The ARIA Switch Role

A switch is like a checkbox, in that is designed to be an input control that has a binary value (either checked and unchecked or on or off, depending on the screenreader). Like tablists.php, switches do not have a native HTML5 tag, so we implement custom code using the switch role in JavaScript.

Many developers will implement switches using the <input type="checkbox">, since the native HTML5 checkbox control is already accessible. While you could do this, I would argue this is semantically dishonest: partially sighted users who use a screen reader hear that the control is a checkbox, but there is no checkmark involved.

My father, who is partially sighted, has fallen in this trap on a website once on his tablet. He was afraid of submitting an order form because he felt that the screen reader was lying to him, and he afraid of making a mistake because he didn't know what the control really did (he wasn't sure what it was, but it certainly didn't look like a checkbox). He tried to explain to me this issue over the phone, and after quite a few minutes not understanding what the trouble was, I went over to his house to see what he was talking about. After looking at his tablet, I learned a valuable lesson: developers shouldn't be dishonest to users to make things easier for themselves.

A simple switch coded with ARIA.

This is the best solution to use, especially when building from scratch.
If you already are using a component similar to this in existing work that is not accessible, go to the developer walkthrough of this section to see we made our implementation accessible.
This solution described below is available as an NPM module. (Module installation instructions)

This code is based on information from the MDN article on Using the switch role. The switch reports the checked state as "on" or "off" in VoiceOver and "checked" or "unchecked" in NVDA and ChromeVox. In order to make some consistancy among user agents, an aria-describedby on the switch can state the "on/off" state to all screen readers. This description is also given visually, to make it obvious what the state is for sighted users. Developers could hide this text with the sr-only class, and put "off" and "on" labels on sides of the right and left sides of the component if they wish instead.

Example code explanation

Below is the HTML of the above example. Use the dropdown to highlight each of the individual steps that makes the example accessible.

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Installation Instructions

You can load this JavaScript library into your application in serveral ways:

If you haven't done so already, choosing which you should use is obviously a major architectural decision. Here are a few articles that will help you decide:

Using NPM/Webpack to load ES6 Modules:

  1. Install the enable-a11y NPM project. Developers who are using webpack should know how to configure webpack to import the enable modules correctly.
  2. You can use the module like this:
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    // import the JS module import switch from '~enable-a11y/js/modules/switch'; // import the CSS for the module import '~enable-a11y/css/switch'; // How to initialize the switch library switch.init(); // Note that this component will work with DOM elements coded like // the examples above added after page load. There is no need to call // an .add() method, like we do with the Enable combobox component.
  3. Alternatively, if you are using LESS you can include the styles in your project's CSS using:
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    @import '~enable-a11y/css/switch';
    (If you are using it in your CSS, you will have to add the .css suffix)

Using ES6 modules natively.

This is the method that this page you are reading now loads the scripts.

  1. Grab the source by either using NPM, grabbing a ZIP file or cloning the enable source code from github.
  2. If you want to load the module as a native ES6 module, copy js/modules/switch.js, and css/switch.css from the repo and put them in the appropriate directories in your project (all JS files must be in the same directory).
  3. Load the CSS in the head of you document:
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    <html> <head> ... <link rel="stylesheet" href="path-to/css/switch.css" > ... </head> <body> ... </body> </html>
  4. Load your scripts using:
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    <script type="module"> import switch from "path-to/switch.js" switch.init(); </script>

Using ES4

Just do the same as the ES6 method, except you should get the JavaScript files from the js/modules/es4 directory instead of the js/modules/:
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<script src="path-to/es4/switch.js"></script>