name : wp-emoji-loader.js /** * @output wp-includes/js/wp-emoji-loader.js */ /** * Emoji Settings as exported in PHP via _print_emoji_detection_script(). * @typedef WPEmojiSettings * @type {object} * @property {?object} source * @property {?string} source.concatemoji * @property {?string} source.twemoji * @property {?string} source.wpemoji * @property {?boolean} DOMReady * @property {?Function} readyCallback */ /** * Support tests. * @typedef SupportTests * @type {object} * @property {?boolean} flag * @property {?boolean} emoji */ /** * IIFE to detect emoji support and load Twemoji if needed. * * @param {Window} window * @param {Document} document * @param {WPEmojiSettings} settings */ ( function wpEmojiLoader( window, document, settings ) { if ( typeof Promise === 'undefined' ) { return; } var sessionStorageKey = 'wpEmojiSettingsSupports'; var tests = [ 'flag', 'emoji' ]; /** * Checks whether the browser supports offloading to a Worker. * * @since 6.3.0 * * @private * * @returns {boolean} */ function supportsWorkerOffloading() { return ( typeof Worker !== 'undefined' && typeof OffscreenCanvas !== 'undefined' && typeof URL !== 'undefined' && URL.createObjectURL && typeof Blob !== 'undefined' ); } /** * @typedef SessionSupportTests * @type {object} * @property {number} timestamp * @property {SupportTests} supportTests */ /** * Get support tests from session. * * @since 6.3.0 * * @private * * @returns {?SupportTests} Support tests, or null if not set or older than 1 week. */ function getSessionSupportTests() { try { /** @type {SessionSupportTests} */ var item = JSON.parse( sessionStorage.getItem( sessionStorageKey ) ); if ( typeof item === 'object' && typeof item.timestamp === 'number' && new Date().valueOf() < item.timestamp + 604800 && // Note: Number is a week in seconds. typeof item.supportTests === 'object' ) { return item.supportTests; } } catch ( e ) {} return null; } /** * Persist the supports in session storage. * * @since 6.3.0 * * @private * * @param {SupportTests} supportTests Support tests. */ function setSessionSupportTests( supportTests ) { try { /** @type {SessionSupportTests} */ var item = { supportTests: supportTests, timestamp: new Date().valueOf() }; sessionStorage.setItem( sessionStorageKey, JSON.stringify( item ) ); } catch ( e ) {} } /** * Checks if two sets of Emoji characters render the same visually. * * This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing * scope. Everything must be passed by parameters. * * @since 4.9.0 * * @private * * @param {CanvasRenderingContext2D} context 2D Context. * @param {string} set1 Set of Emoji to test. * @param {string} set2 Set of Emoji to test. * * @return {boolean} True if the two sets render the same. */ function emojiSetsRenderIdentically( context, set1, set2 ) { // Cleanup from previous test. context.clearRect( 0, 0, context.canvas.width, context.canvas.height ); context.fillText( set1, 0, 0 ); var rendered1 = new Uint32Array( context.getImageData( 0, 0, context.canvas.width, context.canvas.height ).data ); // Cleanup from previous test. context.clearRect( 0, 0, context.canvas.width, context.canvas.height ); context.fillText( set2, 0, 0 ); var rendered2 = new Uint32Array( context.getImageData( 0, 0, context.canvas.width, context.canvas.height ).data ); return rendered1.every( function ( rendered2Data, index ) { return rendered2Data === rendered2[ index ]; } ); } /** * Determines if the browser properly renders Emoji that Twemoji can supplement. * * This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing * scope. Everything must be passed by parameters. * * @since 4.2.0 * * @private * * @param {CanvasRenderingContext2D} context 2D Context. * @param {string} type Whether to test for support of "flag" or "emoji". * @param {Function} emojiSetsRenderIdentically Reference to emojiSetsRenderIdentically function, needed due to minification. * * @return {boolean} True if the browser can render emoji, false if it cannot. */ function browserSupportsEmoji( context, type, emojiSetsRenderIdentically ) { var isIdentical; switch ( type ) { case 'flag': /* * Test for Transgender flag compatibility. Added in Unicode 13. * * To test for support, we try to render it, and compare the rendering to how it would look if * the browser doesn't render it correctly (white flag emoji + transgender symbol). */ isIdentical = emojiSetsRenderIdentically( context, '\uD83C\uDFF3\uFE0F\u200D\u26A7\uFE0F', // as a zero-width joiner sequence '\uD83C\uDFF3\uFE0F\u200B\u26A7\uFE0F' // separated by a zero-width space ); if ( isIdentical ) { return false; } /* * Test for UN flag compatibility. This is the least supported of the letter locale flags, * so gives us an easy test for full support. * * To test for support, we try to render it, and compare the rendering to how it would look if * the browser doesn't render it correctly ([U] + [N]). */ isIdentical = emojiSetsRenderIdentically( context, '\uD83C\uDDFA\uD83C\uDDF3', // as the sequence of two code points '\uD83C\uDDFA\u200B\uD83C\uDDF3' // as the two code points separated by a zero-width space ); if ( isIdentical ) { return false; } /* * Test for English flag compatibility. England is a country in the United Kingdom, it * does not have a two letter locale code but rather a five letter sub-division code. * * To test for support, we try to render it, and compare the rendering to how it would look if * the browser doesn't render it correctly (black flag emoji + [G] + [B] + [E] + [N] + [G]). */ isIdentical = emojiSetsRenderIdentically( context, // as the flag sequence '\uD83C\uDFF4\uDB40\uDC67\uDB40\uDC62\uDB40\uDC65\uDB40\uDC6E\uDB40\uDC67\uDB40\uDC7F', // with each code point separated by a zero-width space '\uD83C\uDFF4\u200B\uDB40\uDC67\u200B\uDB40\uDC62\u200B\uDB40\uDC65\u200B\uDB40\uDC6E\u200B\uDB40\uDC67\u200B\uDB40\uDC7F' ); return ! isIdentical; case 'emoji': /* * Four and twenty blackbirds baked in a pie. * * To test for Emoji 15.0 support, try to render a new emoji: Blackbird. * * The Blackbird is a ZWJ sequence combining 🐦 Bird and ⬛ large black square., * * 0x1F426 (\uD83D\uDC26) == Bird * 0x200D == Zero-Width Joiner (ZWJ) that links the code points for the new emoji or * 0x200B == Zero-Width Space (ZWS) that is rendered for clients not supporting the new emoji. * 0x2B1B == Large Black Square * * When updating this test for future Emoji releases, ensure that individual emoji that make up the * sequence come from older emoji standards. */ isIdentical = emojiSetsRenderIdentically( context, '\uD83D\uDC26\u200D\u2B1B', // as the zero-width joiner sequence '\uD83D\uDC26\u200B\u2B1B' // separated by a zero-width space ); return ! isIdentical; } return false; } /** * Checks emoji support tests. * * This function may be serialized to run in a Worker. Therefore, it cannot refer to variables from the containing * scope. Everything must be passed by parameters. * * @since 6.3.0 * * @private * * @param {string[]} tests Tests. * @param {Function} browserSupportsEmoji Reference to browserSupportsEmoji function, needed due to minification. * @param {Function} emojiSetsRenderIdentically Reference to emojiSetsRenderIdentically function, needed due to minification. * * @return {SupportTests} Support tests. */ function testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically ) { var canvas; if ( typeof WorkerGlobalScope !== 'undefined' && self instanceof WorkerGlobalScope ) { canvas = new OffscreenCanvas( 300, 150 ); // Dimensions are default for HTMLCanvasElement. } else { canvas = document.createElement( 'canvas' ); } var context = canvas.getContext( '2d', { willReadFrequently: true } ); /* * Chrome on OS X added native emoji rendering in M41. Unfortunately, * it doesn't work when the font is bolder than 500 weight. So, we * check for bold rendering support to avoid invisible emoji in Chrome. */ context.textBaseline = 'top'; context.font = '600 32px Arial'; var supports = {}; tests.forEach( function ( test ) { supports[ test ] = browserSupportsEmoji( context, test, emojiSetsRenderIdentically ); } ); return supports; } /** * Adds a script to the head of the document. * * @ignore * * @since 4.2.0 * * @param {string} src The url where the script is located. * * @return {void} */ function addScript( src ) { var script = document.createElement( 'script' ); script.src = src; script.defer = true; document.head.appendChild( script ); } settings.supports = { everything: true, everythingExceptFlag: true }; // Create a promise for DOMContentLoaded since the worker logic may finish after the event has fired. var domReadyPromise = new Promise( function ( resolve ) { document.addEventListener( 'DOMContentLoaded', resolve, { once: true } ); } ); // Obtain the emoji support from the browser, asynchronously when possible. new Promise( function ( resolve ) { var supportTests = getSessionSupportTests(); if ( supportTests ) { resolve( supportTests ); return; } if ( supportsWorkerOffloading() ) { try { // Note that the functions are being passed as arguments due to minification. var workerScript = 'postMessage(' + testEmojiSupports.toString() + '(' + [ JSON.stringify( tests ), browserSupportsEmoji.toString(), emojiSetsRenderIdentically.toString() ].join( ',' ) + '));'; var blob = new Blob( [ workerScript ], { type: 'text/javascript' } ); var worker = new Worker( URL.createObjectURL( blob ), { name: 'wpTestEmojiSupports' } ); worker.onmessage = function ( event ) { supportTests = event.data; setSessionSupportTests( supportTests ); worker.terminate(); resolve( supportTests ); }; return; } catch ( e ) {} } supportTests = testEmojiSupports( tests, browserSupportsEmoji, emojiSetsRenderIdentically ); setSessionSupportTests( supportTests ); resolve( supportTests ); } ) // Once the browser emoji support has been obtained from the session, finalize the settings. .then( function ( supportTests ) { /* * Tests the browser support for flag emojis and other emojis, and adjusts the * support settings accordingly. */ for ( var test in supportTests ) { settings.supports[ test ] = supportTests[ test ]; settings.supports.everything = settings.supports.everything && settings.supports[ test ]; if ( 'flag' !== test ) { settings.supports.everythingExceptFlag = settings.supports.everythingExceptFlag && settings.supports[ test ]; } } settings.supports.everythingExceptFlag = settings.supports.everythingExceptFlag && ! settings.supports.flag; // Sets DOMReady to false and assigns a ready function to settings. settings.DOMReady = false; settings.readyCallback = function () { settings.DOMReady = true; }; } ) .then( function () { return domReadyPromise; } ) .then( function () { // When the browser can not render everything we need to load a polyfill. if ( ! settings.supports.everything ) { settings.readyCallback(); var src = settings.source || {}; if ( src.concatemoji ) { addScript( src.concatemoji ); } else if ( src.wpemoji && src.twemoji ) { addScript( src.twemoji ); addScript( src.wpemoji ); } } } ); } )( window, document, window._wpemojiSettings );