sap-btp

1. BTP Landscape Structure

Global Account
└── Subaccount (region-specific)
    ├── Cloud Foundry (CF) Environment
    │   └── Spaces → CF Applications + Service Instances
    ├── Kyma Environment
    │   └── Namespaces → Pods / Serverless Functions
    └── BTP ABAP Environment
        └── ABAP Instances (Clean Core ABAP development)

Key platform services:

Service	Purpose
XSUAA	OAuth 2.0 authorization server — user auth + service-to-service
Destination Service	Connection config to backend systems (S/4HANA, etc.)
Connectivity Service	On-premise access via Cloud Connector (SCC)
Event Mesh	Async event-driven messaging between applications
HANA Cloud	Managed SAP HANA database service
Alert Notification	Event-based alerting and notification

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2. CAP (Cloud Application Programming Model)

Project Structure

my-cap-project/
├── db/
│   └── schema.cds         ← Data model (entities, associations)
├── srv/
│   ├── service.cds        ← Service definition (projection, actions, functions)
│   └── service-impl.js    ← Custom event handlers (Node.js)
│   └── service-impl.java  ← Custom handlers (Java alternative)
├── app/
│   └── fiori-app/         ← Fiori Elements UI (optional)
├── mta.yaml               ← Multi-target application deployment descriptor
└── package.json           ← Node.js dependencies + CDS config

Essential Commands

cds init my-project          # Scaffold new CAP project
cds watch                    # Local dev server with mock data + live reload
cds build                    # Compile CDS → HANA artifacts + OData metadata
cds deploy --to hana         # Deploy DB schema to HANA Cloud
cf push                      # Deploy to Cloud Foundry
mbt build && cf deploy *.mtar # MTA build + deploy (recommended for production)

Custom Handler Patterns (Node.js)

module.exports = cds.service.impl(async function () {
  const db = await cds.connect.to('db');

  // Before hook — validate input
  this.before('CREATE', 'MyEntity', async (req) => {
    if (!req.data.CompanyCode) req.reject(400, 'CompanyCode is required');
  });

  // On hook — custom read logic
  this.on('READ', 'MyEntity', async (req) => {
    return db.run(req.query);
  });

  // Remote service call to S/4HANA
  this.on('getStock', async (req) => {
    const s4 = await cds.connect.to('S4HANA_MM');
    return s4.run(SELECT.from('A_MaterialStock').where({ Plant: req.data.Plant }));
  });
});