Web Accessibility - A feature you can build

Web Accessibility (a11y) A feature you can build2014 Monika Piotrowicz (@monsika)

Monika PiotrowiczFront End Web Dev Lead Shopify !

@monsika @shopify

I’m just...A regular Front End Developer... !

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So how’d I get here? A short story, starring WCAG 2.0 AA !

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Today• Introduction to accessibility • Techniques you can implement today • Introduction to screen readers & ARIA • Testing tips

Web Accessibility• “When sites are correctly designed,

developed and edited, all users can have equal access to information and functionality” - Wikipedia

• “Able to be easily obtained or used; easily understood or appreciated” - Oxford Dictionary

• Accessibility ~ Usability

• All people can use an application, and it should be easy to use for all people;

Accessibility by the #’s

rough

1 - CDC Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2011 http://1.usa.gov/M6tObC (under 65/over 65)!

2 - Range worldwide prevalence of red-green color deficiency among men, 2012 http://1.usa.gov/M6tKsz

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Group Population

Vision Problems 3-10%

Colorblindness 4-8%

Physical Functioning 8%

Cognitive Difficulty 6%

Hearing Difficulty 3-11%

Assistive Tools

• screen readers

• screen magnifiers

• keyboard-only

• braille display

• bumped font size

WCAGThe standard http://www.w3.org/TR/WCAG20/

Understanding WCAG http://www.w3.org/TR/UNDERSTANDING-WCAG20/

Techniques http://www.w3.org/TR/WCAG20-TECHS/

Quick Reference http://www.w3.org/WAI/WCAG20/quickref/

FAQ http://www.w3.org/WAI/WCAG20/wcag2faq.html

Accessibility

just a checklist

!=

Starting outEarly accessibility considerations

First Steps• clear visuals with fallbacks for imagery

• well-functioning forms

• keyboard interactions

Visual Considerations• start with a good font size & high contrast

• Contrast Checker Tool - contrast-finder.tanaguru.com

• Chrome Plugin - http://bit.ly/1ljQvFF • Accessible colour palette how-to http://bit.ly/1fnbmJp

Visual Considerations✓ start with a good font size & high contrast

• Contrast Checker Tool - contrast-finder.tanaguru.com

• Chrome Plugin - http://bit.ly/1ljQvFF • Accessible colour palette how-to http://bit.ly/1fnbmJp

• don’t rely on colour alone

• add legends and texture or symbols

Red-Green Colorblind (Deuteranopia)

Visual Considerations✓ start with a good font size & high contrast

• Contrast Checker Tool - contrast-finder.tanaguru.com • Chrome Plugin - http://bit.ly/1ljQvFF • Accessible colour palette how-to http://bit.ly/1fnbmJp

✓ don’t rely on colour alone

• add legends and texture or symbols

• all images have a meaningful alt attribute • W3C How to write Alt Text http://bit.ly/1aKwIOg

• More from A List Apart http://bit.ly/1aKwRkI

• Every form field includes a real label <label for="[INPUT ID]">

• Placeholders don’t count

• Labels can include help, required, error text

• Provide meaningful message and action on form error

WebAIM Forms http://bit.ly/1aKw2bM Harmful Placeholders http://bit.ly/1qNUTOM WebAIM Validation http://bit.ly/1aKw6bB Accessible Form Labeling http://bit.ly/1aKw83b

Forms

<label for="InputFirstName"> <span class="txt-label">First Name *</span> <span class="txt-error">Required, please provide your first name</span> </label> <input type="text" id=“InputFirstName" required />

WebAIM Forms http://bit.ly/1aKw2bM Harmful Placeholders http://bit.ly/1qNUTOM WebAIM Validation http://bit.ly/1aKw6bB Accessible Form Labeling http://bit.ly/1aKw83b

a, a:focus { outline: none; outline: 0; }

Keyboard Strategy✓ obvious focus states (keep those outlines!)

• add tabindex=0 to non-focusable, clickable elements

Keyboard Strategy✓ obvious focus states (keep those outlines!)

✓ add tabindex=0 to non-focusable, clickable elements

• add equivalents for :hover, hover() & click() ↳ :focus, focusin() & keydown()

$modalTrigger.attr('tabindex', '0'); $modalTrigger.on({ 'click': handleTrigger, 'keydown': function (evt) { var keyPressed = evt.keyCode; if (keyPressed === app.keyCodes.ENTER || keyPressed === app.keyCodes.SPACE) { handleTrigger();

Keyboard Strategy✓ obvious focus states (keep those outlines!)

✓ add tabindex=0 to non-focusable, clickable elements

✓ add equivalents for :hover, hover() & click() ↳ :focus, focusin() & keydown()

• HTML can get you there, FREE!

WebAIM http://bit.ly/M24Da2 Tabindex bit.ly/1xY7eCL Keyboard Events http://bit.ly/M241Br

Wanted: Free Events!

<span class="btn toggle-trigger" tabindex="0">Click to Toggle</span> !<a href="#" class="btn toggle-trigger">Click to Toggle</a> !<button type="button" class="toggle-trigger">Click to Toggle</button>

Use the button element http://bit.ly/1efaOO1 Links aren’t buttons http://bit.ly/1efaT4o

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• opened modal window?

onModalOpen = function($modalWrapper) { $modalWrapper.attr('tabindex', '-1').focus(); };

Focus Management• Focus follows the user…

focus()

• Focus follows the user…

• opened modal window?

• scrolled viewport?

• transitioned to new view? focus()

Focus Management

focus()

focus()

• Focus follows the user…

• opened modal window?

• scrolled viewport?

• transitioned to new view?

• closed modal window? freakOut()

Focus Management

!$modalTrigger.on('click', function(e){ var $modal, modalTrigger = e.currentTarget; ! // modal logic here ! // save trigger elem so on modalClose it gets focus $modal.data('trigger', modalTrigger); }); !handleModalClose = function() { var newFocusElem = $modal.data('trigger'); ! // focus returns to the element that triggered the modal $(newFocusElem).focus(); ! // remove the trigger, might be different next time $modal.removeData('trigger'); };

http://codepen.io/mpiotrowicz/full/Juocl/

Have an exit strategy

mousetrap

Photograph by Sheba_Also licensed under Creative Commons

boldly go...The SCREEN READER

TRY ONE!! How else can you expect to build for one?

NVDA

VoiceOver TalkBack

JAWS

How do they work?• announce generated HTML in source

order

• Use keyboard to navigate and find content

• Highly customizable

Screen reader 101!

• 97.6% of screen reader users have JS enabled! 1

1 - WebAIM Survey http://bit.ly/1nqd4fp

HTML COUNTS!• Shortcuts drill down to headings,

landmarks, lists, links, etc

• Do your main content areas have headings?

• Are they descriptive?

• Do they follow a hierarchy? (h1 >> h6)

Headings

Document Outline http://bit.ly/1ef9ScA The Section Element http://bit.ly/1ef9TNN Accessible Headings http://bit.ly/1ef9QBr Using Sections http://bit.ly/1ef9Ykx

H1 Blog H2 Recent Articles H3 Article Title H3 Article Title H3 Article Title H2 About Me H3 Contact Me H3 Footer Title

• Main way screen reader users navigate

• img with empty alt attribute alt=""

SR’s ignore...

• :before content, :after content* (sort of)

• display: none;

• visibility: hidden;

* in most cases, so assume it won’t be announced Accessible Icon Fonts http://bit.ly/1efabUP

.icon-star:before { content: “★”; }

• keep in mind for icons and icon fonts!• or just use SVG

• content “hidden” with opacity, z-index, height

• off-screen positioning (text-indent, top, left)

.sr-only,

.visuallyhidden { border: 0; clip: rect(0 0 0 0); height: 1px; margin: -1px; overflow: hidden; padding: 0; position: absolute; width: 1px; }

* as seen in HTML5 BP, Twitter Bootstrap, etc. WebAIM Invisible Content http://bit.ly/1efaij8

• CSS clipping*

SR’s won’t ignore

Beyond the basicsThere’s gotta be more to screen readers than just that, right?

• Applied directly to HTML

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• Does not affect styles or non-SR behaviour

• Roles, states & properties

• Semantic information and better interactions for screen readers

ARIA

• Part of HTML5 spec

HTML5 Spec (W3C) http://bit.ly/1aKxXx5 ARIA Spec (W3C) http://bit.ly/1aKya3f

Roles• Create new semantic meaning for

elements via “role-” attribute

• Once set, they don’t change

<nav role="navigation"> !<article role="article"> !<div role="tablist"> !<div role="combobox">

Landmark RolesDefine top-level page sections for easy navigation

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•main

•banner

•navigation

•search

•complimentary

•contentinfo

•form

Role

Landmark RolesDefine top-level page sections for easy navigation

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•main ........ <main>

•banner ........ <header>

•navigation ........ <nav>

•search ........ <form> (search form)

•complimentary ........ <aside>

•contentinfo ........ <footer>

•form

Role HTML 5

Using Landmarks http://bit.ly/1aKyuyQ WebAIM Landmarks http://bit.ly/1aKytem Support for HTML5 as landmarks http://bit.ly/LVR8YX

Include all content in a landmark

Elements using landmark roles

role="banner"

role="navigation"

role="main"

Widget RolesSemantic meaning to your custom components

• tooltip

• slider

• dialog

• tab

• progressbar

• combobox

• menu

• alert

.. and many more! http://www.w3.org/TR/wai-aria/roles#widget_roles

ul class="tab-controls"> <li> <a href="#Tab1">Panel 1</a> </li> <li> <a href="#Tab2" class="current-item">Panel 2</a> </li> <li> <a href="#Tab3">Panel 3</a> </li> </ul> <div id="TabContainer"> <div class="tab-panel" id="Tab1"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> <div class="tab-panel" id="Tab2"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> <div class="tab-panel" id="Tab3"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> </div>

???<ul class="tab-controls" role="tablist"> <li> <a href="#Tab1" class="current-item" role="tab">Panel 1</a> !<div id="tab-container"> <div class="tab-panel" id="Tab1" role="tab-panel">

http://codepen.io/mpiotrowicz/full/gocmu/

• Describe relationships between content & between user interactions

• updated via JS on UI changes

• attributes start with “aria-” prefix

States & Properties

<ul class="tab-controls"> <li> <a href="#Tab1">Panel 1</a> </li> <li> <a href="#Tab2" class="current-item">Panel 2</a> </li> <li> <a href="#Tab3">Panel 3</a> </li> </ul> <div id="TabContainer"> <div class="tab-panel" id="Tab1"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> <div class="tab-panel" id="Tab2"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> <div class="tab-panel" id="Tab3"> <div class="tab-contents"> <p>Tab Contents</p> </div> </div> </div>

<ul class="tab-controls" role="tablist"> <li> <a href="#first-tab" class="current-item" role="tab">Panel 1</a> !<div id="tab-container"> <div class="tab-panel" id="first-tab" role="tab-panel">

<ul class="tab-controls" role="tablist"> <li> <a href=“#Tab1" class="current-item" role="tab" aria-selected="true" aria-expanded="true" aria-controls="Tab1" >Panel 1</a> !<div id="tab-container"> <div class="tab-panel" id=“Tab1" aria-hidden=“false" role=“tab-panel">

http://codepen.io/mpiotrowicz/full/gocmu/

Content Relationships• Semantically link labels to content or add

them when missing • aria-labelledby

• aria-describedby

• aria-label

} text-element ID’s, comma-separated

string of label text

Content Relationships

<section aria-labelledby="HeadingAbout"> <h1 id="HeadingAbout">About Potato Chips</h1> <p>....

Make the most of landmarks http://bit.ly/M1TFSb

Content Relationships

<nav role="navigation" aria-label="Chip Section Navigation"> <ul> <li> <a href="/types">Flavors</a> </li>

<label for="InputPhoneNumber">Phone Number</label> <input aria-describedby="PhoneHelpText" id="InputPhoneNumber"> <span id="PhoneHelpText"> eg. 555-555-5555. We will use this number only in case of emergency </span>

Content Relationships

<label for="InputPhoneNumber">Phone Number</label> <input aria-describedby="PhoneHelpText" aria-required="true" id="InputPhoneNumber"> <span id="PhoneHelpText"> eg. 555-555-5555. We will use this number only in case of emergency </span>

Descriptions

<label for="InputPhoneNumber">Phone Number</label> <input aria-describedby="PhoneHelpText" aria-required="true" aria-invalid="true" id="InputPhoneNumber"> <span id="PhoneHelpText"> eg. 555-555-5555. We will use this number only in case of emergency </span>

Descriptions

<label for="InputPhoneNumber">Phone Number</label> <input aria-describedby="PhoneHelpText" aria-required="true" aria-invalid="true" id="InputPhoneNumber"> <span id="PhoneHelpText"> eg. 555-555-5555. We will use this number only in case of emergency </span>

Descriptions

aria-pressed aria-selected aria-checked aria-disabled aria-expanded

aria-controls aria-haspopup aria-valuemax aria-valuemin aria-multiselectable aria-owns aria-live

http://www.w3.org/TR/wai-aria/states_and_properties

It's just HTML!

.elem[aria-hidden = "false"] { display: block; } !.elem[aria-invalid ="true"] { background: red; } !.elem[aria-selected = "true"] { border: green; }

The more you know

Putting it all together• A11y Project Patterns http://a11yproject.com/patterns/

• Tab Example - http://codepen.io/mpiotrowicz/full/gocmu/

• Practical ARIA Examples http://bit.ly/1bhMqBg

• HTML5 & ARIA Design Patterns http://bit.ly/1bhMlNZ

• jQueryUI https://jqueryui.com/

• Angular JS & Accessibility http://bit.ly/1sPwCax

• Bootstrap Accessibility Plugin (PayPal) http://bit.ly/1bhM8dy

• Accessible Web Components http://bit.ly/1iMwBiG

Using ARIA Wisely• ARIA is a bridge, not a replacement.

• USE plain HTML if you can

• Not magic and makes no promises

• Events, focus management, keyboard support, and meaningful structure is still up to you

• Only way to know for sure... TEST

ARIA ResourcesGetting Started with ARIA

http://a11yproject.com/posts/getting-started-aria/

The WAI forward http://www.smashingmagazine.com/2014/07/09/the-wai-forward/

W3C Intro http://www.w3.org/TR/wai-aria-primer/

W3C Design Patterns http://www.w3.org/TR/wai-aria-practices/

W3C Supporting Info for developers http://www.w3.org/TR/aria-in-html/

WEBAIM Introduction http://webaim.org/techniques/aria/

Testing

Automated Tools• Accessibility Dev Tools (Chrome) http://bit.ly/1fW0W0A

• Web Dev Toolbar (Chrome & FF) http://bit.ly/1dA2JmY

• WebAIM WAVE (FF) http://wave.webaim.org/toolbar/

• Quail Project quailjs.org

• TenonIO - http://tenon.io/

Manual Testing• disable all images

• test with just a keyboard

• load it in a screen reader

• load it in another screen reader

Testing for Web Accessibility in 60 seconds http://bit.ly/1tSju4E 10 Tips anyone can use http://bit.ly/1efaA9N 6 Tests anyone can do http://bit.ly/1efaC1c

Does your page make sense?

Is it usable ?

Unsolicited Advice• Start small, there’s still a big impact

• Prioritize areas/pages

• main navigation? • contact us form? • homepage?

• Document as you go

Final Thoughts

What I’ve learned• Bake it in, don’t tack it on

• Awesome and helpful community

• You may find it hard to stop

Behind all these checklists, rules, and regulations, there are people just trying

to use your site.

So make it useable, for everybody.

Thanks!!Questions? @monsika

More Resources

General

Accessibility Evaluation Quick Reference http://bit.ly/M6tgCF

The Accessibility Tree - http://bit.ly/1kzPmO6

Mozilla Dev Network ARIA http://mzl.la/M6u9ez How Not To Misuse ARIA States, Properties and Roles http://bit.ly/1vzXfI1

Screen Readers WebAIM Screen Reader Testing http://bit.ly/M6sLIH Videos of Screen Readers In Use http://bit.ly/M6sR39 How browsers interact with screen readers http://bit.ly/M6sUfi

NVDA resources

WebAIM NVDA http://bit.ly/M6sZj5 WebAIM NVDA Shortcuts http://bit.ly/M6t0n2

Using NVDA and FF to test pages http://bit.ly/M6t6Lu Installing NVDA in a VM http://bit.ly/M6t8D4

VoiceOver resources

WebAIM VoiceOver http://bit.ly/M6tbyS Apple VoiceOver User Guide http://bit.ly/M6tolE Apple Developer Accessibility Guide http://bit.ly/M6ttpe

JAWS resources

WebAIM JAWS http://bit.ly/M6tw4D WebAIM JAWS Shortcuts http://bit.ly/M6sBRM

Community & Blogs#a11y @webaim

@a11yproject

@paciellogroup

!Weekly Mailer - http://bit.ly/1zO7aIC

www.a11yproject.com www.webaim.org www.webaxe.org !an a11y Meetup near you! http://bit.ly/1bhN3dW