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@tmrw-realityos/charm / ROSEvent

Class: ROSEvent<T> ​

Simple, type safe, multicast events.

Leaves out the complexity of event bubbling and cancellation.

Uses a naming convention of "on" to register an event listener and "off" to remove it.

Example ​

typescript
class EventHost {
  #currentValue = 0;
  #valueChanged= new ROSEvent<(value: number) => void>();

  mutateState() {
    this.#currentValue = 10;
    this.#valueChanged.dispatch(this.#currentValue);
  }
}

// Observer
const host = new EventHost();
const offChanged = host.#valueChanged.on((value) => {
  console.log("Value changed to", value);
});

function exit() {
  // remove event listener
  if (offChanged) offChanged();
}

Type Parameters ​

• T extends EventHandler

Constructors ​

new ROSEvent() ​

new ROSEvent<T>(): ROSEvent<T>

Returns ​

ROSEvent<T>

Accessors ​

dispatch ​

get dispatch(): (...args) => void

Internal

Returns ​

Function

Parameters ​

• ...args: Parameters<T>

Returns ​

void

Defined in ​

packages/charm/src/helpers/events.ts:75

Methods ​

on() ​

on(callback): RemoveEventListener

Register an event listener.

Parameters ​

• callback: T

Returns ​

RemoveEventListener

A function that will remove the event listener when called.

Parameter ​

callback - The function to be called when the event is dispatched.

Example ​

typescript
const offChanged = host.#onChanged.on((value) => {
  console.log("Value changed to", value);
});

Defined in ​

packages/charm/src/helpers/events.ts:95