EASY General Class for structure of ITAB / dynamic ITAB / FCAT

Question

Hi Guys.
Seeing all the convoluted posts about Dynamic ITABS, getting the structure of ANY ITAB (whether or not it's in the dictionary) building Dynamic FCATS etc. I'm actually very puzzled as the whole concept is CHILDISHLY SIMPLE.
If you model this code here then you can use this for ANY ITAB, DYNAMIC TABLE and FCAT you care to name and it's only a few lines of code.
The bits you can use in almost any program are shown <b>in BOLD</b>
Program  ZGENTABCREATE.
<b>FIELD-SYMBOLS :
  <fs1>  type any,
  <fs2>  type standard table,
  <dyn_table> type standard table,</b> 
  <dyn_field>,
  <dyn_wa>.
<b>CLASS zcl_dog DEFINITION.
PUBLIC SECTION.
METHODS:
return_structure,   "returns structure of ANY table
create_dynamic_fcat   "Create dynamic FCAT
       EXPORTING  it_fldcat TYPE lvc_t_fcat.
PRIVATE SECTION.
DATA:
       lr_rtti_struc TYPE REF TO cl_abap_structdescr,        "RTTI
       zog LIKE LINE OF lr_rtti_struc->components,           "RTTI
        wa_it_fldcat       TYPE lvc_s_fcat.
TYPES: struc like zog.
DATA: : zogt type table of struc.
ENDCLASS.
CLASS zcl_dog IMPLEMENTATION.
METHOD return_structure.
lr_rtti_struc ?= cl_abap_structdescr=>describe_by_data( <fs1> ).
zogt[]  = lr_rtti_struc->components.
assign zogt[] to <fs2>.
ENDMETHOD.
METHOD create_dynamic_fcat.
    LOOP AT <fs2>  INTO zog.
      CLEAR wa_it_fldcat.
      wa_it_fldcat-fieldname = zog-name .
      wa_it_fldcat-datatype = zog-type_kind.
      wa_it_fldcat-inttype = zog-type_kind.
      wa_it_fldcat-intlen = zog-length.
      wa_it_fldcat-decimals = zog-decimals.
      wa_it_fldcat-coltext = zog-name.
      wa_it_fldcat-lowercase = 'X'.
      APPEND wa_it_fldcat TO it_fldcat .
    ENDLOOP.
  ENDMETHOD.
ENDCLASS.</b>
start of program data to demo use of above class ****
INCLUDE  <icon>.
TABLES : kna1.
TYPES:  BEGIN OF s_elements,   "Any old ITAB   define structure
  kunnr   TYPE kna1-kunnr,
  name1   TYPE kna1-name1,
  stras   TYPE kna1-stras,
  telf1   TYPE kna1-telf1,
  ort01   TYPE kna1-ort01,
  pstlz   TYPE kna1-pstlz,
END OF  s_elements.
DATA:  <b>z_object type ref to zcl_dog,  "Instantiate our class
       t_elements   TYPE TABLE OF s_elements, "refers to our ITAB
       wa_elements   TYPE s_elements,    "Structure definition
       wa_dyn_table_line TYPE REF TO DATA,
       it_fldcat TYPE lvc_t_fcat,</b> 
       dy_table TYPE REF TO data,
start-of-selection.
<b>assign  wa_elements  to <fs1>.
This is IMPORTANT. Your ITAB structure must
be assigned to <fs1> which will be
used in the return_structure method.
The internal structure definition (field-names)
will be returned in <fs2> which is used for
dynamically building the field catalog.
You only need this section to get your
structure build your FCAT
and create the dynamic table
If you want to see the actual structure of
your table or how the FCAT looks
the field_symbols <fs1> and <fs2> have
the data in them.
Get variable structure names.
<b>create object
         z_object.
   call method z_object->return_structure.
build fcat.
CALL METHOD z_object->create_dynamic_fcat
      IMPORTING
        it_fldcat = it_fldcat.
build dynamic table
CALL METHOD cl_alv_table_create=>create_dynamic_table
    EXPORTING
      it_fieldcatalog = it_fldcat
    IMPORTING
      ep_table        = dy_table.</b>
Now fill and display it
You can use it in a GRID or whatever.</b>
ASSIGN dy_table->* TO <dyn_table>.
Create dynamic work area and assign to FS
  CREATE DATA dy_line LIKE LINE OF <dyn_table>.
  ASSIGN dy_line->* TO <dyn_wa>.
fill it
perform populate_dynamic_itab.
end-of-selection.
end of main logic ***************
FORM populate_dynamic_itab.
just read 200 lines as a demo from KNA1
assign dynamic table created to <field symbol>
so you can fill it with data.
  SELECT kunnr name1 stras telf1 ort01 pstlz
       UP TO 200 rows
       FROM KNA1
       INTO  CORRESPONDING FIELDS OF TABLE <dyn_table>.
      LOOP AT <dyn_table> INTO <dyn_wa>.
    DO.
      ASSIGN COMPONENT  sy-index
         OF STRUCTURE <dyn_wa> TO <dyn_field>.
      IF sy-subrc <> 0.
        EXIT.
      ENDIF.
      IF sy-index = 1.
        WRITE:/ <dyn_field>.
      ELSE.
        WRITE: <dyn_field>.
      ENDIF.
    ENDDO.
  ENDLOOP.
ENDFORM.
********************END OF CODE***********
Now NOBODY should have any probs with this stuff.
Simple   isn't it.
Cheers
and have fun.
Jimbo

Answer 1

Hi Shinjan,
One of the ways to achieve this is by creating ranges. Try this code,
TABLES: dbtab2.
FIELD-SYMBOLS: <l_line>  TYPE ANY,
                           <l_field> TYPE ANY.
DATA: new_line  TYPE REF TO data.
RANGES: r_f1 FOR dbtab2-f1. "Create ranges for the particular field say f1
"Creating work area for your dynamic int table
CREATE DATA new_line LIKE LINE OF <fs_itab>.
ASSIGN new_line->* TO <l_line> .
LOOP AT <fs_itab> ASSIGNING <l_line>.
  ASSIGN COMPONENT 'F1' OF STRUCTURE <l_line> TO <l_field>. "Now <l_field> contains the value
"Append the range from the values in dynamic tab
  r_f1-sign = 'I'.
  r_f1-option = 'EQ'.
  r_f1-low = <l_field>.
  APPEND r_f1.
ENDLOOP.
SELECT *
FROM dbtab2
INTO t_dbtab2
WHERE f1 IN r_f1. "write the select query using the ranges
Hope this helps you.
Regards,
Manoj Kumar P