ABAP OData Services: RESTful Web Services with SAP Gateway

METHOD /iwbep/if_mgw_appl_srv_runtime~get_entity.

  DATA: ls_key     TYPE /iwbep/s_mgw_name_value_pair,
        ls_order   TYPE zcl_zorders_mpc=>ts_order.

  " Read key from request
  READ TABLE it_key_tab INTO ls_key WITH KEY name = 'OrderId'.
  IF sy-subrc <> 0.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        textid = /iwbep/cx_mgw_busi_exception=>business_error
        message = 'OrderId is required'.
  ENDIF.

  " Read data from database
  SELECT SINGLE * FROM zorders INTO CORRESPONDING FIELDS OF ls_order
    WHERE order_id = ls_key-value.

  IF sy-subrc <> 0.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        textid = /iwbep/cx_mgw_busi_exception=>business_error_with_nav
        message = 'Order not found'.
  ENDIF.

  " Return result
  er_entity = ls_order.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~get_entityset.

  DATA: lt_orders  TYPE zcl_zorders_mpc=>tt_order,
        lt_filter  TYPE /iwbep/t_mgw_select_option,
        ls_paging  TYPE /iwbep/s_mgw_paging.

  " Read filter options
  lt_filter = io_tech_request_context->get_filter( )->get_filter_select_options( ).

  " Paging parameters
  ls_paging = io_tech_request_context->get_paging( ).

  " Create dynamic WHERE condition
  DATA(lo_filter) = io_tech_request_context->get_filter( ).
  DATA(lv_where) = lo_filter->get_filter_string( ).

  " Read data
  SELECT * FROM zorders
    WHERE (lv_where)
    ORDER BY order_id
    INTO CORRESPONDING FIELDS OF TABLE lt_orders
    UP TO ls_paging-top ROWS
    OFFSET ls_paging-skip.

  " Total count for $inlinecount
  IF io_tech_request_context->has_inlinecount( ) = abap_true.
    SELECT COUNT(*) FROM zorders WHERE (lv_where)
      INTO @DATA(lv_count).
    es_response_context-inlinecount = lv_count.
  ENDIF.

  et_entityset = lt_orders.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~create_entity.

  DATA: ls_order_in  TYPE zcl_zorders_mpc=>ts_order,
        ls_order_out TYPE zcl_zorders_mpc=>ts_order.

  " Read request body
  io_data_provider->read_entry_data( IMPORTING es_data = ls_order_in ).

  " Validation
  IF ls_order_in-customer_id IS INITIAL.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        message = 'Customer ID is required'.
  ENDIF.

  " Generate new ID
  SELECT MAX( order_id ) FROM zorders INTO @DATA(lv_max_id).
  ls_order_in-order_id = lv_max_id + 1.
  ls_order_in-created_at = sy-datum.
  ls_order_in-created_by = sy-uname.

  " Save data
  INSERT zorders FROM ls_order_in.

  IF sy-subrc = 0.
    ls_order_out = ls_order_in.
    er_entity = ls_order_out.
  ELSE.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        message = 'Error creating entity'.
  ENDIF.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~update_entity.

  DATA: ls_order TYPE zcl_zorders_mpc=>ts_order,
        ls_key   TYPE /iwbep/s_mgw_name_value_pair.

  " Read key and data
  READ TABLE it_key_tab INTO ls_key WITH KEY name = 'OrderId'.
  io_data_provider->read_entry_data( IMPORTING es_data = ls_order ).

  " Check order exists
  SELECT SINGLE * FROM zorders INTO @DATA(ls_existing)
    WHERE order_id = @ls_key-value.

  IF sy-subrc <> 0.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        message = 'Order not found'.
  ENDIF.

  " Perform update
  ls_order-order_id = ls_key-value.
  ls_order-changed_at = sy-datum.
  ls_order-changed_by = sy-uname.

  UPDATE zorders FROM ls_order.

  er_entity = ls_order.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~delete_entity.

  DATA: ls_key TYPE /iwbep/s_mgw_name_value_pair.

  READ TABLE it_key_tab INTO ls_key WITH KEY name = 'OrderId'.

  DELETE FROM zorders WHERE order_id = ls_key-value.

  IF sy-subrc <> 0.
    RAISE EXCEPTION TYPE /iwbep/cx_mgw_busi_exception
      EXPORTING
        message = 'Delete failed'.
  ENDIF.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~get_expanded_entityset.

  DATA: lt_orders TYPE zcl_zorders_mpc=>tt_order,
        lt_items  TYPE zcl_zorders_mpc=>tt_orderitem.

  " Load orders with $expand=Items
  SELECT * FROM zorders INTO CORRESPONDING FIELDS OF TABLE lt_orders.

  LOOP AT lt_orders ASSIGNING FIELD-SYMBOL(<ls_order>).
    " Load items for the order
    SELECT * FROM zorderitems
      WHERE order_id = <ls_order>-order_id
      INTO CORRESPONDING FIELDS OF TABLE lt_items.

    " Add expand data
    APPEND VALUE #(
      key  = <ls_order>-order_id
      data = lt_items
    ) TO et_expanded_tech_clauses.
  ENDLOOP.

  et_entityset = lt_orders.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~create_deep_entity.

  DATA: ls_order TYPE zcl_zorders_mpc=>ts_order_deep.

  " Read deep structure
  io_data_provider->read_entry_data( IMPORTING es_data = ls_order ).

  " Create order
  INSERT zorders FROM CORRESPONDING #( ls_order ).

  " Create items
  LOOP AT ls_order-items ASSIGNING FIELD-SYMBOL(<ls_item>).
    <ls_item>-order_id = ls_order-order_id.
    INSERT zorderitems FROM CORRESPONDING #( <ls_item> ).
  ENDLOOP.

  er_deep_entity = ls_order.

ENDMETHOD.

METHOD /iwbep/if_mgw_appl_srv_runtime~execute_action.

  CASE iv_action_name.
    WHEN 'ConfirmOrder'.
      " Read parameter
      DATA(lv_order_id) = VALUE #( it_parameter[ name = 'OrderId' ]-value OPTIONAL ).

      " Confirm order
      UPDATE zorders SET status = 'C' WHERE order_id = lv_order_id.

      IF sy-subrc = 0.
        er_data = VALUE zcl_zorders_mpc=>ts_result( success = abap_true ).
      ENDIF.

    WHEN 'GetOrderStatistics'.
      SELECT COUNT(*) AS total,
             SUM( CASE WHEN status = 'O' THEN 1 ELSE 0 END ) AS open,
             SUM( CASE WHEN status = 'C' THEN 1 ELSE 0 END ) AS closed
        FROM zorders INTO @DATA(ls_stats).

      er_data = ls_stats.
  ENDCASE.

ENDMETHOD.

@AbapCatalog.viewEnhancementCategory: [#NONE]
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Orders'
@Metadata.allowExtensions: true
define root view entity ZI_Order
  as select from zorders
  composition [0..*] of ZI_OrderItem as _Items
{
  key order_id      as OrderId,
      customer_id   as CustomerId,
      order_date    as OrderDate,
      status        as Status,
      total_amount  as TotalAmount,
      currency      as Currency,

      @Semantics.user.createdBy: true
      created_by    as CreatedBy,
      @Semantics.systemDateTime.createdAt: true
      created_at    as CreatedAt,

      _Items
}

@EndUserText.label: 'Orders Projection'
@AccessControl.authorizationCheck: #CHECK
@Metadata.allowExtensions: true
define root view entity ZC_Order
  provider contract transactional_query
  as projection on ZI_Order
{
  key OrderId,
      CustomerId,
      OrderDate,
      Status,
      @Semantics.amount.currencyCode: 'Currency'
      TotalAmount,
      Currency,

      _Items : redirected to composition child ZC_OrderItem
}

@EndUserText.label: 'Order Service'
define service ZSB_Order {
  expose ZC_Order as Orders;
  expose ZC_OrderItem as OrderItems;
}

managed implementation in class zbp_i_order unique;
strict ( 2 );

define behavior for ZI_Order alias Order
persistent table zorders
lock master
authorization master ( instance )
{
  field ( readonly ) OrderId, CreatedBy, CreatedAt;
  field ( mandatory ) CustomerId;

  create;
  update;
  delete;

  action confirmOrder result [1] $self;

  determination setDefaults on modify { create; }
  validation validateCustomer on save { field CustomerId; }

  association _Items { create; }
}

CLASS lhc_order DEFINITION INHERITING FROM cl_abap_behavior_handler.
  PRIVATE SECTION.
    METHODS:
      get_instance_authorizations FOR INSTANCE AUTHORIZATION
        IMPORTING keys REQUEST requested_authorizations
        RESULT result,

      confirmOrder FOR MODIFY
        IMPORTING keys FOR ACTION order~confirmOrder
        RESULT result,

      setDefaults FOR DETERMINE ON MODIFY
        IMPORTING keys FOR order~setDefaults,

      validateCustomer FOR VALIDATE ON SAVE
        IMPORTING keys FOR order~validateCustomer.
ENDCLASS.

CLASS lhc_order IMPLEMENTATION.

  METHOD get_instance_authorizations.
    " Authorization check
    LOOP AT keys ASSIGNING FIELD-SYMBOL(<key>).
      APPEND VALUE #(
        %tky = <key>-%tky
        %op-%update = COND #(
          WHEN has_authority( ) = abap_true
          THEN if_abap_behv=>auth-allowed
          ELSE if_abap_behv=>auth-unauthorized )
      ) TO result.
    ENDLOOP.
  ENDMETHOD.

  METHOD confirmOrder.
    " Read orders
    READ ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        FIELDS ( Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_orders).

    " Update status
    MODIFY ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        UPDATE FIELDS ( Status )
        WITH VALUE #( FOR order IN lt_orders
          ( %tky = order-%tky
            Status = 'C' ) ).

    " Return result
    READ ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        ALL FIELDS
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_result).

    result = VALUE #( FOR order IN lt_result
      ( %tky = order-%tky
        %param = order ) ).
  ENDMETHOD.

  METHOD setDefaults.
    READ ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        FIELDS ( OrderDate Status )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_orders).

    MODIFY ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        UPDATE FIELDS ( OrderDate Status )
        WITH VALUE #( FOR order IN lt_orders
          WHERE ( OrderDate IS INITIAL )
          ( %tky = order-%tky
            OrderDate = cl_abap_context_info=>get_system_date( )
            Status = 'O' ) ).
  ENDMETHOD.

  METHOD validateCustomer.
    READ ENTITIES OF zi_order IN LOCAL MODE
      ENTITY order
        FIELDS ( CustomerId )
        WITH CORRESPONDING #( keys )
      RESULT DATA(lt_orders).

    LOOP AT lt_orders INTO DATA(ls_order).
      " Check customer exists
      SELECT SINGLE @abap_true FROM zcustomers
        WHERE customer_id = @ls_order-CustomerId
        INTO @DATA(lv_exists).

      IF lv_exists = abap_false.
        APPEND VALUE #(
          %tky = ls_order-%tky
          %msg = new_message_with_text(
            severity = if_abap_behv_message=>severity-error
            text = 'Customer does not exist' )
        ) TO failed-order.
      ENDIF.
    ENDLOOP.
  ENDMETHOD.

ENDCLASS.

CLASS zcl_order_query DEFINITION
  PUBLIC FINAL
  CREATE PUBLIC.

  PUBLIC SECTION.
    INTERFACES if_rap_query_provider.
ENDCLASS.

CLASS zcl_order_query IMPLEMENTATION.

  METHOD if_rap_query_provider~select.

    DATA: lt_orders TYPE TABLE OF zi_order.

    " Read filter
    DATA(lt_filter) = io_request->get_filter( )->get_as_ranges( ).

    " Paging
    DATA(lv_top)  = io_request->get_paging( )->get_page_size( ).
    DATA(lv_skip) = io_request->get_paging( )->get_offset( ).

    " Sorting
    DATA(lt_sort) = io_request->get_sort_elements( ).

    " Read data with dynamic filter
    SELECT * FROM zi_order
      WHERE customer_id IN @( VALUE #( FOR filter IN lt_filter
        WHERE ( name = 'CUSTOMERID' )
        ( filter-range ) ) )
      ORDER BY order_id
      INTO TABLE @lt_orders
      UP TO @lv_top ROWS
      OFFSET @lv_skip.

    " Total count
    IF io_request->is_total_numb_of_rec_requested( ).
      SELECT COUNT(*) FROM zi_order INTO @DATA(lv_count).
      io_response->set_total_number_of_records( lv_count ).
    ENDIF.

    io_response->set_data( lt_orders ).

  ENDMETHOD.

ENDCLASS.