API Reference > bentleyjs-core > Events > BeEvent > addOnce addOnce Method Registers a callback function to be executed only once when the event is raised. addOnce(listener: T extends Listener, scope?: any): () => void see BeEvent.raiseEvent, BeEvent.removeListener Parameter Type Description listener T extends Listener The function to be executed once when the event is raised. scope any An optional object scope to serve as the this pointer in which the listener function will execute. Returns - () => void A function that will remove this event listener. Defined in core/bentley/src/BeEvent.ts Line 51 Last Updated: 13 June, 2024