 Resources from Erin Doyle in 2021

A large number of people are unable to use the web effectively due to an impairment or disability.

As developers there are several tools and techniques we can use to make our web applications accessible, ensuring a great user experience that includes everyone.

We all agree that Accessibility is important. However, it’s a broad landscape and can be overwhelming figuring out where to start!

Erin Doyle is an expert in creating accessible React applications and has developed a course that will give you a concrete process for testing, refactoring, and building your applications with accessibility in mind.

After this course, you'll have a jump start on auditing and fixing accessibility issues in your applications and gain a better understanding of your target users and how to approach your web app design from their perspectives.


React is one of the web’s most popular frameworks for building JavaScript applications. 

If you know what you’re doing, React can drastically simplify how you build, use, and maintain code.

Whether you’re a React newbie or you’re ready for advanced techniques, you can level-up with egghead. Explore our in-depth courses, lessons, and community resources to build more powerful applications and crack open your career.

react

Develop Accessible Web Apps with React

Building Accessible React Apps with Erin Doyle

Bite-size video tutorials for badass web developers.

egghead

Live Workshop Recording

Welcome and thank you for signing up for the workshop on Building Accessible Web Apps with React!  To be ready to hit the ground running there are some pre-requisites you'll need to have prepared:

1. Please walk step-by-step through the [README](https://github.com/erin-doyle/egghead-react-a11y) in the Github repo for the workshop.  
2. In addition, I've added some videos here that may be helpful to you if you're planning to use the VoiceOver screen reader on Mac or if you'll be using High Contrast Mode on Windows.

The rest of the tools I'll demo for you in the workshop but make sure you have them installed (which is all listed in the [README](https://github.com/erin-doyle/egghead-react-a11y)).

Thanks and I look forward to talking with you about React and Accessibility soon!

Building Accessible Web Apps with React Workshop Prep

Our first layer of defense when building accessible React applications is to add some auditing tools to our development workflow. This should include adding static analysis checking for common accessibility standards and best practices. We can get this with the latest eslint plugin: "eslint-plugin-jsx-a11y". If you are already linting your projects adding this plugin should fit very smoothly into your workflow.

## Resources
1. [List of all the rules supported by eslint-plugin-jsx-a11y](https://github.com/evcohen/eslint-plugin-jsx-a11y#supported-rules)
2. [Comparison of the difference in rules between recommended and strict mode](https://github.com/evcohen/eslint-plugin-jsx-a11y#difference-between-recommended-and-strict-mode)
3. [Background on how the Accessibility API implemented by browsers interfaces with Assistive Technologies](https://github.com/evcohen/eslint-plugin-jsx-a11y#some-background-on-wai-aria-the-ax-tree-and-browsers)

Set up ESLint to Audit Accessibility Issues in React

screen-reader

Learn how to access the VoiceOver training and utility preferences on MacOs and how to make customizations to the screen reader.

Access and Customize VoiceOver Settings on MacOS

Learn the basics of navigating through a web page using VoiceOver on MacOS in Safari.

Navigate a Webpage with VoiceOver in Safari

Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft. Each family caters to a certain sector of the computing industry.

microsoft

Learn the various ways to access and enable High Contrast Mode on Windows.

Enable High Contrast Mode on Windows

Continuing to add to our accessibility auditing toolset: react-axe goes hand in hand with eslint and specifically the eslint-plugin-jsx-a11y plugin.  While eslint analyzes our static code, react-axe is able to audit the elements that are available in the DOM at runtime.  As components get rendered into the DOM by React, react-axe is able to immediately check them for potential accessibility issues and will output any findings to the console.  Adding this tool to our workflow gives us accessibility checking as we're developing so that we can eliminate a plethora of potential issues as early as possible.

## Resources
* [List of all rules supported by react-axe](https://github.com/dequelabs/axe-core/blob/develop/doc/rule-descriptions.md)
* [Documentation of the Configuration Object](https://github.com/dequelabs/axe-core/blob/master/doc/API.md#api-name-axeconfigure)
* [How Deque Labs makes decisions on axe rules](https://github.com/dequelabs/axe-core/blob/develop/doc/accessibility-supported.md)

Use react-axe to Audit Accessibility Issues at Runtime during Development

The Chrome Developer Tools (DevTools for short), are a set of web authoring and debugging tools built into Google Chrome.

chrome-devtools

The axe browser extension (for Chrome and Firefox) is an immensely helpful tool for auditing web pages for accessibility defects.  This extension is powered by the same rules engine developed by Deque Labs in their axe-core open source library which also powers the react-axe development tool.  Each reported defect offers a ton of information about the defect, why it's a problem, severity level, groups impacted and ways to fix the defect.  This can be a great resource for learning more about how to write accessible code.

## Resources
* [Chrome browser extension](https://chrome.google.com/webstore/detail/axe-web-accessibility-tes/lhdoppojpmngadmnindnejefpokejbdd)
* [Firefox browser extension](https://addons.mozilla.org/en-US/firefox/addon/axe-devtools/)

Use the axe Browser Extension to Audit a Web Page for Accessibility Issues

Landmark regions are used by screen readers to make it easier for users to navigate the content on the page by defining the structure of the page.  Tools like the Rotor in VoiceOver rely on landmark regions to provide users with the ability to skip directly to the desired section of the page.  We can do this either using HTML5 landmark elements or `<div>` elements with aria roles. In the past, the recommendation was to use both but now we should only use one or the other.

The following are ARIA roles for landmark regions:
* `banner`
* `complementary`
* `contentinfo`
* `form`
* `main`
* `navigation`
* `search`
* `application`

## References
* https://dequeuniversity.com/assets/html/jquery-summit/html5/slides/landmarks.html
* https://www.w3.org/WAI/GL/wiki/Using_ARIA_landmarks_to_identify_regions_of_a_page
* https://www.w3.org/TR/html-aria/#docconformance

Define Landmark Regions of a web page using ARIA roles

WAI-ARIA, the Accessible Rich Internet Applications Suite, defines a way to make Web content and Web applications more accessible to people with disabilities. It especially helps with dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies. 

aria

tota11y is a great tool to add to your accessibility auditing toolkit.  tota11y is a browser extension available for Chrome and Firefox that helps visualize accessibility violations (and successes), while educating on best practices.  It can make for a really helpful supplement to other accessibility auditing tools.

## Resources
* [About tota11y](https://khan.github.io/tota11y/)
* [Chrome browser extension](https://chrome.google.com/webstore/detail/tota11y-plugin-from-khan/oedofneiplgibimfkccchnimiadcmhpe?hl=en)
* [Firefox browser extension](https://addons.mozilla.org/en-US/firefox/addon/tota11y-accessibility-toolkit/)

Use tota11y to Visualize Accessibility Issues

It's very important to experience our web applications using the tools and techniques that our users are using.  Many of our users out there may have vision impairments and may use tools or adjust settings to help them see better. Learn how to change the accessibility display preferences on Mac to test your application for issues that may arise due to a lack of contrast between foreground and background colors in your web application which can be exacerbated when users have to adjust these display preferences.

## Resources
* [MacOS Display Preferences User Guide] (https://support.apple.com/guide/mac-help/change-accessibility-display-preferences-unac089/mac)

Change Display Preferences on Mac to Find Color Contrast Accessibility Issues

A modern web browser owned and maintained by Google.

chrome

It's very important to experience our web applications using the tools and techniques that our users are using. Many of our users out there may have vision impairments and may use tools to help them see better. Learn how to use a High Contrast browser extension to see your web application the way many of your users may be seeing it.  You may discover that a lack of contrast between foreground and background colors will cause things to be hard to see or even invisible in certain High Contrast tool settings.

## Resources
* [Chrome browser extension](https://chrome.google.com/webstore/detail/high-contrast/djcfdncoelnlbldjfhinnjlhdjlikmph)

Use a High Contrast Browser Extension to Find Color Contrast Accessibility Issues

Using our accessibility auditing toolkit we can find issues concerning landmark regions in our web application.  The react-axe library will report findings in the JavaScript console of the browser.  We could also run the axe browser extension to see the same results.  The tota11y browser extension will annotate any landmark regions on the page and therefore if none are annotated it may indicate that they aren't any (_NOTE: tota11y will only annotate landmark regions using aria roles and not those using HTML5 elements_).  Finally using the VoiceOver Rotor in Safari will show us whatever landmark regions have been defined in the Landmarks menu. 

Test for Landmark Region Accessibility Issues in React

Landmark regions are used by screen readers to make it easier for users to navigate the content on the page by defining the structure of the page. Tools like the Rotor in VoiceOver rely on landmark regions to provide users with the ability to skip directly to the desired section of the page. We can do this either using HTML5 landmark elements or <div> elements with aria roles. In the past, the recommendation was to use both but now we should only use one or the other.  We should prefer HTML5 to ARIA roles when possible.

The following are HTML5 elements for landmark regions:
* article
* aside
* header
* footer
* main
* nav
* section

## References
* https://dequeuniversity.com/assets/html/jquery-summit/html5/slides/landmarks.html
* https://www.a11ymatters.com/article/intro-html5-sectioning-elements/
* https://www.w3.org/TR/html-aria/#docconformance

Define Landmark Regions of a web page using HTML5 sectioning elements

We can find issues with heading levels by utilizing our accessibility auditing tools.  The library react-axe, as well as the browser extension axe, will report any findings concerning heading levels.  The browser extension tota11y will annotate all heading levels on a page and show any in red that have issues.  Finally, we can check the Rotor in VoiceOver in Safari.  The Rotor should have a Headings menu and will list in order all of them that are found on the page.  If headings are missing or inappropriate this will help us find them as well.

Test for Heading Level Accessibility Issues

Similar to Landmark Regions, Heading Levels are used by web browsers, plug-ins, and assistive technologies to provide in-page navigation.

## Rules
* Each page should have at least one `<h1>`
* Pages should be structured in a hierarchical manner
    * `<h1>`: being the most important (usually page titles or main content heading)
    * `<h2>`: usually major section headings
    * `<h3>`: sub-sections of the `<h2>`
    * and so on
* Do not skip heading levels - always follow consecutive order
* Do not use text formatting, such as font size or bold to give the visual appearance of headings.  
    * Use actual heading (`<h1>` - `<h6>`) for all content headings
* Do not use heading levels to achieve visual results only

## References
* https://webaim.org/techniques/semanticstructure/
* https://www.w3.org/WAI/tutorials/page-structure/headings/

Correctly Define Heading Levels of a Web Page

The pluggable linting utility for JavaScript and JSX.

eslint

We have a number of options to use when testing for accessibility issues concerning alternative text for images.  The react-axe library and axe browser extension will both report when an image is missing alternative text.  The tota11y browser extension will annotate any images that are missing alternative text.  Running eslint with the eslint-plugin-jsx-a11y plugin installed will report on any `<img>` elements missing an `alt` attribute.  Finally, we can use a screen reader to actually hear what is read when an image has focus.

Test for Image Alternative Text Accessibility Issues

Images must have text alternatives that describe the information or function 
represented by them so they can be read and understood by those using screen readers.

## Alternative text for images
* All `<img>` elements should have an `alt` attribute provided
    * When not provided many screen readers will fallback to reading the file name instead
* The `alt` value should not include words like _“image”_, _“picture”_ or _“icon”_
    * Screen readers are already announcing that the element is an image
* Images that are decorative only and provide no information or function to the page should be hidden from Assistive Technologies by providing an empty `alt` attribute (`alt=””`)

## References
* https://www.w3.org/WAI/tutorials/images/
* https://www.w3.org/WAI/tutorials/images/decision-tree/
* https://www.w3.org/WAI/tutorials/images/tips/
* https://www.w3.org/WAI/tutorials/images/informative/
* https://www.w3.org/WAI/tutorials/images/functional/
* https://www.w3.org/WAI/tutorials/images/textual/

Define Images with Appropriate Text Alternatives

When the contrast between foreground and background colors is not sufficient it can be hard to distinguish outlines, borders, edges, and details and text can be hard to read. The minimum recommended contrast ratio is 4.5:1 for most text. Very large text (120-150% larger than the default body text) can be slightly lower at 3:1. 

The contrast ratio of 4.5:1 was chosen because it compensates for the loss in contrast sensitivity usually experienced by users with vision loss equivalent to approximately 20/40 vision which is commonly reported as typical visual acuity of people at about age 80.

## References
* https://webaim.org/articles/contrast/
* https://webaim.org/resources/contrastchecker/
* [Accessible Color Picker Chrome browser extension](https://chrome.google.com/webstore/detail/accessible-color-picker/bgfhbflmeekopanooidljpnmnljdihld?hl=en-US)
* https://color.review/

Use Sufficient Color Contrast in Web Page Design

We should not use color alone as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.  Users may not be able to see/understand the differences in color and require additional indicators.

Along with color, use additional indicators such as:
* typography
* shapes
* grids
* spaces
* and/or allocate more weight to important elements

## References:
* http://www.particletree.com/features/interfaces-and-color-blindness/
* https://www.smashingmagazine.com/2014/10/color-contrast-tips-and-tools-for-accessibility/

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Erin Doyle