test.html

<!DOCTYPE html>
<html lang="en">
<head>

<meta charset="utf-8" />
<link rel="icon" href="assets/favicon.png" />
<title>Test drive ▲ Prism</title>
<link rel="stylesheet" href="assets/style.css" />
<link rel="stylesheet" href="themes/prism.css" data-noprefix />
<style>
#theme {
	margin-right: -9em;
}

textarea {
	width: 100%;
	height: 10em;
	padding: 1em;
	box-sizing: border-box;
	margin: .5em 0;
	background: #f5f2f0;
	color: black;
	text-shadow: 0 1px white;
	tab-size: 4;
	font: 100% Consolas, Monaco, monospace;
	white-space: pre;
	word-wrap: normal;
}

#language {
	column-count: 4;
}

	#language label {
		display: block;
		padding: .2em;
	}

	#language label[data-id="javascript"] {
		border-bottom: 1px solid #aaa;
		padding-bottom: 1em;
		margin-bottom: 1em;
	}

	#language input {
		margin-right: 1em;
	}

	#language strong {
		display: block;
		column-span: all;
	}


pre.show-tokens {
	line-height: calc(1.5em + 12px);
}

.show-tokens .token:not(:first-child) {
	margin-left: 1px;
}

.show-tokens .token:empty {
	background: red;
}
.show-tokens .token:empty::before {
	color: white;
	content: 'empty';
	font-style: italic;
	text-shadow: black 0 0 .3em;
}

.show-tokens .token {
	border: 1px solid;
	padding: 6px 1px;
}
.show-tokens .token > .token {
	padding: 4px 1px;
}
.show-tokens .token > .token > .token {
	padding: 2px 1px;
}
.show-tokens .token > .token > .token > .token {
	padding: 0 1px;
}
.show-tokens .token > .token > .token > .token > .token {
	border: none;
	border-left: 1px solid;
	border-right: 1px solid;
	padding: 0;
	margin: 0 1px;
}

#options {
	position: relative;
}

.link-wrapper {
	position: absolute;
	top: 0;
	right: 0;
	background-color: white;
}
.link-wrapper .hidden-wrapper {
	display: none;
}

.link-wrapper:hover {
	top: -.5em;
	right: -1em;
	width: 300px;
	padding: .5em 1em;
	outline: 1px solid #888;
}
.link-wrapper:hover .hidden-wrapper {
	display: block;
}

.link-wrapper input {
	width: 100%;
	box-sizing: border-box;
}

.link-wrapper button {
	border: none;
	background: none;
	font: inherit;
	text-decoration: underline;
	cursor: pointer;
}

</style>
<script src="assets/vendor/prefixfree.min.js"></script>

<script>var _gaq = [['_setAccount', 'UA-33746269-1'], ['_trackPageview']];</script>
<script src="https://www.google-analytics.com/ga.js" async></script>
</head>
<body>

<header>
	<div class="intro" data-src="assets/templates/header-main.html" data-type="text/html"></div>

	<h2>Test drive</h2>
	<p>Take Prism for a spin!</p>
</header>

<section>
	<form>
		<p>
			<textarea>&lt;p class="hey">Type some code here&lt;/p></textarea>
		</p>

		<p>Result:</p>
		<pre><code></code></pre>

		<div id="options" style="margin: 1em 0">
			<label><input type="checkbox" id="option-show-tokens"> Show tokens</label>
			<div class="link-wrapper">
				<a id="share-link" href="" style="float: right;">Share</a>
				<div class="hidden-wrapper">
					<input id="share-link-input" type="text" readonly onClick="this.select();"/>
					<button type="button" id="copy-share-link" onclick="copyShare();">Copy to clipboard</button>
				</div>
			</div>
		</div>
		<p id="language">
			<strong>Language:</strong>
		</p>
	</form>
</section>

<footer data-src="assets/templates/footer.html" data-type="text/html"></footer>

<script src="assets/vendor/utopia.js"></script>
<script src="components/prism-core.js"></script>
<script src="components.js"></script>
<script src="assets/code.js"></script>
<script src="assets/vendor/promise.js"></script>

<script>
(function() {
/** @type {HTMLFormElement} */
var form = $('form');
/** @type {HTMLElement} */
var code = $('code', form);
var languages = components.languages;

function highlightCode() {
	var newCode = document.createElement('code');
	newCode.textContent = code.textContent;
	newCode.className = code.className;

	Prism.highlightElement(newCode);

	code.parentElement.replaceChild(newCode, code);
	code = newCode;
};

function getHashParams() {
	return parseUrlParams((location.hash || '').substr(1));
}
function setHashParams(params) {
	location.hash = stringifyUrlParams(params);
}
function updateHashLanguage(lang) {
	var params = getHashParams();
	params.language = lang;
	setHashParams(params);
}
function getHashLanguage() {
	return getHashParams().language;
}
function getRadio(lang) {
	return $('input[name=language][value="' + lang + '"]');
}

function copyShare() {
	const link = $('#share-link').href;
	try {
		navigator.clipboard.writeText(link).then(function () {
			$('#copy-share-link').textContent = 'Copied!';
		}, function () {
			$('#copy-share-link').textContent = 'Failed to copy!';
		});
	} catch (e) {
		$('#copy-share-link').textContent = 'Failed to copy!';
	}
	setTimeout(function () {
		$('#copy-share-link').textContent = 'Copy to clipboard';
	}, 5000);
}
window.copyShare = copyShare;

window.onhashchange = function () {
	var input = getRadio(getHashLanguage());

	if (input && !input.checked) {
		input.checked = true;
		input.onclick();
	}
}


for (var id in languages) {
	if (id == 'meta') {
		continue;
	}

	var name = languages[id].title || languages[id];

	$u.element.create('label', {
		attributes: {
			'data-id': id
		},
		contents: [
			{
				tag: 'input',
				properties: {
					type: 'radio',
					name: 'language',
					value: id,
					onclick: function () {
						var lang = this.value;
						code.className = 'language-' + lang;
						code.textContent = code.textContent;
						updateHashLanguage(lang);
						updateShareLink();

						// loadLanguage() returns a promise, so we use highlightCode()
						// as resolve callback. The promise will be immediately
						// resolved if there is nothing to load.
						loadLanguage(lang).then(highlightCode);
					}
				}
			}, name
		],
		inside: '#language'
	});
}


/**
 * Loads a language, including all dependencies
 *
 * @param {string} lang the language to load
 * @type {Promise} the promise which resolves as soon as everything is loaded
 */
function loadLanguage (lang)
{
	// at first we need to fetch all dependencies for the main language
	// Note: we need to do this, even if the main language already is loaded (just to be sure..)
	//
	// We load an array of all dependencies and call recursively this function on each entry
	//
	// dependencies is now an (possibly empty) array of loading-promises
	var dependencies = getDependenciesOfLanguage(lang).map(loadLanguage);

	// We create a promise, which will resolve, as soon as all dependencies are loaded.
	// They need to be fully loaded because the main language may extend them.
	return Promise.all(dependencies)
		.then(function () {

			// If the main language itself isn't already loaded, load it now
			// and return the newly created promise (we chain the promises).
			// If the language is already loaded, just do nothing - the next .then()
			// will immediately be called
			if (!Prism.languages[lang]) {
				return new Promise(function (resolve) {
					$u.script('components/prism-' + lang + '.js', resolve);
				});
			}
		});
}


/**
 * Returns all dependencies (as identifiers) of a specific language
 *
 * @param {string} lang
 * @returns {Array.<string>} the list of dependencies. Empty if the language has none.
 */
function getDependenciesOfLanguage (lang)
{
	if (!components.languages[lang] || !components.languages[lang].require)
	{
		return [];
	}

	return ($u.type(components.languages[lang].require) === "array")
		? components.languages[lang].require
		: [components.languages[lang].require];
}


var radios = $$('input[name=language]');
var selectedRadio = radios[0];

var lastLanguageRadio = getRadio(getHashLanguage());
if (lastLanguageRadio) {
	selectedRadio = lastLanguageRadio;
}

selectedRadio.checked = true;
selectedRadio.onclick();

var textarea = $('textarea', form);

try {
	var hashText = getHashParams().text;
	if (hashText) {
		textarea.value = hashText;
	} else {
		var lastCode = sessionStorage.getItem('test-code');
		if (lastCode) {
			textarea.value = lastCode;
		}
	}
} catch (e) {
	// ignore sessionStorage errors
}

textarea.oninput = function() {
	var codeText = this.value || '';
	code.textContent = codeText;
	highlightCode();

	updateShareLink();

	try {
		sessionStorage.setItem('test-code', codeText);
	} catch (error) {
		// ignore sessionStorage errors
	}
}
textarea.oninput();

$('#option-show-tokens').onchange = function () {
	var cls = 'show-tokens';
	if (this.checked) {
		$('pre').classList.add(cls);
	} else {
		$('pre').classList.remove(cls);
	}
};
$('#option-show-tokens').onchange();

function updateShareLink() {
	var params = {
		language: /\blang(?:uage)?-([\w-]+)\b/i.exec(code.className)[1],
		text: code.textContent,
	};

	$('#share-link').href = '#' + stringifyUrlParams(params);
	$('#share-link-input').value = $('#share-link').href;
}


/**
 * @param {Record<string, string | number | boolean>} params
 * @returns {string}
 */
function stringifyUrlParams(params) {
	var parts = [];
	for (var name in params) {
		if (params.hasOwnProperty(name)) {
			var value = params[name];
			if (typeof value === 'boolean') {
				if (value) {
					parts.push(name);
				}
			} else {
				parts.push(name + '=' + encodeURIComponent(value));
			}
		}
	}
	return parts.join('&');
}
/**
 * @param {string} str
 * @returns {Record<string, string | boolean>}
 */
function parseUrlParams(str) {
	/** @type {Record<string, string | boolean>} */
	var params = {};
	str.split(/&/g).filter(Boolean).forEach(function (part) {
		var parts = part.split(/=/);
		var name = parts[0];
		if (parts.length === 1) {
			params[name] = true;
		} else {
			params[name] = decodeURIComponent(parts[1]);
		}
	});
	return params;
}

})();
</script>

</body>
</html>