[FEATURE] Ability to inject `outboxed` service

[hakimio]

Description

Would be nice to be able to directly inject outboxed service. TS types for cds.outboxed() were introduced in cds-types v0.3.0-beta.1.

Suggested solution

    @Inject(CDS_DISPATCHER.OUTBOXED_SRV)
    private readonly outboxedSrv: Service;

[dragolea]

I've never used this cds.outboxed, pls, give me a very simple use case so I know what's all about.

[hakimio]

Basically it allows you to:

• save events in your database
• replay/resend them in case of an error
• monitor events for errors
• have truly asynchronous events. The transactions in your event handler will no longer be tied to transactions in your event emitter. If event handler fails, it will not have any effect on event emitter.

EDIT: Unfortunately, cds-types v0.2.0 which works with cds v7 does not define cds.outboxed() function.

[dragolea]

Let's leave it open. Somehow the new version of cds@8 and all related packages like cds-types are not in great shape in terms of typescript, they have removed a lot of types in the new version.

[hakimio]

Ok, if anyone else wants to use outboxed() with cds v7 and cds-types v0.2.0, here is the type definition for outboxed():

declare module '@sap/cds' {
    import {Service} from '@cap-js/cds-types';

    export * from '@cap-js/cds-types';
    export declare const outboxed: (service: Service) => Service;
}

[dragolea]

Ok, just did a small feasability check, and this should not be that hard to implement. If you follow this feature in the new cds-types package, let me know once it's there and I will start impelemnting it.

[hakimio]

The type is already in the new cds-types package, starting with v0.3.0-beta.1. The only problem is that cds-types v0.3.0+ is not compatible with cds v7.

https://github.com/cap-js/cds-types/blob/526cbb1be82afdc3377469509278e546d71b9088/apis/services.d.ts#L452

[dragolea]

Ok, understood, once we have a stable cds-types I will work on this new feature.

[lianas10tb]

Help me do this