Hi there!
today I doubt that I do programming for so many years...
The task: Provide an easy sorting mechanism in ALV grid.
The user should be able to mark any lines (one, a block of lines or arbitrary lines) and move them via drag and drop to another place.
I want to have a solution that can be used instead of the cl_gui_alv_grid. Therefore I inherited the class and implemented drag and drop feature.
The task seems to be quite easy: renumber the marked rows, find the new position in the data table and renumber the old entries.
May be I do think to complex or it really is not that trivial...
I would like to invite you to a challenge and try to find a working solution.
I myself had three approaches which either do not work for every selection or which use too much memory and performance.
The following code provides a demo report that
- displays table T005T (countries) in alv grid
- has a derived cl_gui_alv_grid class
- has a dragdrop-data-object class
- is prepared for dragging and dropping lines (or a single cell)
Just copy and paste the following code and try to find a simple solution that just sets the new order-id in the given field.
I am excited to see your solutions! 🙂
Enno
EXAMPLE
this is one of the most complex example: marking several lines that are not in one block and dragging them to another line:
Lines 4,6,7 and 9 are marked and are moved to line 2.
After dropping the lines the renumbering will be done and shown in field NATIO:
HINTS
It matters if you move the lines up or down.
Calculating the new order number should be preferred. I have a solution where I copy the selected lines to a temporary created identical table, deleting the marked lines, do the numbering and insertion at new position. This might be a problem in huge tables...
CODE
REPORT .
CLASS lcl_dragdrop_sort DEFINITION.
PUBLIC SECTION.
DATA at_rows TYPE lvc_t_row.
DATA ao_data TYPE REF TO data.
ENDCLASS.
CLASS lcl_gui_alv_grid_sort DEFINITION
INHERITING FROM cl_gui_alv_grid.
PUBLIC SECTION.
METHODS set_sort_field
IMPORTING
fieldname TYPE clike.
PROTECTED SECTION.
DATA mv_sort_field TYPE char30 .
CONSTANTS mc_sort_flavor TYPE c LENGTH 10 VALUE 'SortMe'.
METHODS on_drag FOR EVENT ondrag OF cl_gui_alv_grid
IMPORTING e_column e_row e_dragdropobj es_row_no sender.
METHODS on_drop FOR EVENT ondrop OF cl_gui_alv_grid
IMPORTING e_column e_row e_dragdropobj es_row_no sender.
ENDCLASS.
CLASS lcl_gui_alv_grid_sort IMPLEMENTATION.
METHOD on_drag.
DATA lo_dragdrop_sort TYPE REF TO lcl_dragdrop_sort.
lo_dragdrop_sort = NEW #( ).
sender->get_selected_rows( IMPORTING et_index_rows = lo_dragdrop_sort->at_rows ).
IF lo_dragdrop_sort->at_rows IS INITIAL.
"No lines selected: get current cell
sender->get_current_cell(
IMPORTING
e_row = DATA(lv_row) ).
IF NOT lv_row IS INITIAL.
APPEND VALUE #( index = lv_row ) TO lo_dragdrop_sort->at_rows.
ENDIF.
ENDIF.
lo_dragdrop_sort->ao_data = mt_outtab.
e_dragdropobj->object ?= lo_dragdrop_sort.
ENDMETHOD.
METHOD on_drop.
DATA lo_dragdrop_sort TYPE REF TO lcl_dragdrop_sort.
FIELD-SYMBOLS <lft_data> TYPE table.
CHECK e_dragdropobj->flavor = mc_sort_flavor.
TRY.
lo_dragdrop_sort ?= e_dragdropobj->object.
CHECK lo_dragdrop_sort->at_rows IS NOT INITIAL.
CATCH cx_sy_move_cast_error.
RETURN.
ENDTRY.
ASSIGN lo_dragdrop_sort->ao_data->* TO <lft_data>.
LOOP AT <lft_data> ASSIGNING FIELD-SYMBOL(<lfs_data>).
ASSIGN COMPONENT mv_sort_field OF STRUCTURE <lfs_data>
TO FIELD-SYMBOL(<lfv_sortn>).
CHECK sy-subrc = 0.
<lfv_sortn> = CONV numc10( sy-tabix ).
"------->
"PLACE YOUR SOLUTION HERE
"AND HERE
"...
"....AND
"------> HERE
"---------------------------------------------> SOLUTION!! <------"
ENDLOOP.
"Set sort field
me->get_sort_criteria( IMPORTING et_sort = DATA(lt_sort) ).
IF NOT line_exists( lt_sort[ fieldname = mv_sort_field ] ).
INSERT VALUE #( fieldname = mv_sort_field spos = 1 up = abap_true )
INTO lt_sort INDEX 1.
ENDIF.
"Set sorting
me->set_sort_criteria( lt_sort ).
"Show changes
refresh_table_display( ).
ENDMETHOD.
METHOD set_sort_field.
mv_sort_field = fieldname.
SET HANDLER on_drop FOR me.
SET HANDLER on_drag FOR me.
DATA(lo_dd) = NEW cl_dragdrop( ).
lo_dd->add( dragsrc = abap_true
droptarget = abap_true
flavor = mc_sort_flavor
effect = cl_dragdrop=>copy
effect_in_ctrl = cl_dragdrop=>move ).
DATA(lv_dd_handle) = 0.
lo_dd->get_handle( IMPORTING handle = lv_dd_handle ).
"Set drag-drop-handle
get_frontend_layout( IMPORTING es_layout = DATA(ls_layout) ).
ls_layout-s_dragdrop-row_ddid = lv_dd_handle.
set_frontend_layout( ls_layout ).
refresh_table_display( ).
ENDMETHOD.
ENDCLASS.
CLASS main DEFINITION.
PUBLIC SECTION.
TYPES ty_data TYPE t005t.
TYPES ty_data_t TYPE STANDARD TABLE OF ty_data
WITH DEFAULT KEY.
DATA ms_data TYPE ty_data.
DATA mt_data TYPE ty_data_t.
DATA mr_grid TYPE REF TO lcl_gui_alv_grid_sort.
METHODS start.
PROTECTED SECTION.
METHODS selection.
METHODS display.
ENDCLASS.
CLASS main IMPLEMENTATION.
METHOD selection.
SELECT * FROM t005t INTO TABLE mt_data UP TO 10 ROWS
WHERE spras = sy-langu.
ENDMETHOD.
METHOD start.
selection( ).
display( ).
ENDMETHOD.
METHOD display.
WRITE 'DUMMY'.
CREATE OBJECT mr_grid
EXPORTING
i_parent = cl_gui_container=>screen0
i_appl_events = space.
DATA lv_structure_name TYPE dd02l-tabname VALUE 'T005T'.
DATA ls_variant TYPE disvariant.
DATA lv_save TYPE char01 VALUE 'U'.
DATA lv_default TYPE char01 VALUE abap_true.
DATA ls_layout TYPE lvc_s_layo.
ls_layout-sel_mode = 'A'.
ls_layout-grid_title = 'Countries'.
mr_grid->set_table_for_first_display(
EXPORTING
i_structure_name = lv_structure_name
is_variant = ls_variant
i_save = lv_save
i_default = lv_default
is_layout = ls_layout
CHANGING
it_outtab = mt_data ).
mr_grid->set_sort_field( 'NATIO' ).
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
NEW main( )->start( ).
- SAP Managed Tags:
Just found out the following:
If ALV grid is in edit-mode then you can move the lines by default even between two lines:
but:
1. the sorting is wrong when selecting multiple "blocks" of lines
2. How can I access the event "dragging complete"? Event DATA_CHANGED does not work for dragging and dropping.
- SAP Managed Tags:
Sorry, could not post it as reply to comment above. Tried it several times.
Enno wrote:
Why did you put your last code in OnDropComplete? In this case it should also work w/o OnDropComplete...?I used OnDropComplete, because you mentioned it in your additional comment ("2. How can I access the event "dragging complete"?)
And it is inspired from paper algorithm.
Starting with initialized numbering:
On_Drap move selected lines and number them:
On_Drop move lines to new position and insert them:
On_DropComplete initialize numbering for next roundtrip:
- SAP Managed Tags:
