@ApiControllerObservable

Marks a controller as observable so its CRUD lifecycle emits events to route subscribers. Without this decorator the subscriber registry ignores the controller even if subscribers are registered.

Signature

@ApiControllerObservable()

Behavior

• Sets the CONTROLLER_API_DECORATOR_CONSTANT.OBSERVABLE_METADATA_KEY metadata flag on the controller class.
• ApiRouteSubscriber instances targeting the same entity receive before, after, and error hooks for each generated route once the flag is present.
• Has no runtime cost unless subscribers exist. Unmarked controllers skip the observable pipeline entirely.

Usage example

@Controller("posts")
@ApiController({
	entity: PostEntity,
	routes: {
		/* ... */
	},
})
@ApiControllerObservable()
export class PostController {}

When to use

• You rely on audit logging, derived DTO changes, or dynamic guard behavior implemented inside ApiRouteSubscriber classes.
• You need deterministic ordering between multiple subscribers via priorities.

Related resources

• Controller Decorators overview
• Subscriber System – Route Subscribers