Multi Level Tree ALV with CL_GUI_ALV_TREE

DATA : lr_cust TYPE REF TO cl_gui_custom_container,
lr_tree TYPE REF TO cl_gui_alv_tree,
lt_scarr TYPE TABLE OF scarr,
ls_scarr TYPE scarr,
lt_spfli TYPE TABLE OF spfli,
gt_spfli TYPE TABLE OF spfli,
ls_spfli TYPE spfli,
ls_header TYPE treev_hhdr,
lv_node_key1 TYPE lvc_nkey,
lv_node_key2 TYPE lvc_nkey,
lv_node_key3 TYPE lvc_nkey,
lv_node_text TYPE lvc_value.

START-OF-SELECTION.
CALL SCREEN 0001.
*&———————————————————————*
*& Module STATUS_0001 OUTPUT
*&———————————————————————*

MODULE status_0001 OUTPUT.
SET PF-STATUS ‘STATUS’.
*  SET TITLEBAR ‘xxx’.
ENDMODULE.                 ” STATUS_0001  OUTPUT
*&———————————————————————*
*&      Module  GET_DATA  OUTPUT
*&———————————————————————*
MODULE get_data OUTPUT.
IF lt_scarr IS INITIAL.
SELECT * FROM scarr INTO TABLE lt_scarr.
IF lt_scarr IS NOT INITIAL.
SELECT * FROM spfli INTO TABLE lt_spfli FOR ALL ENTRIES IN lt_scarr

  WHERE carrid = lt_scarr–carrid.
ENDIF.
ENDIF.
ENDMODULE.                 ” GET_DATA  OUTPUT
*&———————————————————————*
*&      Module  BUILD_TREE  OUTPUT
*&———————————————————————*
MODULE build_tree OUTPUT.
IF lr_cust IS NOT BOUND.
CREATE OBJECT lr_cust
EXPORTING
container_name              = ‘ALV_TREE’
repid                       = sy–repid
dynnr                       = sy–dynnr
EXCEPTIONS
cntl_error                  = 1
cntl_system_error           = 2
create_error                = 3
lifetime_error              = 4
lifetime_dynpro_dynpro_link = 5
OTHERS                      = 6.

ENDIF.
IF lr_tree IS NOT BOUND.
CREATE OBJECT lr_tree
EXPORTING
parent                      = lr_cust
node_selection_mode         = cl_gui_column_tree=>node_sel_mode_single
item_selection              = ‘X’    ” Can Individual Items be Selected?
no_toolbar                  = ‘ ‘    ” NO_TOOLBAR
no_html_header              = ‘X’    ” NO_HTML_HEADER
EXCEPTIONS
cntl_error                  = 1
cntl_system_error           = 2
create_error                = 3
lifetime_error              = 4
illegal_node_selection_mode = 5
failed                      = 6
illegal_column_name         = 7
OTHERS                      = 8.

ENDIF.
* Prepairing Header
ls_header–heading = ‘FLight Information’.
ls_header–tooltip = ‘Flight Data’.
ls_header–width = 40.
ls_header–width_pix = ‘ ‘.

CALL METHOD lr_tree->set_table_for_first_display
EXPORTING
i_structure_name    = ‘SPFLI’
is_hierarchy_header = ls_header
CHANGING
it_outtab           = gt_spfli. ” table must be initial

* Prepairing Root node
lv_node_text = ‘Flight Code’.
CALL METHOD lr_tree->add_node
EXPORTING
i_relat_node_key     = ‘ ‘
i_relationship       = cl_gui_column_tree=>relat_last_child
i_node_text          = lv_node_text
IMPORTING
e_new_node_key       = lv_node_key1  ” get the root node key
EXCEPTIONS
relat_node_not_found = 1
node_not_found       = 2
OTHERS               = 3.

* Create Hierarchy ( nodes )
LOOP AT lt_scarr INTO ls_scarr.

lv_node_text = ls_scarr–carrid.
CALL METHOD lr_tree->add_node
EXPORTING
i_relat_node_key     = lv_node_key1  ” pass the root node key
i_relationship       = cl_gui_column_tree=>relat_last_child    ” How to Insert Node
i_node_text          = lv_node_text   ” Hierarchy Node Text
IMPORTING
e_new_node_key       = lv_node_key2   ” Key of New Node Key
EXCEPTIONS
relat_node_not_found = 1
node_not_found       = 2
OTHERS               = 3.

LOOP AT lt_spfli INTO ls_spfli WHERE carrid = ls_scarr–carrid.

CALL METHOD lr_tree->add_node
EXPORTING
i_relat_node_key     = lv_node_key2
i_relationship       = cl_gui_column_tree=>relat_last_child
is_outtab_line       = ls_spfli
*         is_node_layout       =     ” Node Layout
*         it_item_layout       =     ” Item Layout
*         i_node_text          =     ” Hierarchy Node Text
IMPORTING
e_new_node_key       = lv_node_key3    ” Key of New Node Key
EXCEPTIONS
relat_node_not_found = 1
node_not_found       = 2
OTHERS               = 3.

ENDLOOP.

ENDLOOP.

* Must Call this method to display nodes on the container
CALL METHOD lr_tree->frontend_update.
ENDMODULE.                 ” BUILD_TREE  OUTPUT
*&———————————————————————*
*&      Module  USER_COMMAND_0001  INPUT
*&———————————————————————*
MODULE user_command_0001 INPUT.
CASE sy–ucomm.
WHEN ‘BACK’ OR ‘EXIT’ OR ‘CANCEL’.
LEAVE TO SCREEN 0.
ENDCASE.
ENDMODULE.                 ” USER_COMMAND_0001  INPUT