Embedded YouTube fix

this monitors and auto-refreshes crashed embedded YouTube players in the background for a seamless viewing experience

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         Embedded YouTube fix
// @description  this monitors and auto-refreshes crashed embedded YouTube players in the background for a seamless viewing experience
// @namespace    https://htsign.hateblo.jp
// @version      0.4.1
// @author       htsign
// @match        *://*/*
// @match        https://www.youtube.com/embed/*
// @grant        none
// @license      MIT
// ==/UserScript==

(() => {
  'use strict';

  const ID = 'embedded-youtube-fix';
  const BROKEN_PAGES = [];

  const iframes = document.getElementsByTagName('iframe');

  // parent
  if (window.self === window.top) {
    const visibles = new WeakSet();

    const observer = new IntersectionObserver(entries => {
      for (const { target, isIntersecting } of entries) {
        if (isIntersecting) {
          visibles.add(target);
          target.contentWindow?.postMessage(ID, 'https://www.youtube.com');
        }
        else {
          visibles.delete(target);
        }
      }
    });

    window.addEventListener('message', ({ data, source, origin }) => {
      if (origin !== 'https://www.youtube.com') return;
      if (data !== ID) return;

      const iframe = Array.prototype.find.call(iframes, el => el.contentWindow === source);
      if (iframe == null) return;

      const url = new URL(iframe.src);

      if (url.searchParams.get('feature') === 'oembed') {
        url.searchParams.delete('feature');
      }
      url.searchParams.set(ID, url.searchParams.get(ID) ^ 1);

      if (BROKEN_PAGES.some(pageRegex => pageRegex.test(url.href))) {
        // fallback for cases where copying elements breaks the original site's scripts
        iframe.src = url.toString();
      }
      else {
        // avoid multiple back button presses
        const newIframe = iframe.cloneNode();
        newIframe.src = url.toString();

        iframe.replaceWith(newIframe);
        observer.observe(newIframe);
      }
    });

    const loop = () => {
      for (let i = 0, len = iframes.length; i < len; ++i) {
        const iframe = iframes[i];

        observer.observe(iframe);

        if (visibles.has(iframe)) {
          iframe.contentWindow?.postMessage(ID, 'https://www.youtube.com');
        }
      }

      setTimeout(loop, 500);
    };
    requestIdleCallback(loop);
  }

  // inside of iframe
  else if (location.href.startsWith('https://www.youtube.com/embed/')) {
    window.addEventListener('message', ({ data, source, origin }) => {
      if (data !== ID) return;

      if (document.querySelector('.ytp-error')) {
        source.postMessage(ID, origin);
      }
    });
  }
})();