August 2022 ​

CAP on Kyma/K8s ​

Important Changes ❗️ ​

New Component Minimum Version ​

The latest version of the CAP Helm chart (cds add helm) introduces new minimum version requirements for the following components:

Don't Use CDS_ENVIRONMENT_K8S_SERVICEBINDINGS_* Environment Variables ​

Make sure that no environment variables starting with CDS_ENVIRONMENT_K8S_SERVICEBINDINGS_ are in your chart/values.yaml file of your Helm chart, as they conflict with the new service bindings.

These variables were previously added by the cds add helm:connectivity command.

CAP Java Support for servicebinding.io Service Bindings ​

CAP Java now makes use of the new open source Service Binding Access library as default source to obtain service bindings. On K8s/Kyma it integrates better with the SAP BTP Service Operator, which uses a servicebinding.io based format. This allows reading service bindings with the same set of metadata as in Cloud Foundry, which makes it fully transparent to the CAP application if the service bindings are read in the K8s/Kyma or Cloud Foundry environment.

Configure Resources for Content Deployment Jobs ​

You can now configure the Kubernetes resources for HTML5 application and HANA deployment jobs.

The default configuration is added by running cds add helm.

Add Environment Variables for Content Deployment Jobs ​

HTML5 application and SAP HANA deployment jobs allow adding environment variables.

For example, the following snippet from the Helm chart adds an environment variable DEBUG with value * to the HTML5 applications deployer job:

html5_apps_deployer:
  env:
    DEBUG: '*'

html5_apps_deployer:
  env:
    DEBUG: '*'

Schema Validation ​

The Helm chart now contains a JSON schema that helm uses to validate the values.yaml file. Development tools, such as Visual Studio Code, can use the schema to show validation errors, descriptions and suggestions.

Improved VS Code Support for CDS Configuration ​

Code completion and validation for the cds configuration has been improved in VS Code. In both package.json and .cdsrc.json, you get hints on the possible values plus warnings for invalid values based on the installed @sap/cds version. Especially filling out the cds.requires section is now much easier.

CDS Language & Compiler ​

SAP HANA Regex Functions ​

CDS natively supports the SAP HANA Regex functions locate_regexpr, occurrences_regexpr, replace_regexpr, and substring_regexpr:

entity Foo as select from Bar {
  /* ... */
  substring_regexpr(pattern in name from 5) as sub
};

entity Foo as select from Bar {
  /* ... */
  substring_regexpr(pattern in name from 5) as sub
};

Learn more about Native Database Functions.

Actions and Functions in Aspects ​

Aspects now can have bound actions and functions:

aspect TravelActions { }
  actions {
    action rejectTravel();
    action acceptTravel();
    function isValid() returns Boolean;
  }

aspect TravelActions { }
  actions {
    action rejectTravel();
    action acceptTravel();
    function isValid() returns Boolean;
  }

Reuse these aspects for example in services:

service TravelService {
  entity Travel as projection on my.Travel;
  extend Travel with TravelActions;
}

service TravelService {
  entity Travel as projection on my.Travel;
  extend Travel with TravelActions;
}

Learn more about Aspects.

Java SDK ​

Important Changes ❗️ ​

Minimum Spring Boot Version 2.7.x ​

• CAP Java SDK now requires Spring Boot version 2.7.x or later. Most notably the deprecated WebSecurityConfigurerAdapter has been migrated to SecurityFilterChain in CAP Java. As both can't coexist, custom security configurations in applications need to be migrated to SecurityFilterChain as well. See an example in our documentation. In addition, Spring Boot 2.7.x defaults to H2 version 2.x, which is not fully compatible with DDL artifacts generated by CDS compiler. If you use H2, make sure to pin your application to H2 version 1.x as shown in the bookshop example. In addition, read the Spring Boot upgrade instructions.

• The deprecated path access via CdsData::get has been removed. Instead use data.getPath("deeply.nested.key") to access values in deeply nested maps.

Error Response Handler ​

Exceptions thrown during event handler processing, are caught by OData V2 and V4 protocol adapters and are turned into corresponding OData error responses. So far, it wasn't possible to change error responses as exceptions were thrown by the framework. Now, you can customize these responses by handling the ERROR_RESPONSE event of the Application Lifecycle Service emitted by the protocol adapter. You can control the error message text, code and the list of messages collected during request processing for specific or general error situations. The following example demonstrates how to change the error text of authorization errors:

@Component
@ServiceName(ApplicationLifecycleService.DEFAULT_NAME)
public class SimpleExceptionHandler implements EventHandler {

  @After
  public void overrideMissingAuthMessage(ErrorResponseEventContext context) {
    if (context.getException().getErrorStatus().equals(CdsErrorStatuses.EVENT_FORBIDDEN)) {
        context.getResult().getMessages().set(0,
            Message.create(Severity.ERROR, "You cannot execute this action"));
    }
  }
}

@Component
@ServiceName(ApplicationLifecycleService.DEFAULT_NAME)
public class SimpleExceptionHandler implements EventHandler {

  @After
  public void overrideMissingAuthMessage(ErrorResponseEventContext context) {
    if (context.getException().getErrorStatus().equals(CdsErrorStatuses.EVENT_FORBIDDEN)) {
        context.getResult().getMessages().set(0,
            Message.create(Severity.ERROR, "You cannot execute this action"));
    }
  }
}

Find the details in our documentation.

<dependency>
    <groupId>com.sap.cds</groupId>
    <artifactId>cds-feature-redis</artifactId>
</dependency>

<dependency>
    <groupId>com.sap.cds</groupId>
    <artifactId>cds-feature-redis</artifactId>
</dependency>

cds:
  messaging.services:
    my-redis-service:
      kind: redis-pubsub

cds:
  messaging.services:
    my-redis-service:
      kind: redis-pubsub

entity Books : cuid {
  title         : String;
  content       : LargeString @Core.MediaType: 'text/plain';
}

entity Books : cuid {
  title         : String;
  content       : LargeString @Core.MediaType: 'text/plain';
}

Books book = Books.create(201);
Integer bookId = book.getId(); // 201

Books book = Books.create(201);
Integer bookId = book.getId(); // 201

await SELECT.from('sqlite_master')
await cds.read('sqlite_master')

await SELECT.from('sqlite_master')
await cds.read('sqlite_master')

await SELECT.from('Books')
await cds.read('Books')

await SELECT.from('Books')
await cds.read('Books')

const Books = 'sap.capire.bookshop.Books'
await SELECT.from(Books)
await cds.read(Books)

const Books = 'sap.capire.bookshop.Books'
await SELECT.from(Books)
await cds.read(Books)

const {Books} = cds.entities ('sap.capire.bookshop')
await SELECT.from(Books)
await cds.read(Books)

const {Books} = cds.entities ('sap.capire.bookshop')
await SELECT.from(Books)
await cds.read(Books)

{
  SELECT: {
    from: [{ ref: ['Books'] }],
    search: [{ val: 'wut' }]
  }
}

{
  SELECT: {
    from: [{ ref: ['Books'] }],
    search: [{ val: 'wut' }]
  }
}