| name | delegate-consumption-view |
| description | Creates @federation.delegate consumption views on remote OData entities in SAP CAP. Use when proxying remote data, adding field renames, association renames, read-only defaults, CUD opt-in, or delegate caching. |
Delegate consumption view
Minimal pattern
using { ProviderService as remote } from '../srv/external/ProviderService';
@federation.delegate
entity Customers as projection on remote.Customers;
Common patterns
Column restriction + renames — excluded fields are never fetched remotely:
@federation.delegate
entity Products as projection on remote.Products {
ID as productId,
name as productName,
price as unitPrice,
currency
};
Association renames — $expand=buyer maps to remote $expand=customer:
@federation.delegate
entity Orders as projection on remote.Orders {
ID as orderId,
customer as buyer,
product as item
};
Static filter — injected into every remote query:
@federation.delegate
entity ActiveCustomers as projection on remote.Customers
where blocked = false;
CUD opt-in (read-only by default)
// All CUD:
@federation.delegate: { writable: true }
entity Products as projection on remote.Products { * };
// Selective:
@federation.delegate: { create: true, update: true }
entity Partners as projection on remote.Partners { ... };
Disabled operations return HTTP 405.
Optional cache
@federation.delegate: { cache: { ttl: 60000 } }
entity CachedCustomers as projection on remote.Customers;
Default strategy is response (requires cds-caching). Use strategy: 'entity' for full-entity SQLite snapshots (requires cds-data-pipeline).
Anti-patterns
❌ Wrong — entity without projection on remote.X:
@federation.delegate
entity Products { key ID: UUID; name: String; }
✅ Correct — always use a consumption view projection.
❌ Wrong — assuming CREATE/UPDATE/DELETE work without write flags.
✅ Correct — explicit writable: true or per-operation flags.
❌ Wrong — hand-written srv.on('READ', ...) for the same entity.
✅ Correct — let the plugin register the delegate handler from the annotation.
Docs
