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January Release ​

Welcome to the January 2024 release of CAP. Find the most noteworthy news and changes in the following sections.

Open Telemetry Plugin ​

The Telemetry plugin @cap-js/telemetry provides observability features such as tracing and metrics, including automatic OpenTelemetry instrumentation. Simply add the plugin to your project and you will find telemetry output written to the console as follows:

txt
[odata] - GET /odata/v4/processor/Incidents
[telemetry] - elapsed times:
  0.00 → 2.85 = 2.85 ms  GET /odata/v4/processor/Incidents
  0.47 → 1.24 = 0.76 ms    ProcessorService - READ ProcessorService.Incidents
  0.78 → 1.17 = 0.38 ms      db - READ ProcessorService.Incidents
  0.97 → 1.06 = 0.09 ms        @cap-js/sqlite - prepare SELECT json_object('ID',ID,'createdAt',createdAt,'creat…
  1.10 → 1.13 = 0.03 ms        @cap-js/sqlite - stmt.all SELECT json_object('ID',ID,'createdAt',createdAt,'crea…
  1.27 → 1.88 = 0.61 ms    ProcessorService - READ ProcessorService.Incidents.drafts
  1.54 → 1.86 = 0.32 ms      db - READ ProcessorService.Incidents.drafts
  1.74 → 1.78 = 0.04 ms        @cap-js/sqlite - prepare SELECT json_object('ID',ID,'DraftAdministrativeData_Dra…
  1.81 → 1.85 = 0.04 ms        @cap-js/sqlite - stmt.all SELECT json_object('ID',ID,'DraftAdministrativeData_Dr…

In addition to the default console output, there are predefined kinds for exporting telemetry data to SAP Cloud Logging, Dynatrace, and Jaeger.

See the repository's README for more details.Learn more about Java support.

CDS Language & Compiler ​

Define Event by Projection ​

You can now define an event as projection on an entity, type, or another event. This is useful, for example, when importing services: it allows to define an event in CAP as projection on the "external" event.

Example:

cds
event CustomerChanged : projection on ImportedService.BusinessPartner.ChangedEvent {
  BusinessPartner as ID,
  BusinessPartnerFullName as name,
  // ...
}

Only the effective signature of the projection is relevant.

Learn more about Events.

Node.js ​

Media Data and Large Binaries ​

Previously, the database services returned cds.LargeBinary without @Core.MediaType annotation as regular column with base64-encoded buffer as value which potentially causes problems in memory consumption.

As a consequence, from now on the database services will return large binaries only if requested explicitly and as a stream instead of the materialized buffer.

This has the following effect:

js
SELECT.from(Attachments) // [!code --] //> [{ ID, title, image: Buffer }]
SELECT(['image']).from(Attachments) // [!code --] //> [{ image: Buffer }]

SELECT.from(Attachments) // [!code ++] //> does not include "image"
SELECT(['image']).from(Attachments) // [!code ++] //> [{ image: <media stream> }]

This also has an effect for OData APIs. Large binaries have to be annotated with @Core.MediaType in order to be reachable via the streaming choreography. If not annotated, those properties are not reachable anymore, even if requested explicitely.

cds.stream() and srv.stream() are deprecated and will be removed with the next major release. SELECT with a single large binary column can be used instead as described above.

Compatibility to the previous behavior can be restored with

json
"cds": {
  "features": {
    "stream_compat": true
  }
}

TIP

It is strongly recommended to annotate all large binary properties with @Core.MediaType and use them according to streaming scenarios.

Learn more about streaming.Learn more about databases.

Programmatic Outboxing of Services ​

You can now use cds.outboxed(srv) to get the outboxed variant of a service: Each event first gets stored in an outbox before reaching the target service. For immediate emits of outboxed services, there's also the counterpart cds.unboxed(srv).

js
const outboxed = cds.outboxed(srv)
await outboxed.emit('someEvent', { some: 'message' }) //> deferred emit via outbox
await cds.unboxed(outboxed).emit('someEvent', { some: 'message' }) //> immediate emit w/o outbox

Learn more about the outbox in Node.js.

Lean Draft Sorting on SAP Fiori List Report Floorplan ​

The sorting behavior for the lean draft has been aligned with the other runtimes in the SAP ecosystem, such as CAP Java and RAP for a consistent user experience.

Instead of positioning the drafts always on top of the list, they are now included at the respective position of the actual sorting order.

Garbage Collection of Stale Drafts ​

Stale drafts can be deleted automatically after a configurable timeout. Simply set the timeout to true (enables default timeout of 30d) or a value like 14d.

json
{
  "cds": {
    "fiori": {
      "draft_deletion_timeout": "14d"
    }
  }
}

Learn more about general draft handling in Node.js.

Java ​

Important ❗️ ​

Support for Cloud SDK 5 ​

CAP Java supports Cloud SDK 5 now.

In case your application uses Cloud SDK integration (cds-integration-cloud-sdk), the migration is a matter of adapting Maven dependencies only.

Migrate to Cloud SDK 5 as soon as possible

We highly recommend to migrate to Cloud SDK 5 as soon as possible as Cloud SDK 4 runs out of maintenance end of May 24 according to the release policy.

You can find detailed instructions in the dedicated migration guide.

Comparing CDS Elements ​

When comparing CdsElement instances obtained from the CdsModel the equals method must now be used.

Support for Spring Boot 3.2 ​

CAP Java now supports latest Spring Boot 3.2.

The most interesting feature is virtual thread support. To use virtual threads, you need to run with JDK 21 and set the property spring.threads.virtual.enabled to true.

Note that HANA JDBC driver processes Input/Output in synchronized blocks which can reduce the effect of virtual threads. Experiments are currently being carried out with an internal driver version optimized for virtual threads. Stay tuned!

Enhanced Open Telemetry ​

When configured with a front end for Open Telemetry signals, CAP Java now additionally writes trace spans for the following:

  • Individual OData V4 requests of a $batch request.
  • CQN processing showing detailed statement information.

Moreover, Dynatrace as Open Telemetry front end is integrated smoothly now.

Dynatrace

Learn more about Open Telemetry in CAP Java.

Update with Expressions in Fluent Style ​

Use the model interfaces of the builder API to build update expressions in fluent style. The following statements converts a book's title to upper case and increases the stock by 1:

java
CqnUpdate update = Update.entity(BOOK).where(b -> b.title().eq("CAP"))
    .set(b -> b.title(), title -> title.toUpper())
    .set(b -> b.stock(), stock -> stock.plus(1));

Learn more about building update expressions.

Improvements in Search on SAP HANA Cloud HEX Engine ​

On SAP HANA Cloud, in SQL optimization mode hex, CAP Java uses the SCORE function instead of the CONTAINS predicate to execute a search.

Compared to CONTAINS, SCORE has more capabilities, listed in the following:

  • can be executed by the SAP HANA HEX engine
  • can search expressions
  • can search subqueries

This allows to significantly simplify the generated SQL in hex mode, which brings performance improvements in many situations.

Annotate an entity with @cds.sql.search.mode to specify how an entity should be searched. Ths following list contains possible values:

  • generic - search using LIKE
  • localized-associations - for localized elements, the translation and the fallback text are searched
  • localized-view - for localized elements, the translation is searched or the fallback text if no translation is available

Learn more about SQL optimization mode.

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