*&---------------------------------------------------------------------*
*& Report  ZTREELOCAL
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*
REPORT ztreelocal.

SELECTION-SCREEN BEGIN OF BLOCK blc1.
PARAMETERS p_tplnr TYPE tplnr DEFAULT 'PS110-000777'.
SELECTION-SCREEN END OF BLOCK blc1.

*--------------------------------------------------------------------*]
CLASS lcl_tree_node DEFINITION DEFERRED.
*--------------------------------------------------------------------*
INTERFACE lif_tree_node.

  METHODS
          : haschild
              RETURNING VALUE(r_bool) TYPE abap_bool
          , addchild
              IMPORTING i_name   TYPE string
                        i_parent TYPE REF TO lcl_tree_node
          , output
          .

ENDINTERFACE.
*--------------------------------------------------------------------*
CLASS lcl_tree_node DEFINITION.
  PUBLIC SECTION.

    INTERFACES lif_tree_node.
    ALIASES
            : haschild FOR lif_tree_node~haschild
            , addchild FOR lif_tree_node~addchild
            , output   FOR lif_tree_node~output
            .
    METHODS
      : constructor IMPORTING i_name   TYPE string
                              i_parent TYPE REF TO lcl_tree_node OPTIONAL
                  .
  PRIVATE SECTION.
    DATA
          : name   TYPE                 string
          , parent TYPE REF TO          lcl_tree_node
          , childs TYPE TABLE OF REF TO lcl_tree_node
          .
ENDCLASS.

CLASS lcl_tree_node IMPLEMENTATION.
*--------------------------------------------------------------------*
  METHOD constructor.
    me->name   = i_name.
    me->parent = i_parent.
  ENDMETHOD.
*--------------------------------------------------------------------*
  METHOD haschild.
  ENDMETHOD.
*--------------------------------------------------------------------*
  METHOD addchild.
    DATA(lo_child) = NEW lcl_tree_node( i_name = i_name
                                        i_parent = i_parent ).
    APPEND lo_child TO childs.
  ENDMETHOD.
*--------------------------------------------------------------------*
  METHOD output.
    WRITE / me->name.

    LOOP AT childs ASSIGNING FIELD-SYMBOL(<lo_child>).

      <lo_child>->output( ).

    ENDLOOP.

  ENDMETHOD.
*--------------------------------------------------------------------*
ENDCLASS.

START-OF-SELECTION.
  BREAK-POINT.

  DATA(lo_root) = NEW lcl_tree_node( conv string( p_tplnr ) ).


  lo_root->addchild( i_name   = CONV string( |{ p_tplnr }-001 | )
                     i_parent = lo_root ).

  lo_root->output( ).