Paging with oData on Entityset Itab – Example implementation

Hello,

i would like to share some code, that can be used to handle the paging (top, skip) parameters on an entityset internal table. I use this often if the entityset is not that big or if i cant handle top skip with select statements.

I hope this can be an example to start from if you have to impelemnt top skip parameters from gateway.

The method has the following parameters:

is_paging type /IWBEP/S_MGW_PAGING. (IMPORTING)

ct_entityset type table (CHANGING)

method DO_PAGING.

* Handle Top/Skip

     DATA: lv_top        TYPE int4,

           lv_skip       TYPE int4,

           lv_table_size TYPE i,

           lo_tabdesc    TYPE REF TO cl_abap_tabledescr,

           lo_strucdesc  TYPE REF TO cl_abap_datadescr,

           rs_data       TYPE REF TO data,

           rt_data       TYPE REF TO data.

     FIELD-SYMBOLS: <fs_data> TYPE any,

                    <ft_data> TYPE ANY TABLE.

* Top/Skip assign local

     lv_top = is_paging–top.

     lv_skip = is_paging–skip.

     lo_tabdesc ?= cl_abap_tabledescr=>describe_by_data( p_data = ct_entityset ).

     lo_strucdesc = lo_tabdesc->get_table_line_type( ).

     CREATE DATA rs_data TYPE (lo_strucdesc->absolute_name).

     CREATE DATA rt_data TYPE STANDARD TABLE OF (lo_strucdesc->absolute_name).

     ASSIGN rs_data->* TO <fs_data>.

     ASSIGN rt_data->* TO <ft_data>.

     <ft_data> = ct_entityset.

     REFRESH ct_entityset.

     “Client Paging (top/skip)

     IF lv_top IS NOT INITIAL OR

        lv_skip IS NOT INITIAL.

       LOOP AT <ft_data> ASSIGNING <fs_data>.

         IF sy–tabix > lv_skip.

           APPEND <fs_data> TO ct_entityset.

           DESCRIBE TABLE ct_entityset LINES lv_table_size.

           IF lv_top IS NOT INITIAL AND

              lv_table_size >= lv_top.

             EXIT.

           ENDIF.

         ENDIF.

       ENDLOOP.

       “No Paging

     ELSE.

       ct_entityset = <ft_data>.

     ENDIF.

   endmethod.

By now after completing several implementations using the netweaver gateway i really enjoy to work with the netweaver gateway. We realised several services that are used by sap and non-sap frontends and i personally think, that the netweaver is a great product of sap & will be really important for future development tasks. Especially i think the product is really stable as i did not have a single critical issue during productive use of the gateway. Only once we forgot to update the metadata of the service in production – but this was a 2 minute thing to solve. @Gateway Developers: Keep up the good work! Can’t wait to see new features comming up.

Thanks for your feedback & rating the document if it was helpful to you.

I wish you a nice day.

Kind regards,

Michael