sort table of objects by object attribute

[Former Member]

Hi all,

I would like to write method for sorting table of objects. Sorting will be according selected attribute of object.

My problem is that when I have dynamic data, I'm not able to access attributes of object. Here is example in code. Problematic lines are commented.
If you have any idea how to solve it, I will be very happy.

CLASS lcl_reflection DEFINITION CREATE PUBLIC.

  PUBLIC SECTION.

    CLASS-METHODS: sort_object_table_by_field IMPORTING field_name   TYPE char72

                                                        direction    TYPE c DEFAULT 'A'

                                              CHANGING  object_table TYPE table.

ENDCLASS.                    "lcl_reflection DEFINITION

CLASS lcl_reflection IMPLEMENTATION.

  METHOD sort_object_table_by_field.

    DATA: obj_type_desc   TYPE REF TO cl_abap_refdescr,

          cls_type_desc   TYPE REF TO cl_abap_classdescr,

          tab_type_desc   TYPE REF TO cl_abap_tabledescr,

          elm_type_desc   TYPE REF TO cl_abap_elemdescr,

          struc_type_desc TYPE REF TO cl_abap_structdescr,

          line            TYPE REF TO data,

          tab             TYPE REF TO data,

          object          TYPE REF TO data,

          lt_component TYPE cl_abap_structdescr=>component_table,

          ls_component LIKE LINE OF lt_component.

    FIELD-SYMBOLS: <object> TYPE any,

                   <tab>    TYPE table,

                   <line>   TYPE any,

                   <value>  TYPE any.

    READ TABLE object_table INDEX 1 ASSIGNING <object>.

    cls_type_desc ?= cl_abap_classdescr=>describe_by_object_ref( <object> ).

    elm_type_desc ?= cls_type_desc->get_attribute_type( field_name ).

    obj_type_desc ?= cl_abap_refdescr=>create( cls_type_desc ).

    UNASSIGN <object>.

    ls_component-name = 'key'.

    ls_component-type = elm_type_desc.

    APPEND ls_component TO lt_component.

    ls_component-name = 'object'.

    ls_component-type ?= obj_type_desc.

    APPEND ls_component TO lt_component.

    struc_type_desc ?= cl_abap_structdescr=>create( lt_component ).

    tab_type_desc ?= cl_abap_tabledescr=>create( p_line_type  = struc_type_desc

                                                 p_table_kind = cl_abap_tabledescr=>tablekind_std

                                                 p_unique     = abap_false ).

    REFRESH lt_component.

    CLEAR ls_component.

    CREATE DATA line TYPE HANDLE struc_type_desc.

    CREATE DATA tab TYPE HANDLE tab_type_desc.

    CREATE DATA object TYPE HANDLE obj_type_desc.

    ASSIGN tab->* TO <tab>.

    ASSIGN line->* TO <line>.

    ASSIGN object->* TO <object>.

    LOOP AT object_table REFERENCE INTO object.

      APPEND INITIAL LINE TO <tab> REFERENCE INTO line.

      ASSIGN object->* TO <value>.

      ASSIGN line->* TO <line>.

*      <line>-key = <value>->(field_name).

*      <line>-object = object.

    ENDLOOP.

*    SORT <tab> BY key.

*    LOOP AT <tab> REFERENCE INTO line.

*      APPEND INITIAL LINE TO object_table REFERENCE INTO object.

*      object = line-object.

*    ENDLOOP.

  ENDMETHOD.                    "sort_object_table_by_field

ENDCLASS.                    "lcl_reflection IMPLEMENTATION

[gaurab_banerji]

Not sure about ->..

*      <line>-key = <value>->(field_name).

[kesavadas_thekkillath]

Can you try it this way. I have used the 7.4 syntax of declaration, please change it accordingly.

    LOOP AT object_table REFERENCE INTO object.
      APPEND INITIAL LINE TO <tab> REFERENCE INTO line.
      ASSIGN object->* TO <value>.
      ASSIGN line->* TO <line>.
      ASSIGN COMPONENT 'KEY' OF STRUCTURE <line> TO FIELD-SYMBOL(<fs_l>).
      ASSIGN COMPONENT 'OBJECT' OF STRUCTURE <line> TO FIELD-SYMBOL(<fs_o>).
      ASSIGN <value>->(field_name) TO FIELD-SYMBOL(<fs_v>).
      <fs_l> = <fs_v>.
      <fs_o> = object.
    ENDLOOP.

    DATA:sort_f1 TYPE fieldname.

    sort_f1 = 'KEY'.
    SORT <tab> BY (sort_f1).
    LOOP AT <tab> REFERENCE INTO line.
      APPEND INITIAL LINE TO object_table REFERENCE INTO object.
      ASSIGN line->* TO <line>.
      ASSIGN COMPONENT 'OBJECT' OF STRUCTURE <line> TO  <fs_o>.
      object = <fs_o>.
    ENDLOOP.

[Former Member]

Thanks Kesavadas, your construction ASSIGN COMPONENT was helpfull, but problem with assigning persists.

ASSIGN <value>->(field_name) TO <fs_v>.

I need something simillar to "ASSIGN COMPONENT" for object, because workbench said <value> is not reference variable.

[SuhaSaha]

Hello Michal,

Instead of TYPE ANY you should use the root object i.e., TYPE REF TO object.

BR,

Suhas

[Former Member]

Hi Suhas,
that's not possible because of erlier assignment

ASSIGN object->* TO <value>.

BR

[SuhaSaha]

I meant the root class (ABAP Keyword Documentation), my bad!

ASSIGN object->* TO <value>.

This is a classic case of ambiguous variable name I think you should consider not naming your variables as SAP keywords for the sake of the general masses

Cheersy cheers,

Suhas

[Former Member]

Ok guys, it's solved. It was little bit more complicated then I expected. Thanks for you help.

METHOD sort_object_table_by_field.

    TYPES: t_object TYPE REF TO object.

    DATA: obj_type_desc   TYPE REF TO cl_abap_refdescr,

          cls_type_desc   TYPE REF TO cl_abap_classdescr,

          tab_type_desc   TYPE REF TO cl_abap_tabledescr,

          elm_type_desc   TYPE REF TO cl_abap_elemdescr,

          struc_type_desc TYPE REF TO cl_abap_structdescr,

          r_line          TYPE REF TO data,

          r_tab           TYPE REF TO data,

          r_object        TYPE REF TO data,

          r_obj           TYPE REF TO data,

          lt_component TYPE cl_abap_structdescr=>component_table,

          ls_component LIKE LINE OF lt_component.

    FIELD-SYMBOLS: <object>    TYPE any,

                   <obj>       TYPE REF TO object,

                   <tab>       TYPE table,

                   <line>      TYPE any,

                   <key>       TYPE any,

                   <fs_key>    TYPE any,

                   <fs_object> TYPE any.

    READ TABLE object_table INDEX 1 ASSIGNING <object>.

    cls_type_desc ?= cl_abap_classdescr=>describe_by_object_ref( <object> ).

    elm_type_desc ?= cls_type_desc->get_attribute_type( field_name ).

    obj_type_desc ?= cl_abap_refdescr=>create( cls_type_desc ).

    UNASSIGN <object>.

    ls_component-name = 'key'.

    ls_component-type = elm_type_desc.

    APPEND ls_component TO lt_component.

    ls_component-name = 'object'.

    ls_component-type ?= obj_type_desc.

    APPEND ls_component TO lt_component.

    struc_type_desc ?= cl_abap_structdescr=>create( lt_component ).

    tab_type_desc ?= cl_abap_tabledescr=>create( p_line_type  = struc_type_desc

                                                 p_table_kind = cl_abap_tabledescr=>tablekind_std

                                                 p_unique     = abap_false ).

    REFRESH lt_component.

    CLEAR ls_component.

    CREATE DATA r_line TYPE HANDLE struc_type_desc.

    CREATE DATA r_tab TYPE HANDLE tab_type_desc.

    CREATE DATA r_object TYPE HANDLE obj_type_desc.

    CREATE DATA r_obj TYPE REF TO object.

    ASSIGN r_tab->* TO <tab>.

    LOOP AT object_table REFERENCE INTO r_object.

      APPEND INITIAL LINE TO <tab> REFERENCE INTO r_line.

      ASSIGN r_object->* TO <object>.

      ASSIGN r_obj->* TO <obj>.

      MOVE <object> TO <obj>.

      ASSIGN <obj>->(field_name) TO <key>.

      ASSIGN r_line->* TO <line>.

      ASSIGN COMPONENT 'KEY' OF STRUCTURE <line> TO <fs_key>.

      ASSIGN COMPONENT 'OBJECT' OF STRUCTURE <line> TO <fs_object>.

      <fs_object> = <object>.

      <fs_key> = <key>.

    ENDLOOP.

    DATA: sort_field TYPE fieldname.

    sort_field = 'KEY'.

    SORT <tab> BY (sort_field).

    REFRESH object_table.

    LOOP AT <tab> REFERENCE INTO r_line.

      APPEND INITIAL LINE TO object_table REFERENCE INTO r_object.

      ASSIGN r_line->* TO <line>.

      ASSIGN r_object->* TO <object>.

      ASSIGN COMPONENT 'OBJECT' OF STRUCTURE <line> TO <fs_object>.

      <object> = <fs_object>.

    ENDLOOP.

  ENDMETHOD.