diff --git a/public/scripts/lite-yt-embed.js b/public/scripts/lite-yt-embed.js index 591954b..78cefd0 100644 --- a/public/scripts/lite-yt-embed.js +++ b/public/scripts/lite-yt-embed.js @@ -10,229 +10,4 @@ * https://github.com/Daugilas/lazyYT * https://github.com/vb/lazyframe */ -class LiteYTEmbed extends HTMLElement { - connectedCallback() { - this.videoId = this.getAttribute('videoid'); - - let playBtnEl = this.querySelector('.lty-playbtn'); - // A label for the button takes priority over a [playlabel] attribute on the custom-element - this.playLabel = (playBtnEl && playBtnEl.textContent.trim()) || this.getAttribute('playlabel') || 'Play'; - - this.dataset.title = this.getAttribute('title') || ""; - - /** - * Lo, the youtube poster image! (aka the thumbnail, image placeholder, etc) - * - * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md - */ - if (!this.style.backgroundImage) { - this.style.backgroundImage = `url("https://i.ytimg.com/vi/${this.videoId}/hqdefault.jpg")`; - this.upgradePosterImage(); - } - - // Set up play button, and its visually hidden label - if (!playBtnEl) { - playBtnEl = document.createElement('button'); - playBtnEl.type = 'button'; - playBtnEl.classList.add('lty-playbtn'); - this.append(playBtnEl); - } - if (!playBtnEl.textContent) { - const playBtnLabelEl = document.createElement('span'); - playBtnLabelEl.className = 'lyt-visually-hidden'; - playBtnLabelEl.textContent = this.playLabel; - playBtnEl.append(playBtnLabelEl); - } - - this.addNoscriptIframe(); - - // for the PE pattern, change anchor's semantics to button - if(playBtnEl.nodeName === 'A'){ - playBtnEl.removeAttribute('href'); - playBtnEl.setAttribute('tabindex', '0'); - playBtnEl.setAttribute('role', 'button'); - // fake button needs keyboard help - playBtnEl.addEventListener('keydown', e => { - if( e.key === 'Enter' || e.key === ' ' ){ - e.preventDefault(); - this.activate(); - } - }); - } - - // On hover (or tap), warm up the TCP connections we're (likely) about to use. - this.addEventListener('pointerover', LiteYTEmbed.warmConnections, {once: true}); - this.addEventListener('focusin', LiteYTEmbed.warmConnections, {once: true}); - - // Once the user clicks, add the real iframe and drop our play button - // TODO: In the future we could be like amp-youtube and silently swap in the iframe during idle time - // We'd want to only do this for in-viewport or near-viewport ones: https://github.com/ampproject/amphtml/pull/5003 - this.addEventListener('click', this.activate); - - // Chrome & Edge desktop have no problem with the basic YouTube Embed with ?autoplay=1 - // However Safari desktop and most/all mobile browsers do not successfully track the user gesture of clicking through the creation/loading of the iframe, - // so they don't autoplay automatically. Instead we must load an additional 2 sequential JS files (1KB + 165KB) (un-br) for the YT Player API - // TODO: Try loading the the YT API in parallel with our iframe and then attaching/playing it. #82 - this.needsYTApi = this.hasAttribute("js-api") || navigator.vendor.includes('Apple') || navigator.userAgent.includes('Mobi'); - } - - /** - * Add a to the head - */ - static addPrefetch(kind, url, as) { - const linkEl = document.createElement('link'); - linkEl.rel = kind; - linkEl.href = url; - if (as) { - linkEl.as = as; - } - document.head.append(linkEl); - } - - /** - * Begin pre-connecting to warm up the iframe load - * Since the embed's network requests load within its iframe, - * preload/prefetch'ing them outside the iframe will only cause double-downloads. - * So, the best we can do is warm up a few connections to origins that are in the critical path. - * - * Maybe `` would work, but it's unsupported: http://crbug.com/593267 - * But TBH, I don't think it'll happen soon with Site Isolation and split caches adding serious complexity. - */ - static warmConnections() { - if (LiteYTEmbed.preconnected) return; - - // The iframe document and most of its subresources come right off youtube.com - LiteYTEmbed.addPrefetch('preconnect', 'https://www.youtube-nocookie.com'); - // The botguard script is fetched off from google.com - LiteYTEmbed.addPrefetch('preconnect', 'https://www.google.com'); - - // Not certain if these ad related domains are in the critical path. Could verify with domain-specific throttling. - LiteYTEmbed.addPrefetch('preconnect', 'https://googleads.g.doubleclick.net'); - LiteYTEmbed.addPrefetch('preconnect', 'https://static.doubleclick.net'); - - LiteYTEmbed.preconnected = true; - } - - fetchYTPlayerApi() { - if (window.YT || (window.YT && window.YT.Player)) return; - - this.ytApiPromise = new Promise((res, rej) => { - var el = document.createElement('script'); - el.src = 'https://www.youtube.com/iframe_api'; - el.async = true; - el.onload = _ => { - YT.ready(res); - }; - el.onerror = rej; - this.append(el); - }); - } - - /** Return the YT Player API instance. (Public L-YT-E API) */ - async getYTPlayer() { - if(!this.playerPromise) { - await this.activate(); - } - - return this.playerPromise; - } - - async addYTPlayerIframe() { - this.fetchYTPlayerApi(); - await this.ytApiPromise; - - const videoPlaceholderEl = document.createElement('div') - this.append(videoPlaceholderEl); - - const paramsObj = Object.fromEntries(this.getParams().entries()); - - this.playerPromise = new Promise(resolve => { - let player = new YT.Player(videoPlaceholderEl, { - width: '100%', - videoId: this.videoId, - playerVars: paramsObj, - events: { - 'onReady': event => { - event.target.playVideo(); - resolve(player); - } - } - }); - }); - } - - // Add the iframe within