@ApiFunctionSubscriber

Registers a class as a function-level subscriber for a specific entity. Subscribers receive hooks whenever observable services execute CRUD functions (before, after, error for create/update/delete/get/getList/getMany).

Signature

@ApiFunctionSubscriber<E extends IApiBaseEntity>({
	entity,
	priority?,
}: IApiFunctionSubscriberProperties<E>)

Options

Usage steps

1. Mark the target service with @ApiServiceObservable() so hooks are emitted.
2. Extend ApiFunctionSubscriberBase<E> and override desired lifecycle methods (onBeforeCreate, onAfterUpdate, onAfterErrorDelete, etc.).
3. Decorate the subscriber class with @ApiFunctionSubscriber.

Example

@Injectable()
@ApiFunctionSubscriber<PostEntity>({ entity: PostEntity, priority: 50 })
export class PostSlugSubscriber extends ApiFunctionSubscriberBase<PostEntity> {
	async onBeforeCreate(context: TApiSubscriberFunctionBeforeCreateContext<PostEntity>) {
		context.result.body.slug = this.slugify(context.result.body.title);
		return context.result;
	}
}

Related resources

• Subscriber Decorators overview
• Subscriber System – Function Subscribers