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ionic-framework/core
Maria Hutt 7294e969bb fix(backdrop): remove tabindex for improved accessibility (#29956)
Issue number: resolves #29773

---------

<!-- Please do not submit updates to dependencies unless it fixes an
issue. -->

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etc). Submit multiple pull requests if needed. -->

## What is the current behavior?
<!-- Please describe the current behavior that you are modifying. -->

Certain Chrome and Edge versions (confirmed: Chrome v127 and Edge v127)
would indicate that the backdrop has an accessibility violation:

```
Blocked aria-hidden on a <ion-backdrop> element because the element that just received
focus must not be hidden from assistive technology users. Avoid using aria-hidden on a
focused element or its ancestor. Consider using the inert attribute instead, which will also
prevent focus. For more details, see the aria-hidden section of the WAI-ARIA specification at
```

The error is happening because `tabindex` and `aria-hidden` are being
passed to `ion-backdrop`. The `tabindex` attribute is used to make an
element focusable, regardless of value. When `aria-hidden` is applied to
an element, then the element is hidden from screen readers. This
violates the accessibility standards since `ion-backdrop` would be
considered a focusable element but not visible to screen readers.

## What is the new behavior?
<!-- Please describe the behavior or changes that are being added by
this PR. -->

- Removed `tabindex`, this aligns with frameworks known for
accessibility (Chakra UI)

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

<!--
  If this introduces a breaking change:
1. Describe the impact and migration path for existing applications
below.
  2. Update the BREAKING.md file with the breaking change.
3. Add "BREAKING CHANGE: [...]" to the commit description when merging.
See
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for more information.
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## Other information

<!-- Any other information that is important to this PR such as
screenshots of how the component looks before and after the change. -->

Dev build: `8.3.4-dev.11729533091.1ac77a0c`

How to test:

1. Use either Chrome v127 or Edge v127
2. Navigate to the [alert basic
page](https://ionic-framework-3pvgcj4b9-ionic1.vercel.app/src/components/alert/test/basic)
from the `main` branch
3. Open browser console
4. Click on the first button on the alert page
5. Click on the backdrop
6. Notice the error message in the browser console (if you don't see it,
then use a private browser or clear cache)
7. Navigate to the [alert basic
page](https://ionic-framework-git-rou-11175-ionic1.vercel.app/src/components/alert/test/basic)
from the `ROU-11175` branch
8. Repeat steps 2-6
9. Verify that the error does not appear
2024-10-22 15:07:36 +00:00
..
2024-10-16 18:55:50 +00:00
2024-10-16 18:55:50 +00:00

@ionic/core

Ionic is an open source App Development Framework that makes it easy to build top quality Native and Progressive Web Apps with web technologies.

The Ionic Core package contains the Web Components that make up the reusable UI building blocks of Ionic Framework. These components are designed to be used in traditional frontend view libraries/frameworks (such as Stencil, React, Angular, or Vue), or on their own through traditional JavaScript in the browser.

Features

  • Tiny, highly optimized components built with Stencil
  • Styling for both iOS and Material Design
  • No build or compiling required
  • Simply add the static files to any project
  • Lazy-loaded components without configuration
  • Asynchronous rendering
  • Theming through CSS Variables

How to use

Vanilla HTML

Easiest way to start using Ionic Core is by adding a script tag to the CDN:

<script type="module" src="https://cdn.jsdelivr.net/npm/@ionic/core/dist/ionic/ionic.esm.js"></script>
<script nomodule src="https://cdn.jsdelivr.net/npm/@ionic/core/dist/ionic/ionic.js"></script>
<link href="https://cdn.jsdelivr.net/npm/@ionic/core/css/ionic.bundle.css" rel="stylesheet">

Any Ionic component added to the webpage will automatically load. This includes writing the component tag directly in HTML, or using JavaScript such as document.createElement('ion-toggle').

Additionally, within this package is a dist/ionic.js file and accompanying dist/ionic/ directory. These are the same files which are used by the CDN, and they're available in this package so they can be apart of an app's local development.

Framework Bindings

The @ionic/core package can be used in simple HTML, or by vanilla JavaScript without any framework at all. Ionic also has packages that make it easier to integrate Ionic into a framework's traditional ecosystem and patterns. (However, at the lowest-level framework bindings are still just using Ionic Core and Web Components).

Custom Elements Build

In addition to the default, self lazy-loading components built by Stencil, this package also comes with each component exported as a stand-alone custom element within @ionic/core/components. Each component extends HTMLElement, and does not lazy-load itself. Instead, this package is useful for projects already using a bundler such as Webpack or Rollup. While all components are available to be imported, the custom elements build also ensures bundlers only import what's used, and tree-shakes any unused components.

Below is an example of importing ion-badge, and initializing Ionic so it is able to correctly load the "mode", such as Material Design or iOS. Additionally, the initialize({...}) function can receive the Ionic config.

import { defineCustomElement } from "@ionic/core/components/ion-badge.js";
import { initialize } from "@ionic/core/components";

// Initializes the Ionic config and `mode` behavior
initialize();

//  Defines the `ion-badge` web component
defineCustomElement();

Notice how we import from @ionic/core/components as opposed to @ionic/core. This helps bundlers pull in only the code that is needed.

The defineCustomElement function will automatically define the component as well as any child components that may be required.

For example, if you wanted to use ion-modal, you would do the following:

import { defineCustomElement } from "@ionic/core/components/ion-modal.js";
import { initialize } from "@ionic/core/components";

// Initializes the Ionic config and `mode` behavior
initialize();

//  Defines the `ion-modal` and child `ion-backdrop` web components.
defineCustomElement();

The defineCustomElement function will define ion-modal, but it will also define ion-backdrop, which is a component that ion-modal uses internally.

Using Overlay Controllers

When using an overlay controller, developers will need to define the overlay component before it can be used. Below is an example of using modalController:

import { defineCustomElement } from '@ionic/core/components/ion-modal.js';
import { initialize, modalController } from '@ionic/core/components';

initialize();
defineCustomElement();

const showModal = async () => {
  const modal = await modalController.create({ ... });
  
  ...
}

How to contribute

Check out the CONTRIBUTE guide

License