Purpose of the declaring the below type u0096 pools ?

Question

Hi All,
What is the Purpose of the declaring the below type – pools in the program. Why we need type-pools in the program.
TYPE-POOLS: SLIS,
GSETC.
Akshitha.

Answer 1

type pool  slis
Type-pools is a place where u can store the type declarations globally which can be used in your ABAP program. Type-pools SLIS Stores all the ALV related Type definitions.
example
For example when you create an ALV program, all types you need to use are defined in types pool SLIS.
The objects that you don't want to create in SE11 but want a single place where you can declare them together will be done in TYPE POOLs. The best example is SLIS where you have declared all the TYPES that are required to execute a ALV REPORT using the REUSE functions.
In this way you define your types only once and then you can use them everytime you need:
TYPE-POOLS SLIS.
DATA: GT_FIELDCAT TYPE SLIS_T_FIELDCAT_ALV.
The type SLIS_T_FIELDCAT_ALV is defined in type pools SLIS.
type pool gsetc
.GSETC type pool stores codes for differenct group classes
   i.e. gsetc_costcenter_setclass = '0101'
example
*& Report  ZCCGROUP_HIER                                               *
REPORT ZCCGROUP_HIER.
GSETC type pool stores codes for differenct group classes
   i.e. gsetc_costcenter_setclass = '0101'.
TYPE-POOLS: gsetc. "
TYPES: gseth_node_line    LIKE grpobjects,
       gseth_node_tab     TYPE gseth_node_line OCCURS 0.
TYPES: gseth_val_line     LIKE grpvalues,
       gseth_val_tab      TYPE gseth_val_line OCCURS 0.
TYPES: GSETH_MD_LINE      LIKE GRPMDLINE,
       GSETH_MD_TAB       TYPE GSETH_MD_LINE OCCURS 0.
DATA: it_nodes            TYPE  gseth_node_tab,
      it_values           TYPE  gseth_val_tab,
      it_mdtab            type gseth_md_tab,
      wa_mdtab            type GSETH_MD_LINE.
DATA: ld_setid            TYPE sethier-setid,
      ld_info             LIKE grphinfo,
      ld_overwrite        LIKE sy-datar.
PARAMETERS: p_ksgru  LIKE rksb1-ksgru,
            p_burks       TYPE bseg-BUKRS.
CONCATENATE gsetc_costcenter_setclass p_burks p_ksgru INTO ld_setid.
CALL FUNCTION 'K_HIERARCHY_TABLES_READ'
  EXPORTING
    e_class                           = gsetc_costcenter_setclass
                                                 "from gsetc type-pool
    e_setid                           = ld_setid
    e_kokrs                           = p_burks "company code
    E_MANDT                           = sy-mandt
    E_MASTER_DATA                     = 'XXX'
displays popup to confirm if a large amount of data is to be retrieved
    E_STRUCTURE                       = 'X  X0200'  "displays popup to confirm
    E_REPLACE_CLASS                   =
    E_REPLACE_UNIT                    =
    E_REPLACE_TABLE                   = ' '
    E_REPLACE_FIELD                   = ' '
    E_SUFFIX                          =
    E_OLD_LINE_LEVEL                  = 0
  IMPORTING
    I_DOUBLE_CHECK                    =
    I_MASTER_DATA                     =
  TABLES
    t_nodes                           = it_nodes
    t_values                          = it_values
    T_MASTER_DATA                     = it_mdtab
    T_FORMULA                         =
    T_FIELD_INFO                      =
    T_NODE_LIST_OVERWRITE             =
  CHANGING
    c_info                            = ld_info
    c_overwrite                       = ld_overwrite
EXCEPTIONS
   no_controlling_area               = 1
   no_chart_of_account               = 2
   different_controlling_areas       = 3
   different_chart_of_accounts       = 4
   set_not_found                     = 5
   illegal_field_replacement         = 6
   illegal_table_replacement         = 7
   fm_raise                          = 8
   convert_error                     = 9
   no_overwrite_standard_hier        = 10
   no_bukrs_for_kokrs                = 11
   OTHERS                            = 12.
BREAK-POINT.
An alternative function module can be found below which
is slightly easier to code but there is no direct link between
the hier and the val tables, it is just based on there
index possition.
*types : begin of T_SETHIER.
  include STRUCTURE  SETHIER_CO.
*types: end of t_sethier.
*data: it_SETHIER type standard table of t_SETHIER.
*types : begin of T_SETVAL.
  include STRUCTURE  SETVAL_CO.
*types: end of t_SETVAL.
*data: it_SETVAL type standard table of t_SETVAL.
*CALL FUNCTION 'K_GROUP_REMOTE_READ'
EXPORTING
   setclass         = gsetc_costcenter_setclass "from gsetc type-pool
   CO_AREA          = 'UNIV'
  CHRT_ACCTS       =
   groupname        =  p_ksgru
  LANGUAGE         =
IMPORTING
  RETURN           =
tables
   et_sethier       = it_SETHIER
   ET_SETVAL        = it_SETVAL.
Do reward if  helpful