From 1ef1a186528d5b2b45c52d415b88a48e1a3dee85 Mon Sep 17 00:00:00 2001 From: Christian Taylor Date: Sun, 25 Aug 2024 16:10:36 -0500 Subject: [PATCH] Add video walkthrough to Usage docs --- docs/css/lite-yt-embed.css | 97 +++++++++++++++ docs/eleventy.config.js | 2 +- docs/js/lite-yt-embed.js | 238 +++++++++++++++++++++++++++++++++++++ docs/reference.njk | 3 + docs/reference/usage.md | 8 ++ package-lock.json | 12 +- package.json | 1 + 7 files changed, 358 insertions(+), 3 deletions(-) create mode 100644 docs/css/lite-yt-embed.css create mode 100644 docs/js/lite-yt-embed.js diff --git a/docs/css/lite-yt-embed.css b/docs/css/lite-yt-embed.css new file mode 100644 index 0000000..6f3d3e5 --- /dev/null +++ b/docs/css/lite-yt-embed.css @@ -0,0 +1,97 @@ +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: attr(data-title); + display: block; + position: absolute; + top: 0; + /* Pixel-perfect port of YT's gradient PNG, using https://github.com/bluesmoon/pngtocss plus optimizations */ + background-image: linear-gradient(180deg, rgb(0 0 0 / 67%) 0%, rgb(0 0 0 / 54%) 14%, rgb(0 0 0 / 15%) 54%, rgb(0 0 0 / 5%) 72%, rgb(0 0 0 / 0%) 94%); + height: 99px; + width: 100%; + font-family: "YouTube Noto", Roboto, Arial, Helvetica, sans-serif; + color: hsl(0deg 0% 93.33%); + text-shadow: 0 0 2px rgba(0, 0, 0, .5); + font-size: 18px; + padding: 25px 20px; + overflow: hidden; + white-space: nowrap; + text-overflow: ellipsis; + box-sizing: border-box; +} + +lite-youtube:hover::before { + color: white; +} + +/* 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 { + display: block; + /* Make the button element cover the whole area for a large hover/click target… */ + width: 100%; + height: 100%; + /* …but visually it's still the same size */ + background: no-repeat center/68px 48px; + /* YT's actual play button svg */ + background-image: url('data:image/svg+xml;utf8,'); + position: absolute; + cursor: pointer; + z-index: 1; + filter: grayscale(100%); + transition: filter .1s cubic-bezier(0, 0, 0.2, 1); + border: 0; +} + +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/docs/eleventy.config.js b/docs/eleventy.config.js index c7ab6bd..c7cfe8f 100644 --- a/docs/eleventy.config.js +++ b/docs/eleventy.config.js @@ -74,7 +74,7 @@ module.exports = function (eleventyConfig) { eleventyConfig.setLibrary('md', markdownLibrary) eleventyConfig.setServerOptions({ - watch: ['_sites/**/*.js'], + watch: ['_site/**/*.js'], }) return { diff --git a/docs/js/lite-yt-embed.js b/docs/js/lite-yt-embed.js new file mode 100644 index 0000000..3891c80 --- /dev/null +++ b/docs/js/lite-yt-embed.js @@ -0,0 +1,238 @@ +/** + * 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'; + + 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