Accessible Form Error Checking

There are two ways to make accessible forms: the native HTML5 way, or using JavaScript. You would think it would be a no-brainer to just code things the HTML5 way and call it a day instead of creating custom code. However, many designers don't like the design of native HTML5 error message "bubbles", and want/demand that flexibility. Since there doesn't seem to be any easy cross-browser workaround for this, I have labelled both of the solution below good for new and existing work: the HTML5 one is good if you want to implement validation quickly, and the custom JavaScript implementation is good if you want design flexibility.

Using native HTML5 validation

This is great if you want to implement validation quickly and don't care about the styling restrictions of native HTML5 validation.

You can use just required and pattern attributes on HTML forms to do client side validation without JavaScript. However, in order to make the messaging more accessible, we have added a tiny bit of JavaScript code (inspired by this accessible HTML5 forms code demo by Paul J Adam) in order to ensure the error messages themselves are more accessible to screen reader users (see the last step in the code walkthrough for details)

Using custom validation

This solution is good if you want custom styling of the error messages

The solution below involves using Enable's accessibility.js library to make it easier to code. (Module installation instructions)

You can do the custom validation as well, but you have to ensure that when the form submits and there is an error, the first input value with an error receives focus so that keyboard and/or screen reader users can correct mistakes easily. You also have to ensure that form errors are marked up as <label> tags for the form fields they are associated with.

The following example used jQuery.validate() which is not accessible. We do not recommend to use this library for new projects ... it is just used as an example of how we can take existing code and make it accessible. If you want information about how to make forms accessible with JavaScript in the general sense, please read Alison Walden's excellent article on form validation.

Installation Instructions

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

• as an ES6 module using Webpack.
• as a CommonJS module using require() and Webpack.
• as a native ES6 module within the browser.
• as an old-school ES4/JavaScript library.

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:

• Jan Olaf Krems gives a great overview of the JavaScript File Format Differences
• Joe Honton discusses that With ES Modules and HTTP/2 You May Not Need Webpack Anymore
• Stack Overflow has a really good thread about Webpack vs ES6 modules as well.

Using NPM/Webpack to load ES6 Modules:

1. Install the enable-a11y NPM project.
2. Edit your webpack.config.json file to resolve the ~ modifier by adding the following:
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   module.exports = { ... resolve: { extensions: ['.js', '.jsx', '.scss', '.css', '*.html'], modules: [ path.resolve('./src/js'), path.resolve('./node_modules') ], alias: { '~enable-a11y': path.resolve(__dirname, 'node_modules/enable-a11y') ,'../enable-libs/accessibility-js-routines/dist/accessibility.module.js': path.resolve(__dirname, 'node_modules/accessibility-js-routines/dist/accessibility.module') }, ... }, ... }
3. You can use the module like this:
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   // import the JS module import accessibility from '~enable-a11y/js/modules/accessibility'; // import the CSS for the module import '~enable-a11y/css/accessibility'; // How to initialize the accessibility library accessibility.init();
4. 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/accessibility';
   (If you are using it in your CSS, you will have to add the .css suffix)

Using NPM/Webpack to Load Modules Using CommonJS Syntax

1. Install the enable-a11y NPM project.
2. You can import the module using require like this:
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   var accessibility = require('enable-a11y/accessibility').default; ... accessibility.init();
3. You will have to include the CSS as well in your project's CSS using:
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   @import '~enable-a11y/css/accessibility';

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/accessibility.js , and css/accessibility.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/accessibility.css" > ... </head> <body> ... </body> </html>
4. Load your scripts using the follwing code (NOTE: you must use <script type="module">):
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   <script type="module"> import accessibility from "path-to/accessibility.js" accessibility.init(); </script>

Using ES4