EventAggregator

Usage

import in TypeScript

import {EventAggregator, debounce} from "eventaggregator";

import in JavaScript

const ea = require("eventaggregator");
const EventAggregator = ea.EventAggregator;
const debounce = ea.debounce;

get an instance

const ea = EventAggregator.getInstance("dom"); // acts like a Singleton

const ea = new EventAggregator();

emit an event

window.addEventListener("resize", event => ea.emit("resize", event));

subscribe to an event

ea.on("resize", (data: any, event: string): void => {
  // do something on resize
});

subscribe to only the first event

ea.once("resize", (data: any, event: string): void => {
  // do something on the first resize event
});

unsubscribe a subscription

const sub = ea.on("resize", (data: any, event: string): void => {...});
sub.off();

subscribe to all events of the EventAggregator

ea.on("*", (data: any, event: string): void => {
  // handle all events
  // event holds the original event name, for example: "resize"
});

multiple event subscriptions

const subs = ea.on(["click", "touchstart"], (data: any, event: string): void => {...});
subs.off();

remove all event subscriptions

ea.off("resize")
// or
ea.off(["click", "touchstart"])

throttle an event

ea.on("very-frequent-event", throttle((data: any, event: string): void => {
  // handle the events with a maximum of one per 500 milliseconds (default threshhold is 100 milliseconds)
}, 500));

debounce an event

ea.on("very-frequent-event", debounce((data: any, event: string): void => {
  // handle the last event and only if the event has been silence for 500 milliseconds (default threshhold is 100 milliseconds)
}, 500));