RAP Abstract Entities: Flexible Custom Queries ohne Datenbank

@EndUserText.label: 'Externe Wetterdaten'
define abstract entity ZA_WeatherData
{
  City        : abap.char(40);
  Temperature : abap.dec(5,2);
  Humidity    : abap.int2;
  Conditions  : abap.char(50);
  Timestamp   : abap.utclong;
}

@EndUserText.label: 'Buchungsparameter'
define abstract entity ZA_BookingParameters
{
  BookingDate   : abap.dats;
  CustomerID    : abap.numc(10);
  ProductID     : abap.char(18);
  Quantity      : abap.int4;
  DiscountCode  : abap.char(10);
  PaymentMethod : abap.char(20);
}

action createBooking parameter ZA_BookingParameters result [1] $self;

@EndUserText.label: 'Preisberechnung Ergebnis'
define abstract entity ZA_PriceCalculationResult
{
  NetPrice        : abap.dec(15,2);
  TaxAmount       : abap.dec(15,2);
  GrossPrice      : abap.dec(15,2);
  Currency        : abap.cuky;
  DiscountApplied : abap_boolean;
  DiscountPercent : abap.dec(5,2);
  ValidUntil      : abap.dats;
}

@EndUserText.label: 'Waehrungskurse'
@ObjectModel.query.implementedBy: 'ABAP:ZCL_EXCHANGE_RATE_QUERY'
define custom entity ZI_ExchangeRate
{
  key SourceCurrency : abap.cuky;
  key TargetCurrency : abap.cuky;
      ExchangeRate   : abap.dec(15,5);
      RateDate       : abap.dats;
      Provider       : abap.char(20);
}

CLASS zcl_exchange_rate_query DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_rap_query_provider.

  PRIVATE SECTION.
    METHODS fetch_rates_from_api
      RETURNING VALUE(rt_rates) TYPE zt_exchange_rates.
ENDCLASS.

CLASS zcl_exchange_rate_query IMPLEMENTATION.
  METHOD if_rap_query_provider~select.
    " 1. Pruefen ob Daten angefordert werden
    IF io_request->is_data_requested( ) = abap_false.
      RETURN.
    ENDIF.

    " 2. Filter abrufen
    DATA(lt_filter) = io_request->get_filter( )->get_as_ranges( ).

    " 3. Paging abrufen
    DATA(lv_offset) = io_request->get_paging( )->get_offset( ).
    DATA(lv_page_size) = io_request->get_paging( )->get_page_size( ).

    " 4. Daten von externer API abrufen
    DATA(lt_rates) = fetch_rates_from_api( ).

    " 5. Filter anwenden
    DATA lt_result TYPE STANDARD TABLE OF zi_exchangerate.
    LOOP AT lt_rates INTO DATA(ls_rate).
      " Filterkriterien pruefen
      IF lt_filter IS NOT INITIAL.
        DATA(lv_match) = abap_true.
        LOOP AT lt_filter INTO DATA(ls_filter).
          CASE ls_filter-name.
            WHEN 'SOURCECURRENCY'.
              IF NOT ls_rate-source_currency IN ls_filter-range.
                lv_match = abap_false.
              ENDIF.
            WHEN 'TARGETCURRENCY'.
              IF NOT ls_rate-target_currency IN ls_filter-range.
                lv_match = abap_false.
              ENDIF.
          ENDCASE.
        ENDLOOP.
        IF lv_match = abap_false.
          CONTINUE.
        ENDIF.
      ENDIF.

      APPEND VALUE #(
        SourceCurrency = ls_rate-source_currency
        TargetCurrency = ls_rate-target_currency
        ExchangeRate   = ls_rate-rate
        RateDate       = ls_rate-rate_date
        Provider       = ls_rate-provider
      ) TO lt_result.
    ENDLOOP.

    " 6. Gesamtanzahl fuer Paging
    IF io_request->is_total_numb_of_rec_requested( ).
      io_response->set_total_number_of_records( lines( lt_result ) ).
    ENDIF.

    " 7. Paging anwenden
    IF lv_page_size > 0.
      DATA(lv_to) = lv_offset + lv_page_size.
      IF lv_to > lines( lt_result ).
        lv_to = lines( lt_result ).
      ENDIF.
      lt_result = VALUE #( FOR i = lv_offset + 1 WHILE i <= lv_to
                           ( lt_result[ i ] ) ).
    ENDIF.

    " 8. Daten zurueckgeben
    io_response->set_data( lt_result ).
  ENDMETHOD.

  METHOD fetch_rates_from_api.
    " HTTP-Client erstellen
    TRY.
        DATA(lo_destination) = cl_http_destination_provider=>create_by_comm_arrangement(
          comm_scenario  = 'Z_EXCHANGE_RATE_API'
          service_id     = 'Z_EXCHANGE_RATE_OUTBOUND'
        ).

        DATA(lo_client) = cl_web_http_client_manager=>create_by_http_destination( lo_destination ).
        DATA(lo_request) = lo_client->get_http_request( ).
        lo_request->set_uri_path( '/api/v1/rates' ).

        DATA(lo_response) = lo_client->execute( if_web_http_client=>get ).
        DATA(lv_json) = lo_response->get_text( ).

        " JSON parsen
        /ui2/cl_json=>deserialize(
          EXPORTING
            json = lv_json
          CHANGING
            data = rt_rates
        ).

      CATCH cx_root INTO DATA(lx_error).
        " Fehler loggen, leere Tabelle zurueckgeben
        " Oder: RAISE SHORTDUMP
    ENDTRY.
  ENDMETHOD.
ENDCLASS.

METHOD fetch_weather_data.
  TRY.
      DATA(lo_dest) = cl_http_destination_provider=>create_by_comm_arrangement(
        comm_scenario = 'Z_WEATHER_API'
      ).

      DATA(lo_client) = cl_web_http_client_manager=>create_by_http_destination( lo_dest ).
      DATA(lo_request) = lo_client->get_http_request( ).

      " Query-Parameter setzen
      lo_request->set_uri_path( |/weather?city={ iv_city }&units=metric| ).
      lo_request->set_header_field(
        i_name  = 'Accept'
        i_value = 'application/json'
      ).

      DATA(lo_response) = lo_client->execute( if_web_http_client=>get ).

      IF lo_response->get_status( )-code = 200.
        DATA(lv_json) = lo_response->get_text( ).
        parse_weather_json( EXPORTING iv_json = lv_json
                            IMPORTING es_weather = rs_weather ).
      ENDIF.

    CATCH cx_http_dest_provider_error
          cx_web_http_client_error INTO DATA(lx_error).
      " Fehlerbehandlung
  ENDTRY.
ENDMETHOD.

METHOD fetch_from_legacy_system.
  DATA: lv_message TYPE c LENGTH 200.

  TRY.
      DATA(lo_dest) = cl_rfc_destination_provider=>create_by_cloud_destination(
        i_name = 'SAP_ECC_SYSTEM'
      ).

      CALL FUNCTION 'Z_GET_PRODUCT_STOCK'
        DESTINATION lo_dest->get_destination_name( )
        EXPORTING
          iv_material = iv_material
        IMPORTING
          ev_stock    = rv_stock
        EXCEPTIONS
          communication_failure = 1 MESSAGE lv_message
          system_failure        = 2 MESSAGE lv_message
          OTHERS                = 3.

      IF sy-subrc <> 0.
        " Fehler loggen
      ENDIF.

    CATCH cx_rfc_dest_provider_error INTO DATA(lx_error).
      " Destination nicht gefunden
  ENDTRY.
ENDMETHOD.

@EndUserText.label: 'Dashboard KPIs'
@ObjectModel.query.implementedBy: 'ABAP:ZCL_DASHBOARD_QUERY'
define custom entity ZI_DashboardKPI
{
  key KPIId           : abap.char(20);
      KPIName         : abap.char(60);
      KPIValue        : abap.dec(15,2);
      KPIUnit         : abap.char(10);
      Trend           : abap.int1;  // -1, 0, 1
      TrendPercent    : abap.dec(5,2);
      ComparisonValue : abap.dec(15,2);
      Status          : abap.char(10);  // Good, Warning, Critical
      Category        : abap.char(30);
      LastUpdated     : abap.utclong;
}

CLASS zcl_dashboard_query DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_rap_query_provider.

  PRIVATE SECTION.
    METHODS get_sales_kpis RETURNING VALUE(rt_kpis) TYPE zt_dashboard_kpis.
    METHODS get_inventory_kpis RETURNING VALUE(rt_kpis) TYPE zt_dashboard_kpis.
    METHODS get_customer_kpis RETURNING VALUE(rt_kpis) TYPE zt_dashboard_kpis.
    METHODS calculate_trend
      IMPORTING iv_current TYPE decfloat34
                iv_previous TYPE decfloat34
      EXPORTING ev_trend TYPE i
                ev_percent TYPE decfloat34.
ENDCLASS.

CLASS zcl_dashboard_query IMPLEMENTATION.
  METHOD if_rap_query_provider~select.
    IF io_request->is_data_requested( ) = abap_false.
      RETURN.
    ENDIF.

    " Daten aus verschiedenen Quellen aggregieren
    DATA lt_kpis TYPE STANDARD TABLE OF zi_dashboardkpi.

    " Sales KPIs aus CDS View
    APPEND LINES OF get_sales_kpis( ) TO lt_kpis.

    " Inventory KPIs aus Legacy-System via RFC
    APPEND LINES OF get_inventory_kpis( ) TO lt_kpis.

    " Customer KPIs aus externer API
    APPEND LINES OF get_customer_kpis( ) TO lt_kpis.

    " Filter anwenden
    DATA(lt_filter) = io_request->get_filter( )->get_as_ranges( ).
    IF lt_filter IS NOT INITIAL.
      LOOP AT lt_kpis ASSIGNING FIELD-SYMBOL(<ls_kpi>).
        LOOP AT lt_filter INTO DATA(ls_filter).
          CASE ls_filter-name.
            WHEN 'CATEGORY'.
              IF NOT <ls_kpi>-Category IN ls_filter-range.
                DELETE lt_kpis.
              ENDIF.
          ENDCASE.
        ENDLOOP.
      ENDLOOP.
    ENDIF.

    IF io_request->is_total_numb_of_rec_requested( ).
      io_response->set_total_number_of_records( lines( lt_kpis ) ).
    ENDIF.

    io_response->set_data( lt_kpis ).
  ENDMETHOD.

  METHOD get_sales_kpis.
    " Aktuelle und vorherige Periode aus CDS View
    SELECT SUM( net_amount ) AS current_sales
      FROM zi_salesorder
      WHERE created_at >= @( cl_abap_context_info=>get_system_date( ) - 30 )
      INTO @DATA(lv_current_sales).

    SELECT SUM( net_amount ) AS previous_sales
      FROM zi_salesorder
      WHERE created_at >= @( cl_abap_context_info=>get_system_date( ) - 60 )
        AND created_at < @( cl_abap_context_info=>get_system_date( ) - 30 )
      INTO @DATA(lv_previous_sales).

    DATA: lv_trend TYPE i,
          lv_percent TYPE decfloat34.

    calculate_trend(
      EXPORTING iv_current = lv_current_sales
                iv_previous = lv_previous_sales
      IMPORTING ev_trend = lv_trend
                ev_percent = lv_percent ).

    APPEND VALUE #(
      KPIId           = 'SALES_30D'
      KPIName         = 'Umsatz (30 Tage)'
      KPIValue        = lv_current_sales
      KPIUnit         = 'EUR'
      Trend           = lv_trend
      TrendPercent    = lv_percent
      ComparisonValue = lv_previous_sales
      Status          = COND #( WHEN lv_trend >= 0 THEN 'Good'
                                WHEN lv_percent > -10 THEN 'Warning'
                                ELSE 'Critical' )
      Category        = 'Sales'
      LastUpdated     = utclong_current( )
    ) TO rt_kpis.
  ENDMETHOD.

  METHOD calculate_trend.
    IF iv_previous = 0.
      ev_trend = 0.
      ev_percent = 0.
    ELSE.
      ev_percent = ( iv_current - iv_previous ) / iv_previous * 100.
      ev_trend = COND #( WHEN ev_percent > 0 THEN 1
                         WHEN ev_percent < 0 THEN -1
                         ELSE 0 ).
    ENDIF.
  ENDMETHOD.

  " Weitere Methoden...
ENDCLASS.

CLASS zcl_cached_query DEFINITION
  PUBLIC
  FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_rap_query_provider.

  PRIVATE SECTION.
    CLASS-DATA: gt_cache TYPE zt_cached_data,
                gv_cache_timestamp TYPE utclong.

    CLASS-METHODS is_cache_valid RETURNING VALUE(rv_valid) TYPE abap_bool.
    METHODS refresh_cache.

    CONSTANTS: gc_cache_duration_seconds TYPE i VALUE 300. " 5 Minuten
ENDCLASS.

CLASS zcl_cached_query IMPLEMENTATION.
  METHOD is_cache_valid.
    IF gv_cache_timestamp IS INITIAL.
      rv_valid = abap_false.
      RETURN.
    ENDIF.

    DATA(lv_age) = utclong_diff(
      high = utclong_current( )
      low  = gv_cache_timestamp
    ).

    rv_valid = xsdbool( lv_age < gc_cache_duration_seconds ).
  ENDMETHOD.

  METHOD if_rap_query_provider~select.
    IF io_request->is_data_requested( ) = abap_false.
      RETURN.
    ENDIF.

    " Cache pruefen
    IF is_cache_valid( ) = abap_false.
      refresh_cache( ).
    ENDIF.

    " Daten aus Cache zurueckgeben
    io_response->set_data( gt_cache ).
  ENDMETHOD.

  METHOD refresh_cache.
    " Externe Daten abrufen
    gt_cache = fetch_external_data( ).
    gv_cache_timestamp = utclong_current( ).
  ENDMETHOD.
ENDCLASS.

METHOD fetch_data_parallel.
  " Mehrere Datenquellen parallel abrufen
  DATA: lt_tasks TYPE TABLE OF REF TO zcl_data_fetch_task.

  " Tasks erstellen
  APPEND NEW zcl_data_fetch_task( 'SOURCE_A' ) TO lt_tasks.
  APPEND NEW zcl_data_fetch_task( 'SOURCE_B' ) TO lt_tasks.
  APPEND NEW zcl_data_fetch_task( 'SOURCE_C' ) TO lt_tasks.

  " Parallel ausfuehren
  DATA(lo_parallel) = NEW cl_abap_parallel( ).
  lo_parallel->run_instances(
    EXPORTING
      p_in_tab  = lt_tasks
    IMPORTING
      p_out_tab = DATA(lt_results)
  ).

  " Ergebnisse aggregieren
  LOOP AT lt_results INTO DATA(lo_result).
    APPEND LINES OF lo_result->get_data( ) TO rt_combined_data.
  ENDLOOP.
ENDMETHOD.

METHOD if_rap_query_provider~select.
  TRY.
      " Daten abrufen
      DATA(lt_data) = fetch_external_data( ).
      io_response->set_data( lt_data ).

    CATCH cx_http_dest_provider_error
          cx_web_http_client_error INTO DATA(lx_http_error).
      " HTTP-Fehler: Leere Antwort oder Fallback-Daten
      io_response->set_data( VALUE #( ) ).

      " Optional: Business Exception ausloesen
      RAISE EXCEPTION TYPE zcx_external_service_error
        EXPORTING
          textid = zcx_external_service_error=>service_unavailable
          service_name = 'Weather API'.

    CATCH cx_root INTO DATA(lx_error).
      " Generischer Fehler loggen
      cl_bali_log=>create_with_header(
        EXPORTING
          header = cl_bali_header_setter=>create(
            object      = 'ZDASHBOARD'
            subobject   = 'QUERY'
          )
      )->add_item(
        item = cl_bali_exception_setter=>create(
          exception = lx_error
        )
      )->save( ).

      io_response->set_data( VALUE #( ) ).
  ENDTRY.
ENDMETHOD.