FAQ using ARIA attributes to meet WCAG 2 level AA

In this example below you will see how to do a FAQ using ARIA attributes to meet WCAG 2 level AA with some HTML / CSS and Javascript

Semantically correct FAQ with animated show-hide accordian style. Vanilla JavaScript toggles ARIA attributes which are animated via CSS.

Thumbnail
This awesome code was written by 2kool2, you can see more from this user in the personal repository.
You can find the original code on Codepen.io
Copyright 2kool2 ©
  • HTML
  • CSS
  • JavaScript
<!DOCTYPE html>
<html lang="en" >

<head>
  <meta charset="UTF-8">
  <title>FAQ using ARIA attributes to meet WCAG 2 level AA</title>
  
  
  <link rel='stylesheet prefetch' href='css/kxqoaa.css'>

      <link rel="stylesheet" href="css/style.css">

  
</head>

<body>

  <h1>FAQ using <abbr title="Accessible Rich Internet Applications">ARIA</abbr> roles to meet <abbr title="Web Content Accessibility Guidelines">WCAG</abbr> 2 level AA</h1>

<dl class="dl-faq pab_container">

  <dt data-pab=faq_1><span>Is the content fully hidden?</span></dt>

  <dd id=faq_1>
    <div>
      <p>Yes.</p>
      <p>This content is hidden both visually and aurally, and doesn't appear in the keychain until the button is activated (expanded = true).</p>
    </div>
  </dd>


  <!-- adding data-pab-expand will force section open by default -->
  <dt data-pab=faq_2  data-pab-expand><span>May an answer be displayed by default?</span></dt>

  <dd id=faq_2>
    <div>
      <p>Apparently yes.</p>
      <p>This content is available by default until the button deactivates it (expanded = false) which removes it visually, aurally and from the keychain.</p>
      <p>Add the attribute <code>data-pab-expand</code> to the <code>dt</code> to open it by default.</p>
    </div>
  </dd>


  <dt data-pab=faq_3><span>Can an answer be opened by <abbr title="Universal Resource Location">URL</abbr> reference?</span></dt>

  <dd id=faq_3>
    <div>
      <p>Yes.</p>
      <p>Any question may be expanded on page load by referencing its <code>id</code> in the URL.</p>
      <p>For example this content could be automatically opened by adding "#faq_3" to the URL in the address bar like so:<br><a target=_blank title="[new window]" href="https://codepen.io/2kool2/pen/ZOkojB#faq_3">https://codepen.io/2kool2/pen/ZOkojB#faq_3</a></p>
      <p>The focus caret is moved to the activation button when referenced in this manner.</p>
    </div>
  </dd>

  <dt id=q_4 data-pab=faq_4><span>Can an anchor scroll to a question and then open the answer?</span></dt>

  <dd id=faq_4>
    <div>
      <p>Yes, though it only opens on first click. After which it simply scrolls the question to the top of the viewport.</p>
      <p>Add an unique <code>id</code> value to the question <code>dt</code> then reference the <code>id</code> in the anchors <code>href</code>.</p>
    </div>
  </dd>

  <dt data-pab=faq_5><span>Will it work with the font size scaled-up 200%?</span></dt>

  <dd id=faq_5>
    <div>
      <p>Yes.</p>
      <p>The height of a hidden block is calculated when the activaton button is pressed. It's also recalculated when the browser window is resized.</p>
      <p>In fact this module should easily scale to 300%, limited only by the display width and word length.</p>
    </div>
  </dd>

</dl>

<p>Can an anchor <a href="#q_4">open an answer</a> from just an id reference?</p>

<h2>How it works</h2>

<p>Takes a <code>dl</code> list and wraps each of its <code>dt</code> content with a <code>button</code>. The <code>dt</code> is targeted by the <code>data-pab</code> attribute which has the value of the <code>id</code> of the <code>dd</code> to show or hide.</p>

<p>Adding the attribute <code>data-pab-expand</code> to a <code>dt</code> will make a <code>dd</code> open by default.</p>

<p>If a <code>dd</code> <code>id</code> value is referenced as a fragment identifier in the <abbr title="Uniform Reference Locator">URL</abbr>, then it is also opened by default.</p>

<p>The code is very semantically written but has one caveat. It only allows a single <code>dd</code> per <code>dt</code> which is fine for an FAQ (but not so for a dictionary).</p>

<p>Note to self: Don't use "Lorem Ipsum" as place-holder text when sending for screen-reader testing. I nearly cried when I heard the gibberish spoken by Jaws today. Marking the block with a <code>lang="la"</code> may be technically correct but hardly aids comprehension.</p>

<p>GitHub repo: <a target=_blank title="[new window]" href="https://github.com/2kool2/accessible-faq">accessible-faq</a></p>

<p class=smaller><a target=_blank title="[new window]" href="https://codepen.io/2kool2/pens/public/?grid_type=list#">Pens by Mike Foskett</a> &mdash; <a target=_blank title="[new window]" href="https://websemantics.uk/">webSemantics</a></p>


<svg style="display:none">
		<defs>

			<symbol viewBox="0 0 38 38" id="icon-plus">
				<path class="icon-plus-v" d="M10.5 19l17 0"></path>
				<path class="icon-plus-h" d="M19 10.5l0 17"></path>
			</symbol>

			<symbol viewBox="0 0 38 38" id="icon-minus">
				<path class="icon-plus-v" d="M10.5 19l17 0"></path>
			</symbol>
			
			<!-- vert and hori combined make up the plus icon and allow for animation -->
			<symbol viewBox="0 0 38 38" id="icon-vert">
				<path d="M19 10.5l0 17"></path>
			</symbol>
			<symbol viewBox="0 0 38 38" id="icon-hori">
				<path d="M10.5 19l17 0"></path>
			</symbol>

		</defs>
	</svg>
  
  

    <script  src="js/index.js"></script>




</body>

</html>

/*Downloaded from https://www.codeseek.co/2kool2/faq-using-aria-attributes-to-meet-wcag-2-level-aa-ZOkojB */
body{
  padding: 0;
  font-weight:100;
  scroll-behavior: smooth;
}


/* FAQ container */

.dl-faq {
  position: relative;
  max-width: 36rem;
  margin: 2rem auto 3rem;
}

.dl-faq > dt {
  font-size: 1.2rem;
  font-weight: 100;
  padding: 1rem;

  /* Fix for IE9 & 10 */
  border-top: 1px solid rgba(255,255,255,.2);
}

dt > button {
  color: inherit;
  background-color: inherit;
}
.dl-faq > dt:first-child .pab-btn,
.dl-faq > dt:first-child {
  border-top: 0;
}

.dl-faq.pab_container > dt {
  /* added via JS */
  padding: 0;
}

.dl-faq > dd {
  margin: 0 auto;
  padding: 0 1.5em;
  font-weight:100;
}

.dl-faq > dd > div {
  padding: 0 0 2rem;
}

.dl-faq div > p {
  margin: 0 0 1rem;
}

.dl-faq div >:last-child {
  margin: 0;
}


/* The acivating buttons added via JS */

.pab-btn {
  position: relative;
  cursor: pointer;
  transition: color .3s ease-in;

  /* Using absolute positioning for SVG so reserve some space */
  padding: 1rem 2.5rem 1rem .5rem;
  border: 0 solid transparent;
  border-top: 1px solid rgba(0,0,0,.75);

  /* inherit doesn't work in IE */
  font-size: inherit;
  text-align: left;
  width: 100%;
}

.pab-btn:hover,
.pab-btn:focus,
.pab-btn:active {
  color:#fff;
  background-color: rgba(0,0,0,.25);
}

.pab-btn:focus {
  outline: 0 solid;
}

.pab-btn::-moz-focus-inner {
  border: 0;
  padding: 0;
  margin-top: -2px;
  margin-bottom: -2px;
}


/* Underline text on button hover (Tesco requirement) */

.pab-btn > span {
  position: relative;
  /* Removes button drepression in IE */
  pointer-events: none;
  /* Required by Safari */
  border-bottom: 1px solid transparent;
  transition: border-color .3s;
}

.pab-btn:hover > span,
.pab-btn:focus > span {
  border-bottom-color: rgba(255,255,255,.5);
}

.pab-btn:active > span {
  border-bottom-color: transparent;
}


/* SVG plus */

.pab-svg-plus {
  /* Tesco requirement
  border: 2px solid currentColor; */
  border-radius: 100%;
  display: block;
  position: absolute;
  top: calc(50% - .75em);
  right: 4px;
  width: 1.5em;
  height: 1.5em;
  margin: 0;
  pointer-events: none;
  stroke-width: 4;
  stroke-linecap: square;
  stroke: currentColor;
  -webkit-transition: transform .7s ease-out, box-shadow .3s ease-out;
  transition: transform .7s ease-out, box-shadow .3s ease-out;
}

.pab-btn:hover .pab-svg-plus,
.pab-btn:focus .pab-svg-plus {
  /* Same colour as text but with .4 alpha */
  /* Tesco requirement
  box-shadow: 0 0 0 4px rgba(0, 83, 159, 0.4);*/
}

.pab-btn:active .pab-svg-plus {
  /* Tesco requirement
  box-shadow: 0 0 0 4px rgba(0, 83, 159, 0);*/
}

[aria-expanded="true"] > .pab-svg-plus {
  transform: rotateZ(360deg);
}

.use-plus {
  /* used to animate plus into minus */
  -webkit-transition: stroke .5s ease-out, opacity .7s ease-out;
  transition: stroke .5s ease-out, opacity .7s ease-out;
}

[aria-expanded=true] .use-plus {
  opacity: 0;
}

.isSafari .pab-btn .pab-svg-plus {
  box-shadow: none;
}


/* Open / close animation - The inaccurate CSS max-height is resolved via JS adding an inline style */

[data-pab] + [aria-hidden] {
  overflow: hidden;
  opacity: 1;
  max-height: 50rem;
  visibility: visible;
  transition: visibility 0s ease 0s, max-height .65s ease-out 0s, opacity .65s ease-in 0s;
}

[data-pab] + [aria-hidden="true"] {
  max-height: 0;
  opacity: 0;
  visibility: hidden;
  transition-delay: .66s, 0s, 0s;
}


/* Overide the max-height set as an inline style by the JS */

[data-pab] + [style][aria-hidden="true"] {
  max-height: 0 !important;
}

/*Downloaded from https://www.codeseek.co/2kool2/faq-using-aria-attributes-to-meet-wcag-2-level-aa-ZOkojB */

// https://john-dugan.com/javascript-debounce/
// https://codepen.io/johndugan/pen/BNwBWL?editors=001
var debounce = function(func, wait, immediate) {

  "use strict";

  var timeout;
  return function() {
    var context = this;
    var args = arguments;
    var later = function() {
      timeout = null;
      if ( !immediate ) {
        func.apply(context, args);
      }
    };
    var callNow = immediate && !timeout;
    clearTimeout(timeout);
    timeout = setTimeout(later, wait || 200);
    if ( callNow ) {
      func.apply(context, args);
    }
  };
};



// peek-a-boo.7.3.js - Mike Foskett - https://websemantics.uk/articles/peek-a-boo-v7/

// Show - hide a block - adapted for FAQ
// Requires:
//    setAttribute / getAttribute (IE9+)
//    classList (IE10+)  - disabled
//    addEventListener (IE9+)
//    requestAnimationFrame (IE10+) - replace with requestAF() for IE9
//    querySelectorAll
//    preventDefault
//    debounce()

	

// FAQ version:
// v7.4 Added: open an question from an internal anchor
// v7.3 Expanded when URI fragment matches the target ID
// v7.2 HTML button reinstated, js adjusted.
//			Initial open/close state reworked


var Pab = (function (window, document, debounce) {
	
	// Terminology used:
	// toggle - The dynamically added button used to toggle the hidden content
	// target - The object which contains the hidden content
	// toggleParent - The object which will, or does, contain the toggle button

  "use strict";

  var dataAttr = "data-pab";
  var attrName = dataAttr.replace("data-", "") + "_";
  var btnClass = dataAttr.replace("data-", "") + "-btn";
	var dataExpandAttr = dataAttr + "-expand";
  var internalId = 1;


  function $ (selector) {
    return Array.prototype.slice.call(document.querySelectorAll(selector));
  }


  function _isExpanded (obj) { // or not aria-hidden
    return obj && (obj.getAttribute("aria-expanded") === "true" || obj.getAttribute("aria-hidden") === "false");
  }


	// This function is globally reusable. Perhaps externalise for reuse?  
	// Get height of an element object
  // Assumes it is hidden by max-height: 0 in the CSS
	var _getHiddenObjectHeight = function (obj) {
    obj.setAttribute("style", "max-height: none");
		var height = obj.scrollHeight;
    obj.removeAttribute("style");
		return height;
	};

/* Not enough support to be truly useful.
   Under most circumstance aria-expanded is sufficient.
  var _setToggleSvgTitle = function(toggle) {
    var title = toggle.getElementsByTagName("title");
    if (title && title[0]) {
      title[0].innerHTML = _isExpanded(toggle) ? "Hide" : "Show";
    }
  };
*/

  var _openCloseToggleTarget = function (toggle, target, isExpanded) {
    toggle.setAttribute("aria-expanded", !isExpanded);
    _setToggleMaxHeight(target);
    window.requestAnimationFrame(function(){
      target.setAttribute("aria-hidden", isExpanded);
    });
    // _setToggleSvgTitle(toggle); - not enough support to be useful
  };


/* // deprecated to support IE 9 FAQ
  var _toggleParentClass = function (event) {
    var cls = attrName + "btn_";
    switch (event.type) {
      case "focus" :
        //event.target.parentNode.classList.add(cls + "focused");
        event.target.parentNode.className += " " + cls + "focused";
        break;
      case "blur" :
        event.target.parentNode.classList.remove(cls + "focused");
        break;
      case "mouseover" :
        event.target.parentNode.classList.add(cls + "hovered");
        break;
      case "mouseout" :
        event.target.parentNode.classList.remove(cls + "hovered");
        break;
    }
  };
*/


  var _setToggleMaxHeight = function (target) {
    if (_isExpanded(target)) {
      // max-height overidden by CSS !important
      // target.style.maxHeight = 0;
    } else {
      target.style.maxHeight = _getHiddenObjectHeight(target) + "px";
    }
  };

  var _toggleClicked = function (event) {

    var toggle = event.target;
    var target;
    var isExpanded;

    if (toggle) {

			// To prevent children bubbling up to parent causing more than one click event
			event.stopPropagation();

      target = document.getElementById(toggle.getAttribute("aria-controls"));
      if (target) {
        isExpanded = _isExpanded(toggle);
        _openCloseToggleTarget(toggle, target, isExpanded);
      }
    }
  };


  var _addToggleListeners = function (toggle) {
    // Simpler to mangage here rather than in a global handler (consider hover and blur)

    // Parent of toggle and target - Deprecated to support IE 9
    //toggle.addEventListener("focus", _toggleParentClass, false);
    //toggle.addEventListener("blur", _toggleParentClass, false);
    //toggle.addEventListener("mouseout", _toggleParentClass, false);
    //toggle.addEventListener("mouseover", _toggleParentClass, false);

    toggle.addEventListener("click", _toggleClicked, false);

  };


  var _setUpToggle = function (toggle) {

		// Create a html button, add content from parent, replace original parent content.
		var btn = document.createElement("button");
		
		btn.className = btnClass;
		btn.innerHTML = toggle.innerHTML;
		btn.setAttribute("aria-expanded", false);
		btn.setAttribute("id", attrName + internalId++);
		btn.setAttribute("aria-controls", toggle.getAttribute(dataAttr));

		toggle.innerHTML = "";
		toggle.appendChild(btn);
		
		return btn;
	};


	// Prestating the container class in the HTML allows the CSS to render before JS kicks in.
	// Add container class to parent if not prestated
  var _setUpToggleParent = function (toggle) {
    var parent = toggle.parentElement;
    if (parent && !parent.className.match(attrName + "container")) {
      //parent.classList.add(attrName + "container");
      parent.className += " " + attrName + "container";
    }
  };


  var _addToggleSVG = function (toggle) {
    var clone = toggle.cloneNode(true);
    if (!clone.innerHTML.match("svg")) {

			// HTML SVG definition allows more control
      clone.innerHTML += "<svg role=presentational focusable=false class=" + dataAttr.replace("data-", "") + "-svg-plus><use class=\"use-plus\" xlink:href=\"#icon-vert\" /><use xlink:href=\"#icon-hori\"/></svg>";
      //requestAnimationFrame(function () {
        toggle.parentElement.replaceChild(clone, toggle);
      //});
    }
    return clone;
  };


  var _setUpTargetAria = function (toggle, target) {
    target.setAttribute("aria-hidden", !_isExpanded(toggle));
    target.setAttribute("aria-labelledby", toggle.id);
  };


  var _resetAllTargetsMaxHeight = function () {
    var toggles = document.querySelectorAll("[" + dataAttr + "]");
    var i = toggles.length;
    var target;
    while (i--) {
      target = document.getElementById(toggles[i].getAttribute(dataAttr));
      if (target) {
        target.style.maxHeight = _getHiddenObjectHeight(target) + "px";
      }
    }
  };


	var isMustardCut = function () {
		return (document.querySelectorAll && document.addEventListener);
	};


	var _openIfRequired = function (toggle, target) {
		
		var fragmentId = window.location.hash.replace("#", "");
		
		// Expand by default "data-pab-expand" small delay applied
		if (toggle.parentElement.hasAttribute(dataExpandAttr)) {
			setTimeout(function () {
				_openCloseToggleTarget(toggle, target, _isExpanded(toggle));
			}, 500);
		}
    

		// Check url fragment and if target ID matches, open it
		if (target.id === fragmentId) {
			setTimeout(function () {
				_openCloseToggleTarget(toggle, target, false);
				toggle.focus();
			}, 500);
		}

	};


	var addSingleToggleTarget = function (toggleParent) {

		var targetId = toggleParent.getAttribute(dataAttr);
		var target = document.getElementById(targetId);
		var toggle;

		if (target && isMustardCut) {
			toggle = _setUpToggle(toggleParent);
			_setUpToggleParent(toggleParent);
			toggle = _addToggleSVG(toggle);
			_setUpTargetAria(toggle, target);
			_addToggleListeners(toggle);
			_openIfRequired(toggle, target);
		}
	};
  
  var hashChanged = function (e) {
    var fragmentId = window.location.hash.replace("#", "");
    var toggle = document.querySelector("#" + fragmentId + " > ." + btnClass);
    var target = document.getElementById(toggle.getAttribute("aria-controls"));
    if (!toggle || !target) {return false;}

    toggle.focus();
    toggle.scrollIntoView({behavior: "smooth", block: "start", inline: "nearest"});

    _openCloseToggleTarget(toggle, target, false);
  };


  var addToggles = function () {

		// Iterate over all toggles (elements with the "data-pab" attribute)
		var togglesMap = $("[" + dataAttr + "]").reduce(function (temp, toggleParent) {
			addSingleToggleTarget(toggleParent);
			return true;
		}, {});

    return true;
  };


	if (isMustardCut) {
		window.addEventListener("load", addToggles, false);

		// Recalculate all target max-heights after (debounced) window is resized.
		window.addEventListener("resize", debounce(_resetAllTargetsMaxHeight, 500), false);
    
    // On fragment change
		window.addEventListener("hashchange", hashChanged, false);
	}


  return {
    // Exposes an addition function to the global scope allowing toggle & target to be added dynamically.
		add: addSingleToggleTarget
  };


}(window, document, debounce));

// To add dynamically created toggles:
// Pab.add(toggle-object); // Add individual toggle & target

Comments