Field catalog in ALV

Field catalog containing descriptions of the list output fields. You can use fields of the catalog to determine the number format and column properties of the list to be displayed.

The field catalog contains more than 60 fields, some of which are only used internally. The field catalog is defined in the Data Dictionary through table type LVC_T_FCAT.

We can get field description by calling function module REUSE_ALV_FIELDCATALOG_MERGE. You can see the sample in my post about Simple ALV Report.

In general case, we only use few field to describe output field.
To make it easier I use this form:

FORM f_alv_fieldcatg USING
fu_types "internal table name
fu_fname "Field name of internal table field
fu_reftb "reference table name
fu_refld "reference table field
fu_noout "X= No out
fu_outln "out
fu_fltxt "output length
fu_dosum "X=Do sum (total)
fu_hotsp "X=hotspot on
fu_just. "Justification:L,R,C

CLEAR: t_fieldcat.
t_fieldcat-tabname = fu_types.
t_fieldcat-fieldname = fu_fname.
t_fieldcat-ref_tabname = fu_reftb.
t_fieldcat-ref_fieldname = fu_refld.
t_fieldcat-no_out = fu_noout.
t_fieldcat-outputlen = fu_outln.
t_fieldcat-seltext_l = fu_fltxt.
t_fieldcat-seltext_m = fu_fltxt.
t_fieldcat-seltext_s = fu_fltxt.
t_fieldcat-reptext_ddic = fu_fltxt.
t_fieldcat-no_out = fu_noout.
t_fieldcat-do_sum = fu_dosum.
t_fieldcat-hotspot = fu_hotsp.
t_fieldcat-just = fu_just.
APPEND t_fieldcat.
CLEAR t_fieldcat.
ENDFORM. " f_alv_fieldcatg

We can use it in two way:
1. refer to data dictionary:

PERFORM f_alv_fieldcatg USING 'T_REPORT' :
'EQUNR' 'EQUI' 'EQUNR' '' '' '' '' 'X' '',
'SPART' 'VBAK' 'SPART' '' '' '' '' '' ''.

2. or define yourself

PERFORM f_alv_fieldcatg USING 'T_REPORT' :
'FIELD1' '' '' '' '20' 'Text Field1' '' '' ''.

and for field with type number, I use this:

*&---------------------------------------------------------------------*
*& Form f_alv_fieldcatg_number
*&---------------------------------------------------------------------*
* text
*----------------------------------------------------------------------*
FORM f_alv_fieldcatg_number USING fu_types
fu_fname
fu_noout
fu_outln
fu_no_sign
fu_no_zero
fu_fltxt
fu_dosum
fu_exponent
fu_decimals_out.

CLEAR: t_fieldcat.
t_fieldcat-tabname = fu_types.
t_fieldcat-fieldname = fu_fname.
t_fieldcat-no_out = fu_noout.
t_fieldcat-outputlen = fu_outln.
t_fieldcat-seltext_l = fu_fltxt.
t_fieldcat-seltext_m = fu_fltxt.
t_fieldcat-seltext_s = fu_fltxt.
t_fieldcat-reptext_ddic = fu_fltxt.
t_fieldcat-no_zero = fu_no_zero.
t_fieldcat-no_sign = fu_no_sign.
t_fieldcat-exponent = fu_exponent.
t_fieldcat-decimals_out = fu_decimals_out.
t_fieldcat-do_sum = fu_dosum.
t_fieldcat-datatype = 'FLTP'.
APPEND t_fieldcat.
CLEAR t_fieldcat.


ENDFORM. " f_alv_fieldcatg_number

For field currency, there are two options, fixed currency or variable currency.

*&---------------------------------------------------------------------*
*& Form f_alv_fieldcatg_curr
*&---------------------------------------------------------------------*
* text
*----------------------------------------------------------------------*
FORM f_alv_fieldcatg_curr USING fu_types
fu_fname
fu_reftb
fu_refld
fu_noout
fu_outln
fu_fltxt
fu_dosum
fu_hotsp
fu_cfield.

CLEAR: t_fieldcat.
t_fieldcat-tabname = fu_types.
t_fieldcat-fieldname = fu_fname.
t_fieldcat-ref_tabname = fu_reftb.
t_fieldcat-ref_fieldname = fu_refld.
t_fieldcat-no_out = fu_noout.
t_fieldcat-outputlen = fu_outln.
t_fieldcat-seltext_l = fu_fltxt.
t_fieldcat-seltext_m = fu_fltxt.
t_fieldcat-seltext_s = fu_fltxt.
t_fieldcat-reptext_ddic = fu_fltxt.
t_fieldcat-do_sum = fu_dosum.
t_fieldcat-hotspot = fu_hotsp.
t_fieldcat-cfieldname = fu_cfield.
t_fieldcat-ctabname = fu_types.
t_fieldcat-no_zero = 'X'.
APPEND t_fieldcat.
CLEAR t_fieldcat.

ENDFORM. " F_FIELDCATG_CURR

*&---------------------------------------------------------------------*
*& Form f_alv_fieldcatg_curr
*&---------------------------------------------------------------------*
* text
*----------------------------------------------------------------------*
FORM f_alv_fieldcatg_curr_fixed USING fu_types
fu_fname
fu_reftb
fu_refld
fu_noout
fu_outln
fu_fltxt
fu_dosum
fu_hotsp
fu_curr.

CLEAR: t_fieldcat.
t_fieldcat-tabname = fu_types.
t_fieldcat-fieldname = fu_fname.
t_fieldcat-ref_tabname = fu_reftb.
t_fieldcat-ref_fieldname = fu_refld.
t_fieldcat-no_out = fu_noout.
t_fieldcat-outputlen = fu_outln.
t_fieldcat-seltext_l = fu_fltxt.
t_fieldcat-seltext_m = fu_fltxt.
t_fieldcat-seltext_s = fu_fltxt.
t_fieldcat-reptext_ddic = fu_fltxt.
t_fieldcat-do_sum = fu_dosum.
t_fieldcat-hotspot = fu_hotsp.
* t_fieldcat-cfieldname = fu_cfield.
* t_fieldcat-ctabname = fu_types.
t_fieldcat-datatype = 'CURR'.
t_fieldcat-currency = fu_curr.
t_fieldcat-no_zero = 'X'.
APPEND t_fieldcat.
CLEAR t_fieldcat.

ENDFORM. " F_FIELDCATG_CURR