Definition and a Program on ALV

Give definition and a Program on ALV.

I would say that ALV is a tool that you can use in ABAP to display data in a grid - you just call a function doing it, pass the data to it and the function itself produces a nice report with many functions (like sort by, filtler etc.)

I attach a demo program, which is perfectly prepared that you change the columns to contain what you want.

There is also another way of doing the same, using the objects.

REPORT z_pj_test_reuse .


* A demo program for the function REUSE_ALV_LIST_DISPLAY


* Types that we need
TYPE-POOLS slis.


TYPES:
  BEGIN OF ts_my_item,

* This structure represents a line of our table
* You can change this structure in any way you want,
* but do not forget : you must then modify the form show_alv_grid
* to show also the new components of this structure

  m_element1 TYPE char30,
  m_element2 TYPE num5,
* If there is an element in this structure for which you do not
* insert the statement "ls_fieldcat-fieldname    = ..."
* then the element will not be displayed, for example this one:
  m_element_not_displayed TYPE char32,
  END OF ts_my_item.


TYPES : t_tab_my_item TYPE TABLE OF ts_my_item.


* After you run the program, this will be executed:
PERFORM main.


*---------------------------------------------------------------------*
*       FORM main                                                     *
*---------------------------------------------------------------------*
*       Main program
*---------------------------------------------------------------------*
FORM main.
  DATA lt_items TYPE t_tab_my_item.
  PERFORM fill_test_data USING lt_items.
  PERFORM show_alv_grid USING lt_items.
ENDFORM.



*---------------------------------------------------------------------*
*       FORM fill_test_data                                           *
*---------------------------------------------------------------------*
*       ........                                                      *
*---------------------------------------------------------------------*
*  -->  LT_ITEMS                                                      *
*---------------------------------------------------------------------*
FORM fill_test_data CHANGING lt_items TYPE t_tab_my_item.

* Here the structure will be filled with demo data
* In reality, the structure will have different components
* (those which you need)
* And will be filled with real data

  DATA ls_line TYPE LINE OF t_tab_my_item.
  CLEAR lt_items.
* First line of ALV grid
  ls_line-m_element1 = 'Some data'.
  ls_line-m_element2 = '4444'.
  ls_line-m_element_not_displayed = 'This will not be displayed'.
  APPEND ls_line TO lt_items.

* second line
  ls_line-m_element1 = 'Some other data'.
  ls_line-m_element2 = '4445'.
  APPEND ls_line TO lt_items.


* third line
  ls_line-m_element1 = 'More data'.
  APPEND ls_line TO lt_items.

ENDFORM.


**************************************************************
*   FORM show_alv_grid
*
FORM show_alv_grid    CHANGING tab_output TYPE t_tab_my_item.

  DATA: it_fieldcat TYPE slis_t_fieldcat_alv,
        gt_events      TYPE slis_t_event,
        repid LIKE sy-repid,
        ls_fieldcat TYPE slis_fieldcat_alv,
        it_layout   TYPE slis_layout_alv.

  """"""""""""""""""""""""""""""""
  " ls_fieldcat

  ls_fieldcat-tabname      = 'IT_DENIK'.    " Interní tabulka
  ls_fieldcat-ref_tabname  = 'EKKO'.       " Pùvodní tabulka.

* The following three lines must be here for each element
* that we want to display
* The fieldname must be in capital letters

  ls_fieldcat-fieldname    = 'M_ELEMENT1'.
  ls_fieldcat-reptext_ddic = 'Title of 1st column'.
  APPEND ls_fieldcat TO it_fieldcat.

  ls_fieldcat-fieldname    = 'M_ELEMENT2'.
  ls_fieldcat-reptext_ddic = 'Title of 2nd column'.
  APPEND ls_fieldcat TO it_fieldcat.

* I purpochasely ommited the element m_element_not_displayed
* Therefore it will not be displayed

  """"""""""""""""""""""""""""""""
  " it_layout

* There is a lot of code which I do not understand
* You can write some strings there and watch where on the screen
* they will appear.

  CLEAR it_layout.
  it_layout-detail_popup = ' '.
  it_layout-detail_titlebar = ' '."Detail of the window (?)
  it_layout-info_fieldname = ' '.
  it_layout-header_text = 'Our title'.
  it_layout-no_colhead = ' '.
          "'X' cancels headlines of columns
  it_layout-no_hotspot = ' '.
    "'X' = cannot select a column
  it_layout-window_titlebar = it_layout-header_text.
  it_layout-list_append = ' '.
  it_layout-item_text = ' '.

  """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
  " call REUSE_ALV_LIST_DISPLAY


  repid = sy-repid.
  CALL FUNCTION 'REUSE_ALV_LIST_DISPLAY'
       EXPORTING
            i_callback_program = repid
            it_fieldcat        = it_fieldcat
            it_events          = gt_events[]
            is_layout          = it_layout
       TABLES
            t_outtab           = tab_output.
ENDFORM.