icecast-metadata-player/src/EventTargetPolyfill.js

Simple to use Javascript class that plays an Icecast stream with real-time metadata updates

// support for Safari 13
// https://stackoverflow.com/a/58209729/14911733

export default class EventTargetPolyfill {
  constructor() {
    this._listeners = [];
  }

  hasEventListener(type, listener) {
    return this._listeners.some(
      (item) => item.type === type && item.listener === listener,
    );
  }

  addEventListener(type, listener, options = {}) {
    if (!this.hasEventListener(type, listener)) {
      this._listeners.push({ type, listener, options });
    }
    // console.log(`${this}-listeners:`,this._listeners);
    return this;
  }

  removeEventListener(type, listener) {
    const index = this._listeners.findIndex(
      (item) => item.type === type && item.listener === listener,
    );
    if (index >= 0) this._listeners.splice(index, 1);
    return this;
  }

  removeEventListeners() {
    this._listeners = [];
    return this;
  }

  dispatchEvent(evt) {
    this._listeners
      .filter((item) => item.type === evt.type)
      .forEach((item) => {
        const {
          type,
          listener,
          options: { once },
        } = item;
        listener.call(this, evt);
        if (once === true) this.removeEventListener(type, listener);
      });
    return this;
  }
}