Website and Web Application Accessibility

(Speed run!!!!)

Some notes before we start

  • We wrote this for the web as a platform
  • Some of this may not apply to native apps
    • We know so very little about native apps
    • However, we assume that a solid chunk of this stuff will also apply to native apps
    • Please speak up!
    • Some of this content will be very web-specific but we will skip a lot of it in the interest of SPEED RUN

Why?

  • It's the law (for web at least)
    • WCAG 2.0 applies to just web
    • WCAG 2.1 (not covered in the presentation) applies to software too
  • Better UX
    • Accessibility IS Usability
  • Everyone deserves it

Is this your website/application?

How do I start?

  • It can be less difficult than you think
    • But can also be very complicated
  • Being wrong
    • Prepare to be wrong
    • Prepare for others to be wrong
    • Prepare for this presentation to be wrong
  • It's a process
  • You will never be finished
  • It's okay to start small
    • It's better than not starting at all

@thebillygregory

A

  • Define language
  • Text alternatives for all media
  • Logical structure in a meaningful order
  • Go beyond colour
  • Keyboard navigable, controllable
  • Limit flashes
  • Skip links
  • Link purpose
  • Accessible forms

AA

  • Live video captions
  • Audio description of video
  • Contrast (4.5:1)
  • Zoom/resizing
  • No images of text
  • Navigation alternatives
  • Clear headings/labels
  • Consistent menus, icons, buttons
  • Error suggestion, prevention

Web Content Accessibility Guidelines (WCAG) 2.0

Semantics

Semantics

  • JS can be used to make anything do anything
    • You probably shouldn't if you can be semantic instead
  • Use elements for their intended purpose
    • Buttons for buttons, lists for lists, tables, etc
    • E.g. a div is not a button
    • Usually means less CSS/JS/extra attributes
  • Use headings (correctly)
  • Use the title tag
  • Make sure your markup is valid!
    • e.g. No duplicate IDs, correct nesting
    • Validator

Lists

  • Markup all visual lists
  • Know the different list types and when to use them
  • Group related links into lists
<ul>
    <li>Apples</li>
    <li>Oranges</li>
</ul>

<ol>
    <li>Peel the banana</li>
    <li>Eat the banana</li>
    <li>Throw the peel at Luigi</li>
</ol>

<dl>
    <dt>Name</dt>    
    <dd>Godzilla</dd>
    <dt>Born</dt>
    <dd>1952</dd>
    <dt>Birthplace</dt>
    <dd>Japan</dd>
    <dt>Color</dt>
    <dd>Green</dd>
</dl>

Headings

  • Use a logical structure (h1-h6)
  • Know when to use them
  • Also know when not to use them
    • Not just for making text bigger or emphasizing
  • h1-h6 should be an appropriate title for following content
  • Only 1 h1 - it should accurately describe the purpose of the page and come before (most) other content
  • Not just for accessibility - helps SEO too
  • HTML5 muddies it a bit

Links

  • All links should make sense out of context
  • "Click here" = bad
  • "Learn more" = bad
  • Describe where the link is going between the tags
    • Or use title or aria-label
  • Empty hash links = bad (unless you are intending to go to the top of the page)
  • Don't use anchor if it should be a button/input

Anchor vs button vs input

  • Anchor
    • Navigate to another page
    • Navigate to another part of the same page
    • Download something
  • Button
    • Submit or reset forms
    • Activate custom functionality
  • Input
    • Receive and store data

The final showdown

Tables

  • Don't use tables
  • Except when you should
    • e.g. tabular data
  • thead, tbody, tfoot
  • col, colgroup
  • th (don't forget scope)
  • td (don't forget headers if multiple th's)
  • Descriptions for complex tables

Why did the web developer leave the restaurant?

Because of the table layout.

Images

  • All images require the alt attribute
  • Empty alt (e.g. alt="") means the image is decorative
  • No alt attribute means screen reader will read out the filename (which is almost always bad)
  • Be descriptive
  • An empty alt is usually better than a bad alt
  • Avoid infographics and images with text
    • Or provide a detailed textual summary
  • Avoid flashing

Audio and Video

  • Don't autoplay (unless it's expected)
  • Provide controls
  • Provide text alternative
  • Avoid flashing

Forms

  • Provide instructions for form before the form tag
  • All fields need label (use for/id)
  • Mark required fields (programmatically and visually)
    • If using *, define it
  • Use fieldsets with legends for related fields
    • Sets of multiple radio/checkboxes
<p>All fields marked with an asterisk (*) are required</p>
<form>
    <label for="email">
        Email
        <span title="Required">*</span>
    </label>
    <input type="email" id="email" required>
    <button type="submit">Submit</button>
</form>

Form Errors

Form Errors

  • Provide summary at top in UL, each item linking to the associated field (don't forget to move focus)
  • Add error to each field
  • Provide hints for valid input

Keyboard

  • Provide keyboard alternatives
  • Skip links
  • Provide more than one way to navigate the site (e.g. sitemaps)
  • All interactive elements should be accessible
  • Tab/focus management
  • Don't let user get lost or stuck (e.g. pop-ups, modals, off-canvas)
  • Don't be unpredictable
  • Focus order matters
  • If you apply :hover styles, consider :focus too
    • Don't use colour alone

Visual

  • Entire site should be readable and usable up to 200% zoom
  • Contrast
    • 4.5:1 contrast between the non-link text color
      and background.
    • 4.5:1 contrast between the link text color
      and background.
    • A 3:1 contrast between the link text color
      and the surrounding non-link text color.
  • Screen readers hide elements from their users when they are styled using display none and visibility hidden
    • ​sr-only css

WAI-ARIA

  • First rule of using aria is not to use aria
  • Roles
    • main, complementary, navigation, search, banner, contentinfo, alert
  • Properties
    • aria-labelledby, aria-label, aria-describedby
    • aria-required
  • States
    • aria-controls, aria-expanded, aria-hidden
    • aria-disabled

Tools & Resources

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