Feildcatalog in ALV

[Former Member]

1.Why do we need REUSE_ALV_FIELDCATALOG_MERGE?

I have done a sample program which travel from first list to second list.Simple steps are:

w_program = sy-repid

1.collect data from mara and put into internal table 1.

2.Displayed report using REUSE_ALV_GRID_DISPLAY passing PICK command,callback program=w_program.

3.Get selected row using Form Pick command.....

4.Update the internal table 2,with data from makt.

5.call function REUSE_ALV_FIELDCATALOG_MERGE getting T_FIELDCAT value.

w_program = sy-repid

6.Dispaly report using REUSE_ALV_GRID_DISPLAY passing internal table 2,callbackprogram=w_program.

a)I dont understand the usage of REUSE_ALV_FIELDCATALOG_MERGE.Can anyone tell me usage of that?

b)I think Sy-repid fetches current report id.Please tell me the role of "w_program=sy-repid" in the above program.

C)I tried 3 stages report.Mara->Makt->Mard.The flow was REUSE_ALV_GRID_DISPLAY->REUSE_ALV_FIELDCATALOG_MERGE->REUSE_ALV_GRID_DISPLAY->REUSE_ALV_FIELDCATALOG->REUSE_ALV_GRID_DISPLAY

but error occured,So I removed 2nd FM(fieldcatalog)

REUSE_ALV_GRID_DISPLAY->REUSE_ALV_GRID_DISPLAY->REUSE_ALV_FIELDCATALOG->REUSE_ALV_GRID_DISPLAY

Its working now?Any suggestions

[Kanagaraja_L]

Hi Gopi,

REUSE_ALV_FIELDCATALOG_MERGE is used for retrieve a catalog structure from a table defined in the Importing paramater DB Table/Internal Table, It will Partially help to Create a Fieldcatalog.

SY-REPID is the Name of the current ABAP program, It will Identify the Main progrma after call the FM.

Kanagaraja L

[Former Member]

hi,

A field catalog is prepared using the internal table (I_FIELDCAT) of type SLIS_T_FIELDCAT_ALV. Field catalog containing descriptions of the list output fields (usually a subset of the internal output table fields).

A field catalog is required for every ALV list output to add desired functionality (i.e. Key, Hotspot, Specific headings, Justify, Col. position etc) to certain fields of the output. If not mentioned specifically, then the defaults are taken. The possible values and defaults are listed below.

The field catalog for the output table is built-up in the caller's coding. The build-up can be completely or partially automated by calling the REUSE_ALV_FIELDCATALOG_MERGE module.

The minimal field catalog is documented below. This can be done in a routine using a local variable. The user can use the other optional parameters to assign output attributes to different fields in the output, which differ from the default.

A field catalog need not be built-up and passed explicitly only under the following conditions:

1. The internal table to be output has the same structure as a Data Dictionary structure which is referred to in the internal table declaration using LIKE or INCLUDE STRUCTURE. In this case the attributes of the different fields is taken directly from the table and the attributes (key fields, length, texts etc) need to state explicitly.

2. all fields in this structure are to be output

3. The structure name is passed to ALV in the parameter I_STRUCTURE_NAME of the function module REUSE_ALV_LIST_DISPLAY.

-

---

CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'

EXPORTING

I_PROGRAM_NAME = V_REPID

• I_INTERNAL_TABNAME =

I_STRUCTURE_NAME = 'ZCRICKET'

• I_CLIENT_NEVER_DISPLAY = 'X'

• I_INCLNAME =

• I_BYPASSING_BUFFER =

• I_BUFFER_ACTIVE =

CHANGING

CT_FIELDCAT = I_FIELDCAT

EXCEPTIONS

INCONSISTENT_INTERFACE = 1

PROGRAM_ERROR = 2

OTHERS = 3

.

IF SY-SUBRC <> 0.

MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

reward if useful

rgds

Umakanth

[Former Member]

Hi,

normally we can generate field catalog by our self by

using structure 'slis_fieldcat_alv'

which have fields like fieldname , itabname, edit, do_sum...etc.

here we r generating work area and appending to internal table of type 'slis_t_fieldcat_alv' to format the data output.

2. But instead of above u can also generate fieldcatalog by using function module 'REUSE_ALV_FIELDCATALOG_MERGE' HERE

U R PASSING TWO PARAMETERS to this FM

ie.

IMPORT

u r internal table

EXPORT

fieldcatalog internal table of type slis_t_fieldcat_alv.

here output of this consist field catalog itab with format of data to display on grid or list.

then u can directly pass to FM

REUSE_ALV_GRID_DISPLAY or REUSE_ALV_LIST_DISPLAY

Edited by: vijay Mekala on Dec 31, 2007 11:31 AM

[Former Member]

I should forget that old Dinosaur way of doing it.

The method I'm showing below will work for almost ANY structure you care to name whether or not the fields are in the data dictionary.

I create a dynamic FCAT and dynamic table based on the FCAT and then populate it.

You can create field catalogs dynamically quite simply by using the new RTTI facility available from 4.6C onwards.

(From here it's only a small step to dynamic tables and EASY ALV grid displays)

Example to create dynamic FCAT and table and populate it with 200 entries from VAPMA

PROGRAM ZZ_BUILD_FLDCATALOG.
tables: vapma.
* Define any structure
types:  begin of s_elements,
  vbeln   type vapma-vbeln,
  posnr   type vapma-posnr,
  matnr   type vapma-matnr,
  kunnr   type vapma-kunnr,
  werks   type vapma-werks,
  vkorg   type vapma-vkorg,
  vkbur   type vapma-vkbur,
  status  type c,

end of  s_elements.

* end of your structure

data lr_rtti_struc type ref to cl_abap_structdescr .
data:
    zog                     like line of lr_rtti_struc->components .
  data:
    zogt                    like table of zog,
  wa_it_fldcat type lvc_s_fcat,
  it_fldcat type lvc_t_fcat ,
  dy_line            type ref to data,
  dy_table           type ref to data.


 data:  dref               type ref to data.
 field-symbols: <fs> type any,
    <dyn_table>    type  standard table,
    <dyn_wa>.


*now I want to build a field catalog
* First get your data structure into a field symbol
create data dref type s_elements.
  assign dref->* to <fs>.

  lr_rtti_struc ?= cl_abap_structdescr=>describe_by_data( <fs> ).

    zogt[]  = lr_rtti_struc->components.
 loop at zogt 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.
* Let's create a dynamic table and populate it

call method cl_alv_table_create=>create_dynamic_table
       exporting
            it_fieldcatalog = it_fldcat
       importing
            ep_table = dy_table.


assign dy_table->* to <dyn_table>.
  create data dy_line like line of <dyn_table>.
  assign dy_line->* to <dyn_wa>.

  select vbeln posnr matnr kunnr werks vkorg vkbur
         up to 200 rows
         from vapma
         into  corresponding fields of table <dyn_table>.

• from here you can pass your table to a GRID for display etc etc.

Cheers

Jimbo