Dynamic tables in ALV with RTTI

Dear all,

In this blog an example of dynamic tables in an ALV with RTTI is showed.

RTTI stands for Run Time Type Identification. It's used to get the definition of existing variables or existing types.

This can be used to create a dynamic structure and table type at runtime. These structure can easily change.

The next example have twoo screens:

• One to give a name of an SAP table in parameter.
• One to show all the values in the ALV with the given table from previous screen.

Below an example of a dynamic ALV with RTTI (code)

All the data that will be used.

TYPE-POOLS : abap, slis.
FIELD-SYMBOLS: <fs_table> TYPE STANDARD TABLE,                <fs_wa>,                <fs_field>.
DATA: zdyn_table    TYPE REF TO data,       zdyn_line     TYPE REF TO data,       zwa_fieldcat  TYPE lvc_s_fcat,       zit_fieldcat  TYPE lvc_t_fcat.
*ALV data declarations
DATA: zfieldcatalog  TYPE slis_t_fieldcat_alv WITH HEADER LINE,       zgd_tab_group  TYPE slis_t_sp_group_alv,       zgd_layout     TYPE slis_layout_alv,       zgd_repid      LIKE sy-repid.
PARAMETERS: zp_table(30) TYPE c .
DATA : zit_tabdescr TYPE abap_compdescr_tab,        zwa_tabdescr TYPE abap_compdescr.
DATA : zref_table_descr TYPE REF TO cl_abap_structdescr.

Return structure of the filled parameter. ZIT_TABDESCR[] will now have the structure and details (datatype, decimals, ... ) from the table.

zref_table_descr ?= cl_abap_typedescr=>describe_by_name( zp_table ).
zit_tabdescr[] = zref_table_descr->components[].

Set the structure of the table in the FIELDCAT, the structure of the ALV is based on this.

LOOP AT zit_tabdescr INTO zwa_tabdescr.   CLEAR zwa_fieldcat.   zwa_fieldcat-fieldname = zwa_tabdescr-name .   zwa_fieldcat-datatype  = zwa_tabdescr-type_kind.   zwa_fieldcat-inttype   = zwa_tabdescr-type_kind.   zwa_fieldcat-intlen    = zwa_tabdescr-length.   zwa_fieldcat-decimals  = zwa_tabdescr-decimals.   APPEND zwa_fieldcat TO zit_fieldcat.
ENDLOOP.

Create dynamic internal table and assign to Field Symbol

CALL METHOD cl_alv_table_create=>create_dynamic_table   EXPORTING     it_fieldcatalog = zit_fieldcat   IMPORTING     ep_table        = zdyn_table.
ASSIGN zdyn_table->* TO <fs_table>.

Create dynamic work area and assign to Field Symbol

CREATE DATA zdyn_line LIKE LINE OF <fs_table>.
ASSIGN zdyn_line->* TO <fs_wa>.

When the dynamic table is setted up, this one can be filled with an SELECT statement. It gets all the values from the filed parameter.

SELECT * INTO CORRESPONDING FIELDS OF TABLE  <fs_table>
FROM (zp_table).

An ALV Function module to build field catalog from the dynamic created table.

DATA: zit_fcat  TYPE slis_t_fieldcat_alv.
CALL FUNCTION 'REUSE_ALV_FIELDCATALOG_MERGE'   EXPORTING     i_structure_name       = zp_table   CHANGING     ct_fieldcat            = zit_fcat   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.

Fieldcatalog is moved to a new fieldcatalog

zfieldcatalog[] =  zit_fcat[].

To optimize every field length:

zgd_layout-colwidth_optimize = 'X'.

The ALV will be showed with the next function module. Layout, fieldcatalog and repid are given in EXPORTING, also the table with al the values.

zgd_repid = sy-repid.
CALL FUNCTION 'REUSE_ALV_GRID_DISPLAY'   EXPORTING     i_callback_program = zgd_repid     is_layout          = zgd_layout     it_fieldcat        = zfieldcatalog[]     i_save             = 'X'   TABLES     t_outtab           = <fs_table>   EXCEPTIONS     program_error      = 1
OTHERS             = 2.

Kind regards,

Pieter Lemaire