT_RANGE_TABLE TYPE REF TO DATA,
        RT_RANGE_TABLE TYPE REF TO DATA,
        READ_ONLY TYPE ABAP_BOOL,
        TYPENAME TYPE STRING.
  DATA: LR_COMPONENTCONTROLLER TYPE REF TO IG_COMPONENTCONTROLLER,
        L_REF_CMP_USAGE TYPE REF TO IF_WD_COMPONENT_USAGE.
* create the used component
  L_REF_CMP_USAGE = WD_THIS->WD_CPUSE_SELECT_OPTIONS( ).
  IF L_REF_CMP_USAGE->HAS_ACTIVE_COMPONENT( ) IS INITIAL.
    L_REF_CMP_USAGE->CREATE_COMPONENT( ).
  ENDIF.
  WD_THIS->M_WD_SELECT_OPTIONS = WD_THIS->WD_CPIFC_SELECT_OPTIONS( ).
* init the select screen
  WD_THIS->M_HANDLER = WD_THIS->M_WD_SELECT_OPTIONS->INIT_SELECTION_SCREEN( ).
  WD_THIS->M_HANDLER->SET_GLOBAL_OPTIONS(
                              I_DISPLAY_BTN_CANCEL  = ABAP_FALSE
                              I_DISPLAY_BTN_CHECK   = ABAP_FALSE
                              I_DISPLAY_BTN_RESET   = ABAP_FALSE
                              I_DISPLAY_BTN_EXECUTE = ABAP_FALSE ).
* create a range table that consists of this new data element
  LT_RANGE_TABLE = WD_THIS->M_HANDLER->CREATE_RANGE_TABLE( I_TYPENAME = 'S_CARR_ID' ).
* add a new field to the selection
  WD_THIS->M_HANDLER->ADD_SELECTION_FIELD( I_ID = 'S_CARR_ID'
  IT_RESULT = LT_RANGE_TABLE I_READ_ONLY = READ_ONLY ).
ENDMETHOD.
The page of example is:
Moderator Message: Illegal external link removed.
Remove the * in the page of above
Anyone can help me with suggestions.
I want learn WD ABAP.
Regards
Carmen G
Edited by: Thomas Jung on Jan 5, 2011 1:02 PM

Answer 1

>This code is generate with Wizard?
Probably not, but what difference does it make either way.
>How I know the that do this methods?
What?  I have no idea what you are asking.
If you just want to know what these lines of code are doing, here is an explanation.
WD_THIS->M_WD_SELECT_OPTIONS = WD_THIS->WD_CPIFC_SELECT_OPTIONS( ).
This line of code is storing an object reference to the Selection Options Component Interface (necessary for accesing interface methods of the reuable select-options component).
  WD_THIS->M_HANDLER = WD_THIS->M_WD_SELECT_OPTIONS->INIT_SELECTION_SCREEN( ).
Using the reference to the component interface from the first line of code, this line now calls a method of the selection option component that initializes the selection screen.  It returns an object reference to the select option handler.  This handler object can be used to set options of the selection screen.
  WD_THIS->M_HANDLER->SET_GLOBAL_OPTIONS(
                              I_DISPLAY_BTN_CANCEL  = ABAP_FALSE
                              I_DISPLAY_BTN_CHECK   = ABAP_FALSE
                              I_DISPLAY_BTN_RESET   = ABAP_FALSE
                              I_DISPLAY_BTN_EXECUTE = ABAP_FALSE ).
Using the handler object from the previous line of code, this line now sets the global configuration objects of the selection screen.  For instance it makes all the default buttons (cancel, check, reset and excuate) hidden.