diff --git a/blocks/embed/lite-yt-embed.css b/blocks/embed/lite-yt-embed.css new file mode 100644 index 00000000..089e1931 --- /dev/null +++ b/blocks/embed/lite-yt-embed.css @@ -0,0 +1,90 @@ +/* copied from https://github.com/paulirish/lite-youtube-embed/releases/tag/v0.2.0 */ +/* stylelint-disable */ + +lite-youtube { + background-color: #000; + position: relative; + display: block; + contain: content; + background-position: center center; + background-size: cover; + cursor: pointer; + max-width: 720px; +} + +/* gradient */ +lite-youtube::before { + content: ''; + display: block; + position: absolute; + top: 0; + background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAADGCAYAAAAT+OqFAAAAdklEQVQoz42QQQ7AIAgEF/T/D+kbq/RWAlnQyyazA4aoAB4FsBSA/bFjuF1EOL7VbrIrBuusmrt4ZZORfb6ehbWdnRHEIiITaEUKa5EJqUakRSaEYBJSCY2dEstQY7AuxahwXFrvZmWl2rh4JZ07z9dLtesfNj5q0FU3A5ObbwAAAABJRU5ErkJggg==); + background-position: top; + background-repeat: repeat-x; + height: 60px; + padding-bottom: 50px; + width: 100%; + transition: all 0.2s cubic-bezier(0, 0, 0.2, 1); +} + +/* responsive iframe with a 16:9 aspect ratio + thanks https://css-tricks.com/responsive-iframes/ +*/ +lite-youtube::after { + content: ""; + display: block; + padding-bottom: calc(100% / (16 / 9)); +} + +lite-youtube > iframe { + width: 100%; + height: 100%; + position: absolute; + top: 0; + left: 0; + border: 0; +} + +/* play button */ +lite-youtube > .lty-playbtn { + width: 68px; + height: 48px; + position: absolute; + cursor: pointer; + transform: translate3d(-50%, -50%, 0); + top: 50%; + left: 50%; + z-index: 1; + background-color: transparent; + /* YT's actual play button svg */ + background-image: url('data:image/svg+xml;utf8,'); + filter: grayscale(100%); + transition: filter .1s cubic-bezier(0, 0, 0.2, 1); + border: none; +} + +lite-youtube:hover > .lty-playbtn, +lite-youtube .lty-playbtn:focus { + filter: none; +} + +/* Post-click styles */ +lite-youtube.lyt-activated { + cursor: unset; +} + +lite-youtube.lyt-activated::before, +lite-youtube.lyt-activated > .lty-playbtn { + opacity: 0; + pointer-events: none; +} + +.lyt-visually-hidden { + clip: rect(0 0 0 0); + clip-path: inset(50%); + height: 1px; + overflow: hidden; + position: absolute; + white-space: nowrap; + width: 1px; +} diff --git a/blocks/embed/lite-yt-embed.js b/blocks/embed/lite-yt-embed.js new file mode 100644 index 00000000..4de5f989 --- /dev/null +++ b/blocks/embed/lite-yt-embed.js @@ -0,0 +1,127 @@ +// Copied from https://github.com/paulirish/lite-youtube-embed/releases/tag/v0.2.0 +/* eslint-disable */ +/** + * A lightweight youtube embed. Still should feel the same to the user, just MUCH faster to initialize and paint. + * + * Thx to these as the inspiration + * https://storage.googleapis.com/amp-vs-non-amp/youtube-lazy.html + * https://autoplay-youtube-player.glitch.me/ + * + * Once built it, I also found these: + * https://github.com/ampproject/amphtml/blob/master/extensions/amp-youtube (👍👍) + * 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'; + + /** + * Lo, the youtube placeholder image! (aka the thumbnail, poster image, etc) + * + * See https://github.com/paulirish/lite-youtube-embed/blob/master/youtube-thumbnail-urls.md + * + * TODO: Do the sddefault->hqdefault fallback + * - When doing this, apply referrerpolicy (https://github.com/ampproject/amphtml/pull/3940) + * TODO: Consider using webp if supported, falling back to jpg + */ + if (!this.style.backgroundImage) { + this.posterUrl = `https://i.ytimg.com/vi/${this.videoId}/hqdefault.jpg`; + // Warm the connection for the poster image + LiteYTEmbed.addPrefetch('preload', this.posterUrl, 'image'); + + this.style.backgroundImage = `url("${this.posterUrl}")`; + } + + // 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); + } + + // On hover (or tap), warm up the TCP connections we're (likely) about to use. + this.addEventListener('pointerover', 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', e => this.addIframe()); + } + + // // TODO: Support the the user changing the [videoid] attribute + // attributeChangedCallback() { + // } + + /** + * 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; + } + + addIframe() { + const params = new URLSearchParams(this.getAttribute('params') || []); + params.append('autoplay', '1'); + + const iframeEl = document.createElement('iframe'); + iframeEl.width = 560; + iframeEl.height = 315; + // No encoding necessary as [title] is safe. https://cheatsheetseries.owasp.org/cheatsheets/Cross_Site_Scripting_Prevention_Cheat_Sheet.html#:~:text=Safe%20HTML%20Attributes%20include + iframeEl.title = this.playLabel; + iframeEl.allow = 'accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture'; + iframeEl.allowFullscreen = true; + // AFAIK, the encoding here isn't necessary for XSS, but we'll do it only because this is a URL + // https://stackoverflow.com/q/64959723/89484 + iframeEl.src = `https://www.youtube-nocookie.com/embed/${encodeURIComponent(this.videoId)}?${params.toString()}`; + this.append(iframeEl); + + this.classList.add('lyt-activated'); + + // Set focus for a11y + this.querySelector('iframe').focus(); + } +} +// Register custom element +customElements.define('lite-youtube', LiteYTEmbed); diff --git a/scripts/scripts.js b/scripts/scripts.js index 7bf57938..8fda48a9 100644 --- a/scripts/scripts.js +++ b/scripts/scripts.js @@ -11,6 +11,7 @@ import { waitForLCP, loadBlocks, loadCSS, + loadScript, getMetadata, decorateBlock, loadBlock, } from './aem.js'; @@ -113,6 +114,42 @@ function buildLiveByMetadata(main) { } } +export function getYoutubeVideoId(url) { + if (url.includes('youtube.com/watch?v=')) { + return new URL(url).searchParams.get('v'); + } + if (url.includes('youtube.com/embed/') || url.includes('youtu.be/')) { + return new URL(url).pathname.split('/').pop(); + } + return null; +} + +function decorateVideoLinks(main) { + [...main.querySelectorAll('a')] + .filter(({ href }) => !!href) + // only convert plain links + .filter((a) => a.textContent?.trim()?.toLowerCase().startsWith('http')) + // don't decorate if already in a block. unless it's `columns`. + .filter((a) => { + const block = a.closest('div.block'); + if (!block) return true; + return block.classList.contains('columns'); + }) + .forEach((link) => { + const youtubeVideoId = getYoutubeVideoId(link.href); + + if (youtubeVideoId) { + loadCSS('/blocks/embed/lite-yt-embed.css'); + loadScript('/blocks/embed/lite-yt-embed.js'); + const video = document.createElement('lite-youtube'); + video.setAttribute('videoid', youtubeVideoId); + video.setAttribute('params', 'rel=0'); + video.classList.add('youtube-video'); + link.replaceWith(video); + } + }); +} + /** * Build Floating image block * @param {Element} main The container element @@ -214,6 +251,7 @@ export function decorateMain(main) { buildAutoBlocks(main); decorateSections(main); decorateBlocks(main); + decorateVideoLinks(main); } /**