eventemitter-super
v1.0.9
Published
An event emitter/listener tool based on EventEmitter3.
Maintainers
roman_123Readme
eventemitter-super
An event emitter/listener tool based on EventEmitter3.
Setup
Node
npm install --save eventemitter-superBrowser
<script src="./lib/eventemitter-super.umd.js"></script>Usage
You can use it as a browser global or as a CommonJS/ESM module.
// Browser global
var eventBus = new EventTool.EventEmitterSuper()
// CommonJS
const EventEmitterSuper = require('eventemitter-super')
const bus1 = new EventEmitterSuper()
// ES module
import EventEmitterSuper from 'eventemitter-super'
const bus2 = new EventEmitterSuper()Examples
// Aliases of common methods:
// bindOnce(once), bind(on), fire(emit), unbind(off), un(off), addOnceListeners(onceEvents)Example 1 - Return a disposer function
import EventEmitterSuper from 'eventemitter-super'
const eventBus = new EventEmitterSuper()
const destroyEvent = eventBus.on('event1', () => {
console.log('event1 fired')
})
destroyEvent() // destroy listenerExample 2 - HTML element event listener
const eventBus = new EventEmitterSuper()
const div = document.getElementById('test-div')
const destroyEvent = eventBus.addHtmlListener(div, 'click', () => {})
destroyEvent()Example 3 - Debounce and throttle listeners
// Debounce
const eventBus = new EventEmitterSuper()
const destroyDebounce = eventBus.onDebounce('event1', function () {
console.log('event1', arguments)
}, 1000, null)
const timer1 = setInterval(() => {
eventBus.fire('event1', 1, 2, 3)
}, 100)
setTimeout(() => {
clearInterval(timer1)
destroyDebounce()
}, 5000)
// Throttle
const destroyThrottle = eventBus.onThrottle('event2', function () {
console.log('event2', arguments)
}, 1000, null)
const timer2 = setInterval(() => {
eventBus.fire('event2', 1, 2, 3)
}, 100)
setTimeout(() => {
clearInterval(timer2)
destroyThrottle()
}, 5000)Example 4 - HTML event debounce and throttle
<body>
<button id="btn">click me</button>
<button id="btn2">stop listen</button>
<script src="./lib/eventemitter-super.umd.js"></script>
<script>
const eventBus = new EventTool.EventEmitterSuper()
const btn = document.getElementById('btn')
const btn2 = document.getElementById('btn2')
const destroyBtn = eventBus.onDebounceHtmlEvent(btn, 'click', () => {
console.log('click btn')
}, 1000, null)
eventBus.onHtmlEvent(btn2, 'click', () => {
destroyBtn()
}, null)
</script>
</body>Example 5 - Wait for multiple events once
const eventBus = new EventEmitterSuper()
eventBus.onceEvents(['event1', 'event2'], () => {
console.log('event1 and event2')
})
setTimeout(() => eventBus.emit('event2'), 1000)
setTimeout(() => eventBus.emit('event1'), 2000)Example 6 - Trigger callback after N executions
const eventBus = new EventEmitterSuper()
eventBus.onceByExecCount('test', () => {
console.log('event emitted')
}, 3)
eventBus.emit('test')
eventBus.emit('test')
eventBus.emit('test')Example 7 - Max wait time fallback
const eventBus = new EventEmitterSuper()
eventBus.onceWithMaxWaitTime('test', () => {
console.log('event emitted')
}, 3000)
eventBus.onceEventsWithMaxWaitTime(['test1', 'test2'], () => {
console.log('event emitted')
}, 3000)
eventBus.onceEventsWithMaxWaitTime(['test1', 'test1'], () => {
console.log('event emitted')
}, 3000)Example 8 - Promise wrappers
// Promise wrapper methods
// oncePromise
// onceEventsPromise
// onceByExecCountPromise
// onceWithMaxWaitTimePromise
// onceEventsWithMaxWaitTimePromise
async function test1() {
const res = await eventBus.oncePromise('test')
console.log(res)
}
test1()
setTimeout(() => {
eventBus.emit('test', 'eventobj1', 'eventobj2')
}, 3000)
async function test2() {
const res = await eventBus.onceWithMaxWaitTimePromise('test1', 3000)
console.log(res)
}
test2()
setTimeout(() => {
eventBus.emit('test1', 'eventobj1', 'eventobj1')
}, 1000)Example 9 - Wait for all listeners with emitPromise
import { EventEmitterSuper } from 'eventemitter-super'
const eventBus = new EventEmitterSuper()
eventBus.on('task', async (id) => {
await new Promise((resolve) => setTimeout(resolve, 800))
console.log('async listener done:', id)
})
eventBus.on('task', (id) => {
console.log('sync listener done:', id)
})
async function run() {
console.log('before emitPromise')
await eventBus.emitPromise('task', 1001)
console.log('after emitPromise')
}
run()Example 10 - Catch errors from emitPromise
import { EventEmitterSuper } from 'eventemitter-super'
const eventBus = new EventEmitterSuper()
eventBus.on('task', async () => {
await new Promise((resolve) => setTimeout(resolve, 200))
throw new Error('listener failed')
})
eventBus.on('task', () => {
console.log('another listener finished')
})
async function run() {
try {
await eventBus.emitPromise('task')
console.log('all listeners completed')
} catch (err) {
console.error('emitPromise failed:', err.message)
}
}
run()