ABAP OOP example and invitation

Question

For quite a while, I've been trying to learn more about ABAP OOP. But, I've
found many of the examples on the web, and in SAP provided articles, either
difficult to understand or outright lame. They never seemed to illustrate
much of what a staff ABAP programmer is called upon to do.
So, last week I decided to take the problem head on and see if I could come
up with something we all could use as a starting point to learn more about
ABAP objects.
Here's a chunk of code that I want everybody to pick apart, critique,
modify, append or whatever. The only stipulation is that you post your
suggestions back to this forum. Maybe after we get some nice ABAP objects
together, the forum manager can put them into an OOP area of this website.
================================================================
The first object I created uses the MARC (Plant Data for Material) table.
I wanted to use it to learn more about how "Selection Sets" can be used with
ABAP OOP.
The class has five methods:
-o- constructor
-o- return_marc_table
-o- return_subset_marc_table
-o- length
-o- write_marc_table
This class isn't, really, very useful. But, it does show how selection-sets
can be used with ABAP oop. The code is studded with commented BREAK-POINTS
that you can turn on and off to examine things.
Split the code into two files: Main program and Top include. Look at the
initialization section and you should be able to see how you can tweak
the materials selected for your environment.
enjoy
[email protected]
REPORT zejb_oop_sel_set2 .
This program is designed to demonstrate passing selection sets
to an ABAP object
The program has some educational value. But, other than that
probably isn't of much use.
=========================================== Main Program - BEGIN
INCLUDE zejb_oop_sel_set2_top.      "data and class definitions
SELECT-OPTIONS:
  s_matnr FOR marc-matnr,
  s_werks FOR marc-werks.
DATA: my_marc TYPE REF TO marc_object .
============================================= START-OF-SELECTION
START-OF-SELECTION.
  matnr_selector[] = s_matnr[] .
  werks_selector[] = s_werks[].
call the constructor table and create the CLASS-DATA
  CREATE OBJECT my_marc
    EXPORTING
      s_matnr  = matnr_selector
      s_werks  = werks_selector .
================================================ END-OF-SELECTION
END-OF-SELECTION.
  CALL METHOD my_marc->return_marc_table
    IMPORTING
      return_marc = tb_marc.
BREAK-POINT. " inspect tb_marc
  CALL METHOD my_marc->length
    IMPORTING
      table_size = zzlines.
  WRITE:/ 'Class-Data table in object my_marc has '
           , zzlines , ' lines'.
  ULINE.
  WRITE:/ 'printing internal table tb_marc'.
  CALL METHOD my_marc->write_marc_table
    EXPORTING
      print_table = tb_marc.
  SKIP.
BREAK-POINT.
  examine matnr_subset_selector
  examine werks_subset_selector
  CALL METHOD my_marc->return_subset_marc_table
    EXPORTING
      s_matnr     = matnr_subset_selector
      s_werks     = werks_subset_selector
    IMPORTING
      return_marc = tb_subset_marc.
BREAK-POINT.
  examine tb_subset_marc
  ULINE.
  WRITE:/ 'printing internal table tb_subset_marc'.
  CALL METHOD my_marc->write_marc_table
    EXPORTING
      print_table = tb_subset_marc.
  ULINE.
================================================== INITIALIZATION
INITIALIZATION.
  DEFINE range_append.                                      "#EC *
1 == range_name
    clear &1.                                               "#EC *
    &1-sign = &2.                                           "#EC *
    &1-option = &3.                                         "#EC *
    &1-low = &4.                                            "#EC *
    &1-high = &5.                                           "#EC *
    append &1. clear &1.                                    "#EC *
  END-OF-DEFINITION.                                        "#EC *
  DEFINE fill_range.                                        "#EC *
1 == range_name
    clear &1.                                               "#EC *
    &1-sign = &2.                                           "#EC *
    &1-option = &3.                                         "#EC *
    &1-low = &4.                                            "#EC *
    &1-high = &5.                                           "#EC *
  END-OF-DEFINITION.                                        "#EC *
modify these materials and plants to suit your environment
or create a selection variant
  range_append s_matnr 'I' 'EQ' 'HAP100' space.
  range_append s_matnr 'I' 'EQ' 'HAP205' space.
  range_append s_matnr 'I' 'EQ' 'HAP221' space.
  range_append s_matnr 'I' 'EQ' 'HAP240' space.
  range_append s_matnr 'I' 'EQ' 'HAP245' space.
  range_append s_matnr 'I' 'EQ' 'HAP250' space.
  range_append s_matnr 'I' 'EQ' 'HAP260' space.
  range_append s_werks 'I' 'EQ' '1000' space.
  range_append s_werks 'I' 'EQ' '1020' space.
fill subset selector
  fill_range st_matnr_selector 'I' 'EQ' 'HAP205' space.
  APPEND st_matnr_selector TO matnr_subset_selector.
  fill_range st_matnr_selector 'I' 'EQ' 'HAP250' space.
  APPEND st_matnr_selector TO matnr_subset_selector.
  fill_range st_werks_selector 'I' 'EQ' '1000' space.
  APPEND st_werks_selector TO werks_subset_selector.
============================================ Main Program - End
*&  Include           ZEJB_OOP_SEL_SET2_TOP                       *
============================================ Top include - BEGIN
TABLES : marc.
DATA: tb_marc TYPE TABLE OF marc,
      tb_subset_marc TYPE TABLE OF marc,
      st_marc TYPE marc.                                    "#EC *
"^^^^^^^ to/from structure. use as needed
DATA: st_matnr_selector TYPE range_s_matnr,
st_werks_selector TYPE range_werks,
matnr_selector TYPE TABLE OF range_s_matnr,
werks_selector TYPE TABLE OF range_werks,
matnr_subset_selector TYPE TABLE OF range_s_matnr,
werks_subset_selector TYPE TABLE OF range_werks.
DATA: zzlines TYPE i. " size of class_data table.
      CLASS marc_object DEFINITION
NOTE: for those new to abap objects, EVERYTHING in abap OOP
      must be explicitly "TYPED". more on this as I go along
CLASS marc_object DEFINITION.
  PUBLIC SECTION.
    TYPES:
      typ_marc TYPE TABLE OF marc,
      typ_matnr_selector TYPE TABLE OF range_s_matnr,
      typ_werks_selector TYPE TABLE OF range_werks.
    DATA: return_marc TYPE typ_marc,
          print_table TYPE typ_marc.
    CLASS-DATA:
      class_marc
        TYPE typ_marc. " <== inside public area
    ^^^^^^^ this table will be available to all methods
    ^^^^^^^ in the class
    METHODS:
      constructor
        IMPORTING
          s_matnr  TYPE typ_matnr_selector
          s_werks  TYPE typ_werks_selector OPTIONAL ,
      return_marc_table
        EXPORTING return_marc TYPE typ_marc ,
      return_subset_marc_table
        IMPORTING
          s_matnr  TYPE typ_matnr_selector
          s_werks  TYPE typ_werks_selector OPTIONAL
        EXPORTING
          return_marc TYPE typ_marc,
      length EXPORTING table_size TYPE i,
      write_marc_table
        IMPORTING print_table TYPE typ_marc.
  PROTECTED SECTION.
  PRIVATE SECTION.
ENDCLASS.                    "marc_object DEFINITION
*EJECT
      CLASS zget_sales_order_change IMPLEMENTATION
CLASS marc_object IMPLEMENTATION.
  METHOD constructor .
    DATA:
      s_lcl_matnr TYPE TABLE OF  range_s_matnr ,
      s_lcl_werks TYPE TABLE OF  range_werks .
    s_lcl_matnr[] = s_matnr[] .
    s_lcl_werks[] = s_werks[] .
    SELECT * FROM marc
      APPENDING TABLE class_marc
      WHERE matnr IN s_lcl_matnr
        AND werks IN s_lcl_werks.
    SORT class_marc BY matnr werks.
   BREAK-POINT.
  ENDMETHOD.                    "xxx
  METHOD return_marc_table.
    return_marc[] = class_marc[] .
   BREAK-POINT. " examine class_marc
  ENDMETHOD.                    "return_marc table
  METHOD        return_subset_marc_table.
    DATA: st_marc TYPE marc.
    REFRESH return_marc.
    LOOP AT class_marc INTO st_marc
      WHERE matnr IN s_matnr
        AND werks IN s_werks  .
      APPEND st_marc TO return_marc.
    ENDLOOP.
   BREAK-POINT. " examine return_marc
  ENDMETHOD.                    "return_subset_marc_table
  METHOD length.
    DESCRIBE TABLE class_marc LINES  table_size.
  ENDMETHOD.                    "length
  METHOD write_marc_table.
    DATA: st_marc TYPE marc.
    LOOP AT print_table INTO st_marc.
      WRITE:/ 'Material ' , st_marc-matnr,
      'Plant ' , st_marc-werks.
    ENDLOOP.
  ENDMETHOD.                    "write_marc_table
ENDCLASS.                    "marc_object IMPLEMENTATION
============================================== Top include - END

Answer 1

Search using " ALV Factory methods" u'll get lots of material.
for instance u can a look at this wiki
https://www.sdn.sap.com/irj/sdn/wiki?path=/display/abap/abap%2b-%2bdeveloping%2binteractive%2balv%2breport%2busing%2booabap
https://www.sdn.sap.com/irj/sdn/wiki?path=/display/community/object%2bmodel%2balv%2b-%2binteractive
[ALVOO PDF|https://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/cda3992d-0e01-0010-90b2-c4e1f899ac01]