Hi,
From the path it's the below code. lo_action contains the instance of cl_wd_action and in that am accessing parameters which is public attribute.
DATA lo_api_controller TYPE REF TO if_wd_view_controller.
DATA lo_action TYPE REF TO if_wd_action.
DATA ls_action TYPE wdr_name_value.
lo_api_controller = wd_this->wd_get_api( ).
lo_action = lo_api_controller->get_current_action( ).
READ TABLE lo_action->parameters INTO ls_action WITH KEY name = 'ID'.
ls_action-value will contain the button ID (WD_OK or other).
hope this helps,
Regards,
Kiran