# EventBus

A basic implementation of a pub/sub mechanism enabling loosely coupled between the host application and the modules.

# Reference 

const eventBus = new EventBus(options?: { logger? })

# Parameters

  • options: An optional object literal of options:
    • logger: An optional logger to facilitate debugging.

# Methods

  • addListener(eventName, callback, options?): Register the callback event listener for eventName.
  • removeListener(eventName, callback, options?): Remove the callback event listener for eventName.
  • dispatch(eventName, payload?): Dispatch an event to the listeners of eventName.

# Usage

# Create an event bus instance 

import { EventBus, RuntimeLogger } from "@squide/firefly";

const eventBus = new EventBus({
    logger: new RuntimeLogger([])
});

# Add a listener 

import { useCallback } from "react";

const handleFoo = useCallback((data, context) => {
    // do something...
}, [];

// Listen to every "foo" events.
eventBus.addListener("foo", handleFoo);

// Listen to the first "foo" event, then automatically remove the listener.
eventBus.addListener("foo-once", handleFoo, { once: true });

# Remove a listener 

// Remove a regular listener.
eventBus.removeListener("foo", handleFoo);

// Remove a listener created with the `once` option.
eventBus.removeListener("foo-once", handleFoo, { once: true });

# Dispatch an event 

eventBus.dispatch("foo", "bar");