klf-200-api
Version:
This module provides a wrapper to the socket API of a Velux KLF-200 interface. You will need at least firmware 0.2.0.0.71 on your KLF interface for this library to work.
102 lines • 3.9 kB
JavaScript
;
import debugModule from "debug";
const debug = debugModule(`klf-200-api:TypedEvents`);
/** passes through events as they happen. You will not get events from before you start listening */
/**
* Event emitter class that handles typed events.
*
* @export
* @class TypedEvent<T>
*/
export class TypedEvent {
listeners = [];
listenersOncer = [];
/**
* Adds a listener function to an event emitter.
*
* @param listener Function that is called if the event is emitted.
* @returns {Disposable} Returns a disposable object that should be disposed when not needed anymore.
* @memberof TypedEvent<T>
*/
on = (listener) => {
debug(`TypedEvent on.`);
this.listeners.push(listener);
debug(`${this.listeners.length} listeners registered.`);
return {
dispose: () => this.off(listener),
};
};
/**
* Adds a listener function to an event emitter that is called only once.
*
* @param listener Function that is called only once if the event is emitted.
* @returns {void}
* @memberof TypedEvent<T>
*/
once = (listener) => {
debug(`TypedEvent once.`);
this.listenersOncer.push(listener);
debug(`${this.listenersOncer.length} listeners registered.`);
};
/**
* Removes a listener function from an event emitter.
* If it is called from inside an event handler
* the current event will still call the removed handler
* if it wasn't called so far.
*
* @param listener Function that should be removed.
* @returns {void}
* @memberof TypedEvent<T>
*/
off = (listener) => {
debug(`TypedEvent off.`);
const callbackIndex = this.listeners.indexOf(listener);
if (callbackIndex > -1)
this.listeners.splice(callbackIndex, 1);
debug(`${this.listeners.length} listeners registered.`);
};
/**
* Calls the registered event handler listener functions on after the other.
* The order in which the functions are called is not defined.
*
* @param {T} event The typed event parameter that will be provided to each listener.
* @returns {Promise<void>}
* @memberof TypedEvent<T>
*/
emit = async (event) => {
debug(`TypedEvent emit. ${this.listeners.length} listeners and ${this.listenersOncer.length} once listeners to be called.`);
// Copy all listeners to a temporary array
// in case that an event listener would
// remove itself from the list.
const temporaryListeners = this.listeners.slice();
/** Update any general listeners */
for (const listener of temporaryListeners) {
debug(`Calling Listener ${listener.toString()}.`);
await Promise.resolve(listener(event));
debug(`Listener ${listener.toString()} called.`);
}
// Copy all listeners to a temporary array
// in case that an event listener would
// remove itself from the list.
const temporaryListenersOnce = this.listenersOncer.slice();
/** Clear the `once` queue */
for (const listener of temporaryListenersOnce) {
debug(`Calling Listener Once ${listener.toString()}.`);
await Promise.resolve(listener(event));
debug(`Listener Once ${listener.toString()} called.`);
}
this.listenersOncer = [];
};
/**
* Pipes another event emitter to this event emitter.
*
* @param te Event emitter that is called after this event emitter.
* @returns {Disposable} Returns a disposable object that should be disposed when not needed anymore.
* @memberof TypedEvent<T>
*/
pipe = (te) => {
debug(`TypedEvent pipe.`);
return this.on(async (e) => await te.emit(e));
};
}
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