How to get the selected entry from a Dropdown (using IF_WD_SELECT_OPTIONS)

Question

Hello,
I created a Selection screen by adding attribute M_HANDLER of type IF_WD_SELECT_OPTIONS.
This way I can create a selection screen with normal select-options.
Now I added a parameter for a dropdown list. The Value set is passed correctly. No problem there. The values are filled and diplayed correctly.
* add the SHIP-TO field to the selection
  DATA: ltp_text  TYPE string.
  DATA: lta_ship_to_table type WDY_KEY_VALUE_table,
        lwa_ship_to       like LINE OF lta_ship_to_table.
  DATA: context_node_ship_to_table TYPE REF TO if_wd_context_node.
* get all declared attributes
  context_node_ship_to_table = wd_context->get_child_node( 'SHIP_TO_TABLE' ).
  context_node_ship_to_table->get_static_attributes_table(
    IMPORTING
      table  = lta_ship_to_table ).
  ltp_text = wd_assist->if_wd_component_assistance~get_text( 'L01' ).
  wd_this->m_handler_dlv->add_parameter_field(
                         i_id           = 'KUNWE'
                         i_description  = ltp_text
                         i_as_dropdown  = 'X'
                         it_value_set   = lta_ship_to_table
                         i_within_block = 'BLK1' ).
The problem is to GET the selected value in the method that is called after clicking on the Search button.
I tried using several methods, for example GET_PARAMETER_FIELD and GET_SELECTION_SCREEN_ITEMS.
* Get the Ship-to
  DATA: ltp_kunwe       TYPE REF TO data.
  ltp_kunwe = wd_this->m_handler_dlv->get_value_of_parameter_field(
                                        i_id = 'KUNWE' ).
* Assign it to a field symbol
  ASSIGN ltp_kunwe->* TO <fs_kunwe>.
Result was INITIAL.
DATA: lrf_get_selection_screen_items TYPE if_wd_select_options=>tt_selection_screen_item.
  wd_this->m_handler_dlv->get_selection_screen_items(
              IMPORTING
                 et_selection_screen_items = lrf_get_selection_screen_items ).
Result was INITIAL, although the table was retrieved with all values.
wd_this->m_handler_dlv->get_parameter_field(
                                      EXPORTING
                                        i_id = 'KUNWE'
                                      IMPORTING
                                        e_value = ltp_kunwe ).
Also INITIAL.
It looks like I am missing a step (maybe to set lead selection for this field). What did I miss?
How can I get to the value?

Answer 1

Thanks!
Problem solved:
DATA: lr_value             TYPE REF TO data.
CREATE DATA lr_value TYPE string.                     "<----  I was missing this code
  LOOP AT lta_ship_to_table INTO lwa_ship_to.
    value_set-key   = lwa_ship_to-key.
    value_set-value = lwa_ship_to-value.
*    INSERT value_set INTO TABLE lt_value_set.
    append value_set TO lt_value_set.
  ENDLOOP.
  ltp_text = wd_assist->if_wd_component_assistance~get_text( 'L01' ).
  wd_this->m_handler_dlv->add_parameter_field(
                          i_description  = ltp_text
                          i_id           = 'KUNWE'
                          i_value        = lr_value   "<----  I was missing this code
                          i_as_dropdown  = abap_true
                          it_value_set   = lt_value_set
                          i_within_block = 'BLK1' ).
I looked at that parameter, but thought is was only used to SET the value, not required to get it back as well. Because it IS an import parameter...