Add/Edit/Delete Tree Nodes using CL_GUI_ALV_TREE

Question

Hi All,
I am looking for an example of program with CL_GUI_ALV_TREE that have a functionality of add a tree node, edit a tree node, and delete a tree node.
I have already looked the BCALV_TREE* demo program but could not able to find a program to add/edit/delete node tree elements.
Any info on this.
Thanks
aRs

Answer 1

Hello aRs
Here is a sample report showing how to delete nodes in an ALV tree. The report was copied from BCALV_TREE_01. Search for added code:
*$ADDED: begin
*$ADDED: end[/code]
When you display the tree expand the first folder completely. When entering 'DELETE' into the command field directly the first flight date node will be deleted.
REPORT ZUS_SDN_BCALV_TREE_01_DELNODE.
based on: REPORT  bcalv_tree_01.
Purpose:
~~~~~~~~
This report shows the essential steps to build up a hierarchy
using an ALV Tree Control (class CL_GUI_ALV_TREE).
Note that it is not possible to build up this hierarchy
using a simple ALV Tree Control (class CL_GUI_ALV_TREE_SIMPLE).
To check program behavior
~~~~~~~~~~~~~~~~~~~~~~~~~
Start this report. The hierarchy tree consists of nodes for each
month on top level (this level can not be build by a simple ALV Tree
because there is no field for months in our output table SFLIGHT.
Thus, you can not define this hierarchy by sorting).
Nor initial calculations neither a special layout has been applied
(the lines on the right do not show anything).
Note also that this example does not build up and change the
fieldcatalog of the output table. For this reason, all fields
of the output table are shown in the columns although the fields
CARRID and FLDATE are already placed in the tree on the left.
(Of course, this is not a good style. See BCALV_TREE_02 on how to
hide columns).
Essential steps (Search for '§')
~~~~~~~~~~~~~~~
1.Usual steps when using control technology.
   1a. Define reference variables.
   1b. Create ALV Tree Control and corresponding container.
2.Create Hierarchy-header
3.Create empty Tree Control
4.Create hierarchy (nodes and leaves)
   4a. Select data
   4b. Sort output table according to your conceived hierarchy
   4c. Add data to tree
5.Send data to frontend.
6.Call dispatch to process toolbar functions
*$ADDED: begin
DATA:
  gd_del_nkey      TYPE lvc_nkey.
*$ADDED: end
§1a. Define reference variables
DATA: g_alv_tree         TYPE REF TO cl_gui_alv_tree,
      g_custom_container TYPE REF TO cl_gui_custom_container.
DATA: gt_sflight      TYPE sflight OCCURS 0,      "Output-Table
      ok_code LIKE sy-ucomm,
      save_ok LIKE sy-ucomm,           "OK-Code
      g_max TYPE i VALUE 255.
END-OF-SELECTION.
  CALL SCREEN 100.
*&      Module  PBO  OUTPUT
      process before output
MODULE pbo OUTPUT.
  SET PF-STATUS 'MAIN100'.
  SET TITLEBAR 'MAINTITLE'.
  IF g_alv_tree IS INITIAL.
    PERFORM init_tree.
    CALL METHOD cl_gui_cfw=>flush
      EXCEPTIONS
        cntl_system_error = 1
        cntl_error        = 2.
    IF sy-subrc NE 0.
      CALL FUNCTION 'POPUP_TO_INFORM'
        EXPORTING
          titel = 'Automation Queue failure'(801)
          txt1  = 'Internal error:'(802)
          txt2  = 'A method in the automation queue'(803)
          txt3  = 'caused a failure.'(804).
    ENDIF.
  ENDIF.
ENDMODULE.                             " PBO  OUTPUT
*&      Module  PAI  INPUT
      process after input
MODULE pai INPUT.
  save_ok = ok_code.
  CLEAR ok_code.
  CASE save_ok.
    WHEN 'EXIT' OR 'BACK' OR 'CANC'.
      PERFORM exit_program.
*$ADDED: begin
    WHEN 'DELETE'.
      CALL METHOD g_alv_tree->delete_subtree
        EXPORTING
          i_node_key                = gd_del_nkey
         I_UPDATE_PARENTS_EXPANDER = SPACE
          i_update_parents_folder   = 'X'
        EXCEPTIONS
          node_key_not_in_model     = 1
          OTHERS                    = 2.
      IF sy-subrc <> 0.
      MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
                 WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
      ENDIF.
      CALL METHOD g_alv_tree->frontend_update.
*$ADDED: end
    WHEN OTHERS.
§6. Call dispatch to process toolbar functions
      CALL METHOD cl_gui_cfw=>dispatch.
  ENDCASE.
  CALL METHOD cl_gui_cfw=>flush.
ENDMODULE.                             " PAI  INPUT
*&      Form  init_tree
      text
-->  p1        text
<--  p2        text
FORM init_tree.
§1b. Create ALV Tree Control and corresponding Container.
create container for alv-tree
  DATA: l_tree_container_name(30) TYPE c.
  l_tree_container_name = 'CCONTAINER1'.
  CREATE OBJECT g_custom_container
     EXPORTING
           container_name = l_tree_container_name
     EXCEPTIONS
           cntl_error                  = 1
           cntl_system_error           = 2
           create_error                = 3
           lifetime_error              = 4
           lifetime_dynpro_dynpro_link = 5.
  IF sy-subrc <> 0.
    MESSAGE x208(00) WITH 'ERROR'(100).
  ENDIF.
create tree control
  CREATE OBJECT g_alv_tree
    EXPORTING
        parent              = g_custom_container
        node_selection_mode = cl_gui_column_tree=>node_sel_mode_single
        item_selection      = 'X'
        no_html_header      = 'X'
        no_toolbar          = ''
    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.
  IF sy-subrc <> 0.
    MESSAGE x208(00) WITH 'ERROR'.                          "#EC NOTEXT
  ENDIF.
§2. Create Hierarchy-header
The simple ALV Tree uses the text of the fields which were used
for sorting to define this header. When you use
the 'normal' ALV Tree the hierarchy is build up freely
by the programmer this is not possible, so he has to define it
himself.
  DATA l_hierarchy_header TYPE treev_hhdr.
  PERFORM build_hierarchy_header CHANGING l_hierarchy_header.
§3. Create empty Tree Control
IMPORTANT: Table 'gt_sflight' must be empty. Do not change this table
(even after this method call). You can change data of your table
by calling methods of CL_GUI_ALV_TREE.
Furthermore, the output table 'gt_outtab' must be global and can
only be used for one ALV Tree Control.
  CALL METHOD g_alv_tree->set_table_for_first_display
    EXPORTING
      i_structure_name    = 'SFLIGHT'
      is_hierarchy_header = l_hierarchy_header
    CHANGING
      it_outtab           = gt_sflight. "table must be empty !
§4. Create hierarchy (nodes and leaves)
  PERFORM create_hierarchy.
§5. Send data to frontend.
  CALL METHOD g_alv_tree->frontend_update.
wait for automatic flush at end of pbo
ENDFORM.                               " init_tree
*&      Form  build_hierarchy_header
      build hierarchy-header-information
     -->P_L_HIERARCHY_HEADER  strucxture for hierarchy-header
FORM build_hierarchy_header CHANGING
                               p_hierarchy_header TYPE treev_hhdr.
  p_hierarchy_header-heading = 'Month/Carrier/Date'(300).
  p_hierarchy_header-tooltip = 'Flights in a month'(400).
  p_hierarchy_header-width = 30.
  p_hierarchy_header-width_pix = ' '.
ENDFORM.                               " build_hierarchy_header
*&      Form  exit_program
      free object and leave program
FORM exit_program.
  CALL METHOD g_custom_container->free.
  LEAVE PROGRAM.
ENDFORM.                               " exit_program
*&      Form  create_hierarchy
      text
-->  p1        text
<--  p2        text
FORM create_hierarchy.
  DATA: ls_sflight TYPE sflight,
        lt_sflight TYPE sflight OCCURS 0,
        l_yyyymm(6) TYPE c,            "year and month of sflight-fldate
        l_yyyymm_last(6) TYPE c,
        l_carrid LIKE sflight-carrid,
        l_carrid_last LIKE sflight-carrid.
  DATA: l_month_key TYPE lvc_nkey,
        l_carrid_key TYPE lvc_nkey,
        l_last_key TYPE lvc_nkey.
§4a. Select data
  SELECT * FROM sflight INTO TABLE lt_sflight UP TO g_max ROWS.
§4b. Sort output table according to your conceived hierarchy
We sort in this order:
   year and month (top level nodes, yyyymm of DATS)
     carrier id (next level)
        day of month (leaves, dd of DATS)
  SORT lt_sflight BY fldate0(6) carrid fldate6(2).
Note: The top level nodes do not correspond to a field of the
output table. Instead we use data of the table to invent another
hierarchy level above the levels that can be build by sorting.
§4c. Add data to tree
  LOOP AT lt_sflight INTO ls_sflight.
Prerequesite: The table is sorted.
You add a node everytime the values of a sorted field changes.
Finally, the complete line is added as a leaf below the last
node.
    l_yyyymm = ls_sflight-fldate+0(6).
    l_carrid = ls_sflight-carrid.
Top level nodes:
    IF l_yyyymm <> l_yyyymm_last.      "on change of l_yyyymm
      l_yyyymm_last = l_yyyymm.
*Providing no key means that the node is added on top level:
      PERFORM add_month USING    l_yyyymm
                             CHANGING l_month_key.
The month changed, thus, there is no predecessor carrier
      CLEAR l_carrid_last.
    ENDIF.
Carrier nodes:
(always inserted as child of the last month
which is identified by 'l_month_key')
    IF l_carrid <> l_carrid_last.      "on change of l_carrid
      l_carrid_last = l_carrid.
      PERFORM add_carrid_line USING    ls_sflight
                                       l_month_key
                              CHANGING l_carrid_key.
    ENDIF.
Leaf:
(always inserted as child of the last carrier
which is identified by 'l_carrid_key')
    PERFORM add_complete_line USING  ls_sflight
                                     l_carrid_key
                            CHANGING l_last_key.
  ENDLOOP.
ENDFORM.                               " create_hierarchy
*&      Form  add_month
FORM add_month  USING     p_yyyymm TYPE c
                          p_relat_key TYPE lvc_nkey
                CHANGING  p_node_key TYPE lvc_nkey.
  DATA: l_node_text TYPE lvc_value,
        ls_sflight TYPE sflight,
        l_month(15) TYPE c.            "output string for month
get month name for node text
  PERFORM get_month USING p_yyyymm
                    CHANGING l_month.
  l_node_text = l_month.
add node:
ALV Tree firstly inserts this node as a leaf if you do not provide
IS_NODE_LAYOUT with field ISFOLDER set. In form 'add_carrid_line'
the leaf gets a child and thus ALV converts it to a folder
automatically.
  CALL METHOD g_alv_tree->add_node
    EXPORTING
      i_relat_node_key = p_relat_key
      i_relationship   = cl_gui_column_tree=>relat_last_child
      i_node_text      = l_node_text
      is_outtab_line   = ls_sflight
    IMPORTING
      e_new_node_key   = p_node_key.
ENDFORM.                               " add_month
FORM add_carrid_line USING     ps_sflight TYPE sflight
                               p_relat_key TYPE lvc_nkey
                     CHANGING  p_node_key TYPE lvc_nkey.
  DATA: l_node_text TYPE lvc_value,
        ls_sflight TYPE sflight.
add node
ALV Tree firstly inserts this node as a leaf if you do not provide
IS_NODE_LAYOUT with field ISFOLDER set. In form 'add_carrid_line'
the leaf gets a child and thus ALV converts it to a folder
automatically.
  l_node_text =  ps_sflight-carrid.
  CALL METHOD g_alv_tree->add_node
    EXPORTING
      i_relat_node_key = p_relat_key
      i_relationship   = cl_gui_column_tree=>relat_last_child
      i_node_text      = l_node_text
      is_outtab_line   = ls_sflight
    IMPORTING
      e_new_node_key   = p_node_key.
ENDFORM.                               " add_carrid_line
*&      Form  add_complete_line
FORM add_complete_line USING   ps_sflight TYPE sflight
                               p_relat_key TYPE lvc_nkey
                     CHANGING  p_node_key TYPE lvc_nkey.
  DATA: l_node_text TYPE lvc_value.
  WRITE ps_sflight-fldate TO l_node_text MM/DD/YYYY.
add leaf:
ALV Tree firstly inserts this node as a leaf if you do not provide
IS_NODE_LAYOUT with field ISFOLDER set.
Since these nodes will never get children they stay leaves
(as intended).
  CALL METHOD g_alv_tree->add_node
    EXPORTING
      i_relat_node_key = p_relat_key
      i_relationship   = cl_gui_column_tree=>relat_last_child
      is_outtab_line   = ps_sflight
      i_node_text      = l_node_text
    IMPORTING
      e_new_node_key   = p_node_key.
*$ADDED: begin
  IF ( ps_sflight-fldate = '20040522' ).  " first flight date
    IF ( gd_del_nkey IS INITIAL ).  " collect only first date
      gd_del_nkey = p_node_key.
    ENDIF.
  ENDIF.
*$ADDED: end
ENDFORM.                               " add_complete_line
*&      Form  GET_MONTH
      text
     -->P_P_YYYYMM  text
     <--P_L_MONTH  text
FORM get_month USING    p_yyyymm
               CHANGING p_month.
Returns the name of month according to the digits in p_yyyymm
  DATA: l_monthdigits(2) TYPE c.
  l_monthdigits = p_yyyymm+4(2).
  CASE l_monthdigits.
    WHEN '01'.
      p_month = 'January'(701).
    WHEN '02'.
      p_month = 'February'(702).
    WHEN '03'.
      p_month = 'March'(703).
    WHEN '04'.
      p_month = 'April'(704).
    WHEN '05'.
      p_month = 'May'(705).
    WHEN '06'.
      p_month = 'June'(706).
    WHEN '07'.
      p_month = 'July'(707).
    WHEN '08'.
      p_month = 'August'(708).
    WHEN '09'.
      p_month = 'September'(709).
    WHEN '10'.
      p_month = 'October'(710).
    WHEN '11'.
      p_month = 'November'(711).
    WHEN '12'.
      p_month = 'December'(712).
  ENDCASE.
  CONCATENATE p_yyyymm+0(4) '->' p_month INTO p_month.
ENDFORM.                               " GET_MONTH
/code
Regards
  Uwe