VIA API — ABAP Minimal API Framework

VIA API is a high-performance, developer-friendly Minimal API framework for SAP ABAP, heavily inspired by C# ASP.NET Core Minimal APIs and Node.js Express.

Designed for both SAP S/4HANA On-Premise (SICF) and SAP BTP ABAP Environment (Steampunk / Cloud), VIA API allows ABAP developers to build clean, modular, and SOLID-compliant RESTful Web APIs with minimal boilerplate.

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✨ Features

• 🚀 C# Minimal API & Express Ergonomics: Expressive shortcuts (param(), query(), bind(), ok(), created(), bad_request(), not_found(), redirect()).
• 🌐 Dual Deployment: Native support for On-Premise (SICF) via zcl_via_sicf_node and Cloud (SAP BTP) via zcl_via_cloud_node.
• 🔄 Dual-Phase Middleware Pipeline: Intercept HTTP requests before (before) and after (after) handler execution (Response time metrics, Audit logs, Auth, Headers).
• 🧱 Built-in SOLID Architecture: Injected Dependency Container (zif_via_container), Shared Cache (zif_via_cache), and Pluggable Serializers (zif_via_serializer).
• ⚠️ RFC 7807 Problem Details: Standardized HTTP exception handling returning RFC 7807 compliant JSON error payloads.
• ⚡ open-abap & Transpiler Ready: Fully testable locally using @abaplint/transpiler-cli and @abaplint/runtime.

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⚡ Quick Start

1. Define Route Handlers

Create modular local or global route handlers implementing zif_via_handler:

CLASS lcl_get_user_handler DEFINITION.
  PUBLIC SECTION.
    INTERFACES zif_via_handler.
ENDCLASS.

CLASS lcl_get_user_handler IMPLEMENTATION.
  METHOD zif_via_handler~handle.
    DATA(lv_id) = io_context->param( 'id' ).

    IF lv_id = '999'.
      io_context->not_found( 'User does not exist' ).
      RETURN.
    ENDIF.

    io_context->ok( VALUE ty_s_user( id = lv_id name = 'Furkan' role = 'Admin' ) ).
  ENDMETHOD.
ENDCLASS.

2. Register Routes in SICF Node (On-Premise)

CLASS zcl_via_sicf_node IMPLEMENTATION.
  METHOD if_http_extension~handle_request.
    DATA(lo_app) = zcl_via_server=>factory_onprem( server ).

    lo_app->get( iv_path = '/api/v1/users/{id}' io_handler = NEW lcl_get_user_handler( ) ).
    lo_app->post( iv_path = '/api/v1/users'     io_handler = NEW lcl_create_user_handler( ) ).
    lo_app->all( iv_path = '/api/v1/health'     io_handler = NEW lcl_health_handler( ) ).

    lo_app->dispatch( ).
  ENDMETHOD.
ENDCLASS.

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📖 API Reference Cheat Sheet

Request Shortcuts (zif_via_context)

Method	Description	Example
param( name )	Reads a URL path parameter ({id} or {*path})	DATA(lv_id) = c->param( 'id' ).
query( name )	Reads a URL query string parameter	DATA(lv_search) = c->query( 'search' ).
bind( cv_data )	Deserializes JSON body into ABAP data	c->bind( CHANGING cv_user ).
method()	Returns the HTTP request method	DATA(lv_verb) = c->method( ).
path()	Returns the URL request path	DATA(lv_uri) = c->path( ).
client_ip()	Gets client IP from X-Forwarded-For / ~remote_addr	DATA(lv_ip) = c->client_ip( ).
is_json()	Returns abap_true if Content-Type is JSON	IF c->is_json( ).
is_xml()	Returns abap_true if Content-Type is XML	IF c->is_xml( ).
get_header( name )	Reads an HTTP request header	DATA(lv_token) = c->get_header( 'authorization' ).

Response Shortcuts (zif_via_context)

Method	HTTP Code	Response Helper
ok( [data] )	200 OK	c->ok( ls_user ).
created( [uri], [data] )	201 Created	c->created( iv_uri = '/users/1' iv_data = ls_user ).
accepted( [data] )	202 Accepted	c->accepted( ls_job ).
no_content()	204 No Content	c->no_content( ).
bad_request( detail )	400 Bad Request	c->bad_request( 'Invalid email' ).
unauthorized( detail )	401 Unauthorized	c->unauthorized( 'Token expired' ).
forbidden( detail )	403 Forbidden	c->forbidden( 'Access denied' ).
not_found( detail )	404 Not Found	c->not_found( 'User not found' ).
conflict( detail )	409 Conflict	c->conflict( 'User already exists' ).
redirect( url, [perm] )	301/302	c->redirect( '/login' ).
json( data )	200 OK	c->json( ls_data ).
text( string )	200 OK	c->text( 'Hello World' ).
file( bytes, mime, [filename] )	200 OK	c->file( lv_bin, 'application/pdf', 'doc.pdf' ).
download( bytes, filename )	200 OK	c->download( lv_bin, 'export.xlsx' ).

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🔄 Dual-Phase Middleware Pipeline

Middlewares implement zif_via_middleware to intercept requests before and after handler execution:

CLASS zcl_via_mw_logger DEFINITION PUBLIC FINAL CREATE PUBLIC.
  PUBLIC SECTION.
    INTERFACES zif_via_middleware.
ENDCLASS.

CLASS zcl_via_mw_logger IMPLEMENTATION.
  METHOD zif_via_middleware~before.
    " Pre-execution filter / Auth check
    rv_next = abap_true.
  ENDMETHOD.

  METHOD zif_via_middleware~after.
    " Post-execution audit / response logging
    DATA(lv_path) = io_context->get_path( ).
  ENDMETHOD.
ENDCLASS.

Attach middlewares to the server instance:

lo_app->use( NEW zcl_via_mw_logger( ) ).

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🛠️ Testing & Development

Run linter, transpilation, and unit tests using npm:

# Check code style & lints
npm run lint

# Automatically fix lint formatting
npm run fix

# Run ABAP Unit tests
npm run unit

# Launch Express server locally
npm run express

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📄 License

This project is licensed under the MIT License.