• Secure HTTP communication via BTP destinations
• CSRF token handling
• JSON serialization/deserialization
• Clean separation between connection setup and data retrieval

Code:

CLASS /iap/cl_intelligent_matching DEFINITION
PUBLIC FINAL
CREATE PUBLIC.

PUBLIC SECTION.

“———————————————————————-
” Structure for API Response (Raw Material Compliance Info)
“———————————————————————-
TYPES: BEGIN OF ty_rawmat_result,
uuid TYPE string, ” Unique ID of the record
material_id TYPE string, ” Material number
material_name TYPE string, ” Material description
material_group TYPE string, ” Material group code
material_group_name TYPE string, ” Material group name
is_active TYPE abap_bool, ” Active status flag
END OF ty_rawmat_result.

“———————————————————————-
” Public Methods
“———————————————————————-
CLASS-METHODS:
create_client_proxy
RETURNING VALUE(ro_client_proxy) TYPE REF TO /iwbep/if_cp_client_proxy,

get_rawmat_data
RETURNING VALUE(rt_rawmat_data) TYPE STANDARD TABLE OF ty_rawmat_result,

convert_to_json
IMPORTING it_data TYPE any
EXPORTING ev_json TYPE string.

PRIVATE SECTION.
CONSTANTS:
c_destination TYPE string VALUE ‘DEMO_EHS_DEST’. ” Destination configured in BTP Cockpit

ENDCLASS.

CLASS /iap/cl_intelligent_matching IMPLEMENTATION.

“———————————————————————-
” 1. Create OData V4 Client Proxy
“———————————————————————-
METHOD create_client_proxy.

TRY.
” Create destination object from BTP destination service
DATA(lo_destination) = cl_http_destination_provider=>create_by_cloud_destination(
i_name = c_destination
i_authn_mode = if_a4c_cp_service=>service_specific ).

” Create HTTP client for communication
DATA(lo_http_client) = cl_web_http_client_manager=>create_by_http_destination( lo_destination ).

” Create remote OData V4 proxy for the target service
ro_client_proxy = /iwbep/cl_cp_factory_remote=>create_v4_remote_proxy(
is_proxy_model_key = VALUE #(
repository_id = ‘DEFAULT’
proxy_model_id = ‘/IAP/CHM_SCM_IM’
proxy_model_version = ‘0001’ )
io_http_client = lo_http_client
iv_relative_service_root = ‘/sap/opu/odata/sap/ZDEMO_EHS_SRV/’ ). ” Demo endpoint

CATCH cx_http_dest_provider_error INTO DATA(lx_dest_err).
MESSAGE lx_dest_err->get_text( ) TYPE ‘E’.
CATCH cx_root INTO DATA(lx_root).
MESSAGE lx_root->get_text( ) TYPE ‘E’.
ENDTRY.

ENDMETHOD.

“———————————————————————-
” 2. Fetch Raw Material Data from External API
“———————————————————————-
METHOD get_rawmat_data.

DATA: lo_destination TYPE REF TO if_http_destination,
lo_http_client TYPE REF TO if_web_http_client,
lo_response TYPE REF TO if_web_http_response,
lv_json TYPE string,
lv_http_status TYPE i.

TRY.
” Obtain HTTP destination (configured in BTP cockpit)
lo_destination = cl_http_destination_provider=>create_by_cloud_destination(
i_name = c_destination
i_authn_mode = if_a4c_cp_service=>service_specific ).

lo_http_client = cl_web_http_client_manager=>create_by_http_destination( lo_destination ).

” === Step 1: Fetch CSRF Token ===
DATA(lo_req_token) = lo_http_client->get_http_request( ).
lo_req_token->set_header_field( name = ‘X-CSRF-Token’ value = ‘Fetch’ ).

DATA(lo_resp_token) = lo_http_client->execute( if_web_http_client=>get ).
DATA(lv_csrf_token) = lo_resp_token->get_header_field( ‘X-CSRF-Token’ ).

” === Step 2: Perform GET Request to Demo API ===
DATA(lo_req_get) = lo_http_client->get_http_request( ).
lo_req_get->set_header_field( name = ‘X-CSRF-Token’ value = lv_csrf_token ).
lo_req_get->set_header_field( name = ‘Accept’ value = ‘application/json’ ).

lo_response = lo_http_client->execute(
i_method = if_web_http_client=>get
i_relative_url = ‘/sap/opu/odata/sap/ZDEMO_EHS_SRV/C_RawMatInfoSet’ ). ” Demo path

lv_http_status = lo_response->get_status( ).

IF lv_http_status = 200.
lv_json = lo_response->get_text( ).

/ui2/cl_json=>deserialize(
EXPORTING json = lv_json
CHANGING data = rt_rawmat_data ).

ELSE.
MESSAGE |HTTP Error { lv_http_status }: { lo_response->get_status_text( ) }| TYPE ‘E’.
ENDIF.

CATCH cx_http_dest_provider_error INTO DATA(lx_dest_error).
MESSAGE lx_dest_error->get_text( ) TYPE ‘E’.

CATCH cx_web_http_client_error INTO DATA(lx_http_error).
MESSAGE lx_http_error->get_text( ) TYPE ‘E’.

CATCH cx_root INTO DATA(lx_any).
MESSAGE lx_any->get_text( ) TYPE ‘E’.
ENDTRY.

ENDMETHOD.

“———————————————————————-
” 3. Convert Any ABAP Data Structure to JSON String
“———————————————————————-
METHOD convert_to_json.
ev_json = /ui2/cl_json=>serialize(
EXPORTING
data = it_data
conversion_exits = abap_true
pretty_name = /ui2/cl_json=>pretty_mode-camel_case ).
ENDMETHOD.

ENDCLASS.

HIDE → to store values “hidden” behind a line for later retrieval.

USER COMMAND (AT USER-COMMAND) → to react to user actions (e.g., double-clicks, buttons, PF keys).

1. GET CURSOR

This is used to know where the user placed the cursor or clicked in a list.

GET CURSOR FIELD gv_field VALUE gv_value.

• gv_field → variable to hold the field name under the cursor.
• gv_value → variable to hold the value of that field.

Example:

GET CURSOR FIELD lv_field VALUE lv_value.
WRITE: / ‘Cursor on:’, lv_field, ‘Value:’, lv_value.

2. HIDE

The HIDE statement stores the value of a variable in the system’s hide area, linked to the current line.
Later, when the user double-clicks on that line, the hidden values are retrieved automatically.

Example:

LOOP AT it_mara INTO wa_mara.
WRITE: / wa_mara-matnr, wa_mara-maktx.
HIDE: wa_mara-matnr, wa_mara-maktx.
ENDLOOP.

When the user double-clicks on a line, the hidden fields for that line become available again.

3. USER COMMAND (AT USER-COMMAND)

This event block reacts to user actions (function keys, buttons, or double-clicks).

Example:

AT USER-COMMAND.
CASE sy-ucomm.
WHEN ‘DETAIL’. “Custom function code
WRITE: / ‘Details for material:’, wa_mara-matnr.
WHEN ‘EXIT’.
LEAVE PROGRAM.
ENDCASE.

Full Example:

REPORT zsample_report.

TABLES: mara.

DATA: wa_mara TYPE mara.

START-OF-SELECTION.
SELECT * FROM mara UP TO 10 ROWS.
WRITE: / mara-matnr, mara-mtart, mara-mbrsh.
HIDE: mara-matnr.
ENDSELECT.

AT LINE-SELECTION. “Triggered by double-click
WRITE: / ‘You selected material:’, mara-matnr.

AT USER-COMMAND.
CASE sy-ucomm.
WHEN ‘DETAIL’.
GET CURSOR FIELD DATA(lv_field) VALUE DATA(lv_value).
WRITE: / ‘Field:’, lv_field, ‘Value:’, lv_value.
WHEN ‘EXIT’.
LEAVE PROGRAM.
ENDCASE.

In the SAP function module world, this is usually done using:
👉 REUSE_ALV_HIERSEQ_LIST_DISPLAY

*&———————————————————————*
*& Report  ZTEST_PROGRAM_2
*&
*&———————————————————————*
*&
*&
*&———————————————————————*

REPORT ztest_program_2.

TYPE-POOLS: slis.

DATA: it_mara TYPE TABLE OF mara,
it_marc TYPE TABLE OF marc.

DATA: it_fieldcat_header TYPE slis_t_fieldcat_alv,
it_fieldcat_item   TYPE slis_t_fieldcat_alv,
wa_fieldcat        TYPE slis_fieldcat_alv.

DATA: gs_keyinfo TYPE slis_keyinfo_alv.

“— Fetch Data (limit for demo)
SELECT * FROM mara UP TO 10 ROWS INTO TABLE it_mara.
SELECT * FROM marc UP TO 50 ROWS INTO TABLE it_marc.

“— Build Field Catalog for MARA (Header)
CLEAR wa_fieldcat.
wa_fieldcat–fieldname = ‘MATNR’.
wa_fieldcat–seltext_m = ‘Material’.
APPEND wa_fieldcat TO it_fieldcat_header.

CLEAR wa_fieldcat.
wa_fieldcat–fieldname = ‘MTART’.
wa_fieldcat–seltext_m = ‘Material Type’.
APPEND wa_fieldcat TO it_fieldcat_header.

“— Build Field Catalog for MARC (Item)
CLEAR wa_fieldcat.
wa_fieldcat–fieldname = ‘MATNR’.
wa_fieldcat–seltext_m = ‘Material’.
APPEND wa_fieldcat TO it_fieldcat_item.

CLEAR wa_fieldcat.
wa_fieldcat–fieldname = ‘WERKS’.
wa_fieldcat–seltext_m = ‘Plant’.
APPEND wa_fieldcat TO it_fieldcat_item.

CLEAR wa_fieldcat.
wa_fieldcat–fieldname = ‘DISMM’.
wa_fieldcat–seltext_m = ‘MRP Type’.
APPEND wa_fieldcat TO it_fieldcat_item.

“— Key Information (join condition between header and item)
gs_keyinfo–header01 = ‘MATNR’. ” Header Key
gs_keyinfo–item01   = ‘MATNR’. ” Item Key

“— Display Hierarchical ALV
CALL FUNCTION ‘REUSE_ALV_HIERSEQ_LIST_DISPLAY’
EXPORTING
i_callback_program      = sy–repid
is_keyinfo              = gs_keyinfo
i_structure_name_header = ‘MARA’
i_structure_name_item   = ‘MARC’
i_tabname_header        = ‘MARA’
i_tabname_item          = ‘MARC’
TABLES
t_outtab_header         = it_mara
t_outtab_item           = it_marc
EXCEPTIONS
program_error           = 1
OTHERS                  = 2.

IF sy–subrc <> 0.
MESSAGE ID sy–msgid TYPE sy–msgty NUMBER sy–msgno
WITH sy–msgv1 sy–msgv2 sy–msgv3 sy–msgv4.
ENDIF.

Output:

Steps to Create ALV Block List

1. Initialize block list → REUSE_ALV_BLOCK_LIST_INIT.

2. Add multiple reports (MARA, MARC, etc.) → REUSE_ALV_BLOCK_LIST_APPEND.

3. Display → REUSE_ALV_BLOCK_LIST_DISPLAY.

*&---------------------------------------------------------------------*
*& Report  ZTEST_PROGRAM_2
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT ztest_program_2.

TYPE-POOLS: slis.

DATA: it_mara TYPE TABLE OF mara,
      it_marc TYPE TABLE OF marc.

DATA: it_fieldcat TYPE slis_t_fieldcat_alv,
      wa_fieldcat TYPE slis_fieldcat_alv.

DATA : lt_events TYPE slis_t_event.


"--- Main processing

START-OF-SELECTION.

  "--- Fetch Data
  SELECT * FROM mara UP TO 20 ROWS INTO TABLE it_mara.
  SELECT * FROM marc UP TO 20 ROWS INTO TABLE it_marc.

  "Initialize ALV Block List
  CALL FUNCTION 'REUSE_ALV_BLOCK_LIST_INIT'
    EXPORTING
      i_callback_program = sy-repid.

  "Prepare field catalog for MARA
  PERFORM build_fieldcat USING 'MARA' it_fieldcat.

  "Append MARA list
  CALL FUNCTION 'REUSE_ALV_BLOCK_LIST_APPEND'
    EXPORTING
      is_layout   = VALUE slis_layout_alv( colwidth_optimize = 'X' )
      it_fieldcat = it_fieldcat
      it_events   = lt_events
      i_tabname   = 'MARA'
      i_text     = 'Material Master - MARA'
    TABLES
      t_outtab    = it_mara.


  CLEAR it_fieldcat.

  "Prepare field catalog for MARC
  PERFORM build_fieldcat USING 'MARC' it_fieldcat.

  "Append MARC list
  CALL FUNCTION 'REUSE_ALV_BLOCK_LIST_APPEND'
    EXPORTING
      is_layout   = VALUE slis_layout_alv( colwidth_optimize = 'X' )
      it_fieldcat = it_fieldcat
      i_tabname   = 'MARC'
      i_text     = 'Plant Data - MARC'
      it_events   = lt_events
    TABLES
      t_outtab    = it_marc.

  "Display ALV Block List
  CALL FUNCTION 'REUSE_ALV_BLOCK_LIST_DISPLAY'.



  "--- Create field catalog helper form
FORM build_fieldcat USING p_table TYPE string
                          p_fieldcat TYPE slis_t_fieldcat_alv.

  DATA ls_fcat TYPE slis_fieldcat_alv.
  CLEAR ls_fcat.

  IF p_table = 'MARA'.
    ls_fcat-fieldname = 'MATNR'. ls_fcat-seltext_m = 'Material'. APPEND ls_fcat TO p_fieldcat.
    ls_fcat-fieldname = 'MTART'. ls_fcat-seltext_m = 'Material Type'. APPEND ls_fcat TO p_fieldcat.
    ls_fcat-fieldname = 'MBRSH'. ls_fcat-seltext_m = 'Industry'. APPEND ls_fcat TO p_fieldcat.
  ELSEIF p_table = 'MARC'.
    ls_fcat-fieldname = 'MATNR'. ls_fcat-seltext_m = 'Material'. APPEND ls_fcat TO p_fieldcat.
    ls_fcat-fieldname = 'WERKS'. ls_fcat-seltext_m = 'Plant'. APPEND ls_fcat TO p_fieldcat.
    ls_fcat-fieldname = 'DISMM'. ls_fcat-seltext_m = 'MRP Type'. APPEND ls_fcat TO p_fieldcat.
  ENDIF.

ENDFORM. 

· It can be a:

• Data element (e.g., MATNR)
• Structure (e.g., SFLIGHT)
• Custom type created via TYPES

Example:

TYPES: BEGIN OF ty_line,

matnr TYPE matnr,

maktx TYPE maktx,

END OF ty_line.

Here,

ty_line is the line type — it represents the structure of a single row.

A table type defines the entire internal table, including:

• Line type
• Access method (standard, sorted, hashed)
• Unique/non-unique keys

Example:TYPES: ty_table TYPE STANDARD TABLE OF ty_line WITH DEFAULT KEY.

Here:

· ty_line is the line type (structure of each row)

· ty_table is the table type (definition of the whole table)

Difference Between Line Type and Table Type

Purpose:
This event is triggered before the selection screen is displayed to the user.

Use Case:
To modify the selection screen dynamically — for example, to hide/show fields, enable/disable them, or set default values based on conditions.

AT SELECTION-SCREEN OUTPUT.
LOOP AT SCREEN.
IF p_radio1 = 'X'.
IF screen-name = 'P_FIELD2'.
screen-active = '0'. "Disable the field
MODIFY SCREEN.
ENDIF.
ENDIF.
ENDLOOP.

AT SELECTION-SCREEN.
IF p_date < sy-datum.
MESSAGE 'Date cannot be in the past' TYPE 'E'.
ENDIF.

Classical Reports

• Simplest and most basic report type.
• Output is in line-by-line format using WRITE statements.
• Limited formatting, but supports interactive features like AT LINE-SELECTION.

Used for: Simple lists, master data overviews, basic reporting.

Interactive Reports

• Extension of classical reports.
• Allows drill-down capability: click on a row to see detailed data (secondary list).
• Can have up to 20 secondary lists.

Used for: Master-detail views, like viewing sales orders from a list of customers.

 Key event: AT LINE-SELECTION

ALV Reports (ABAP List Viewer)

• Provides a powerful, flexible, and interactive table display.
• Includes sorting, filtering, exporting, column formatting, etc.
• Can be simple ALV, ALV Grid, or ALV with OO (Object-Oriented) approach.

Used for: Complex and user-friendly reporting.

Main function modules/classes:

• REUSE_ALV_GRID_DISPLAY
• CL_GUI_ALV_GRID
• CL_SALV_TABLE (for OO ALV)