Learn Aria, Clojure and Dart

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

Dart is an object-oriented language you can use for building web applications, server-side code, and even mobile apps. It’s expressive, powerful, and has a friendly learning curve. 

In this course, we will look at the syntax and semantics of the Dart programming language. We will also cover various aspects of the Dart ecosystem, including its tools and packages that help make you a productive developer. This knowledge is applicable when developing software for client, server, and especially mobile with the Flutter framework. 

This course is beginner-friendly, but is well-suited for experience programmers as well. 

Dart is an open-source, scalable programming language, with robust libraries and runtimes, for building web, server, and mobile apps.

dart

Get Started with Dart

Accessibility (or a11y) is an important but often neglected in the world of web development. Many developers find themselves coding user interfaces without any knowledge of keyboard or screen reader requirements. 

The fact is that accessibility doesn't happen by accident. Often it is seen as too hard or time consuming. This doesn't have to be the case. By following a handful of high-value patterns and practices, we can open our web apps to humans that otherwise wouldn't be able to interact with them at all.

This course will introduce you to accessibility through hands-on, technical examples that are way more effective than reading 10-year-old static web content.



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

Start Building Accessible Web Applications Today

Skeleton screens show users that content is loading, offering a vague preview of how content will look once it fully loads.

CSS Animations are crucial for the perceived performance purposes since it shows for the user the content is loading by using animations as feedback for whoever is accessing the page. 

Follow the steps in this course and you will learn how to create a beautiful and pleasant Skeleton Loader for your web app using CSS animations, focusing on Web Accessibility and Web Semantic.

Creating Accessible Skeleton Loader Animation from Scratch with HTML and CSS

AngularJS is an open-source JavaScript framework, maintained by Google, that assists with running single-page applications. Its goal is to augment web-based applications with model–view–controller (MVC) capability, in an effort to make both development and testing easier.

angularjs

Themes convey meaning through color, tones, and contrasts. And the theme color palettes, alphas, and shadows deliver a consistent tone to your application and a unified feel for all Angular Material UI components. Theming allows developers to change the intention and meaning of the application by changing the colors and shadows. 

Accessibility is a huge - often overlooked - feature in modern web applications. Angular Material components all implement ARIA features whenever possible. And for usage scenarios where the ARIA attributes are not explicitly provided and cannot be inferred, then Angular Material will provide details console warnings alerting the developer.

Let’s use the Angular Material Theming service to change the background, primary, accent, and warning colors used within the entire application. These will be configured at startup using the $mdThemeProvider.  

Let’s also resolve the two ARIA warnings shown in console. These originate from icon buttons where the ARIA label cannot be inferred. So let’s add a static aria-label and a dynamic, interpolated aria-label to those buttons.

> This course presented by Thomas Burleson and Aaron Frost

Angular Material: Theming and ARIA

Icon buttons are very common in web applications, yet they often have accessibility problems. Learn how to make your icon buttons accessible to keyboard and screen reader users with HTML, CSS, SVG and ARIA.

Accessible Icon Buttons

Are you building a website or web application that takes user input? Then it's important for you to watch this demo. Learn how to create more accessible forms using basic HTML form labels, fieldsets and legends. You'll even learn a bit about what makes Safari's developer tools pretty awesome.

Building Forms with Accessibility in Mind

Webpages are more than simply how they look. By coding with headings, landmarks and semantic HTML, you can expose a rich document outline to users of assistive technologies, as well as search engines. 

Headings and semantic structure for accessible web pages

What is this thing called ARIA? In this lesson, you'll learn about about WAI-ARIA, a.k.a. Accessible Rich Internet Applications, the W3C spec for specifying accessibility information in HTML and SVG. I cover the basics of applying ARIA roles, states and properties, helpful information for creators of user-interface widgets and component libraries. But it's important to note that you might not need ARIA at all! Before using it, it's important to educate yourself on what ARIA does and doesn't do for you.

Intro to ARIA

Learn how to create a modal dialog with accessible keyboard and screen reader mechanics using the native HTML5 dialog element and experimental inert attribute (with polyfills) and JavaScript focus management. We'll explore how to make a DIV or non-modal dialog into a modal one to contrast the differences. Finally, we'll expose accessibility information for NVDA, Voiceover, JAWS and other screen readers.

For more details on creating accessible dialog content, check out this great article by Marco Zehe, Advanced ARIA Tip #2: Accessible Modal Dialogs: https://www.marcozehe.de/2015/02/05/advanced-aria-tip-2-accessible-modal-dialogs/

### Used in this lesson:
- Google dialog element polyfill: https://github.com/GoogleChrome/dialog-polyfill
- Inert attribute polyfill: https://github.com/WICG/inert

Accessible modal dialogs

Learn the basics of web accessibility testing using the keyboard, [Web Developer Toolbar](https://addons.mozilla.org/en-US/firefox/addon/web-developer/), [aXe Firefox extension](https://addons.mozilla.org/en-us/firefox/addon/axe-devtools/), and Lea Verou's [Contrast Ratio](http://leaverou.github.io/contrast-ratio/) tool. We'll look at how to get an overview of a webpage's accessibility, with special attention paid to solving color contrast issues.

For more on accessibility auditing, check out this article: https://marcysutton.com/how-i-audit-a-website-for-accessibility/

Basic accessibility testing

Testing for accessibility is easy with automated tools like axe-cli. This command-line tool utilizes the open source axe-core JavaScript library to run an audit on any webpage you give it, returning a set of JSON results you can use in your continuous integration environment or regular development workflow. 

- [axe-cli](https://github.com/dequelabs/axe-cli)
- [axe-core](https://https://github.com/dequelabs/axe-core)
- [aXe Chrome](https://chrome.google.com/webstore/detail/axe/lhdoppojpmngadmnindnejefpokejbdd?hl=en-US)

Accessibility testing with axe-cli

Often buttons need to be handled by JavaScript, and if done improperly it can lead to accessibility issues. In this lesson you will improve a major news organization's global header with some basic HTML and JavaScript.

Accessible Button Events

In this lesson, you will write a basic HTTP server in the Dart programming language. We will be using the HttpServer class from Dart's inbuilt 'dart:io' library to achieve this.

Dart is an object-oriented programming language by Google, which aims to help the developer build modern web applications. It covers client, server and now mobile with Flutter. It comes with a range of tools including a virtual machine, core libraries, and package management repository, lending enough ammunition to start your next project.

Learn more at https://dartlang.org


Write a Basic HTTP Server in Dart

In this lesson, you will setup your first command-line Dart application. We will install the SDK and write our first program. This will form the basis for future lessons where we further explore the Dart ecosystem.

Dart is an object-oriented programming language by Google, which aims to help the developer build modern web applications. It covers client, server and now mobile with Flutter. It comes with a range of tools including a virtual machine, core libraries, and package management repository, lending enough ammunition to start your next project.

Learn more at https://dartlang.org



Setup your first Dart project

In this lesson, we will look at how to create variables and constants. These are containers that store data for later reference and/or retrieval.

Dart is an object-oriented programming language by Google, which aims to help the developer build modern web applications. It covers client, server and now mobile with Flutter. It comes with a range of tools including a virtual machine, core libraries, and package management repository, lending enough ammunition to start your next project.

Learn more at https://dartlang.org

Understand Variables and Constants in Dart

In this lesson, we will cover Dart's inbuilt data types. Everything in Dart is an object, and therefore there are no primitive data types. In other words, all types extend a base type named Object. Any identifier without a value is set to null by default. There is no "undefined" value.

Dart is an object-oriented programming language by Google, which aims to help the developer build modern web applications. It covers client, server and now mobile with Flutter. It comes with a range of tools including a virtual machine, core libraries, and package management repository, lending enough ammunition to start your next project.

Learn more at https://dartlang.org

Understand Built-in types in Dart

Animations can make people sick, or worse! By adding animation toggles and listening in to the user's system preference for reducing motion on OSX and iOS, we can give them more control over our interfaces. Animation can be a safety issue; let's do something about it!

Warning: there is a flashing animation in the video.

In this lesson:
- [prefers-reduced-motion](https://webkit.org/blog/7551/responsive-design-for-motion/)

WCAG 2.1, Guideline 2.3: Seizure risks
- https://www.w3.org/WAI/WCAG21/quickref/?versions=2.0#qr-seizure-does-not-violate

Your Interactive Makes Me Sick
- https://source.opennews.org/articles/motion-sick/

Accessible animations with reduced motion

Because we'll be controlling our markup via JSX, we can use ESLint to check our markup for potential accessibility issues based on static analysis of the code. In this lesson, we'll install, configure and run the `jsx-a11y` ESLint plugin.

Check for Accessibility Issues in JSX with the jsx-a11y ESLint Plugin

The jsx-a11y lint plugin is a great first line of defense to prevent accessibility issues, but no tool can cover everything. React-axe gives us a runtime check on our rendered DOM, and by adding it to our boilerplate, we’ll ensure that all our future projects have accessibility covered from multiple angles. In this lesson, we’ll install react-axe and add it to our entry point for development builds only.

Check for Accessibility Issues in the Browser with react-axe

Clojure is a dynamic, general-purpose programming language, combining the approachability and interactive development of a scripting language with an efficient and robust infrastructure for multithreaded programming. Clojure is a compiled language, yet remains completely dynamic – every feature supported by Clojure is supported at runtime. Clojure provides easy access to the Java frameworks, with optional type hints and type inference, to ensure that calls to Java can avoid reflection.

clojure

We'll use Lumo, a cross-platform standalone ClojureScript compiler and Node.js environment, to create Hello as a command-line application. 

In this lesson, I’ll show you how to install Lumo through NPM, invoke a function in ClojureScript, and use the println function from the core library.