Fabians
40 lines
879 B
JavaScript
40 lines
879 B
JavaScript
/*
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* https://medium.com/better-programming/how-to-create-your-own-event-emitter-in-javascript-fbd5db2447c4
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*/
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export default class EventEmitter {
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constructor() {
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this._events = {}
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}
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on(name, listener) {
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if (!this._events[name]) {
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this._events[name] = []
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}
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this._events[name].push(listener)
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}
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removeListener(name, listenerToRemove) {
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if (!this._events[name]) return
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const filterListeners = (listener) => listener !== listenerToRemove
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this._events[name] = this._events[name].filter(filterListeners)
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}
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// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters
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emit(name, ...args) {
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if (!this._events[name]) return
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const fireCallbacks = (callback) => {
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callback(...args)
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}
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this._events[name].forEach(fireCallbacks)
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}
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dispose() {
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this._events = null
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}
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}
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