The inert attribute/property allows web authors to mark parts of the DOM tree
as inert:

> When a node is inert, then the user agent must act as if the node was absent
> for the purposes of targeting user interaction events, may ignore the node for
> the purposes of text search user interfaces (commonly known as "find in
> page"), and may prevent the user from selecting text in that node.

Furthermore, a node which is inert should also be hidden from assistive
technology.

Details

- Read the Explainer.
- Read the Spec.
- Try the Demo.
- Give feedback!

Polyfill

Installation

npm install --save wicg-inert

We recommend only using versions of the polyfill that have been published to
npm, rather than cloning the repo and using the source directly. This helps
ensure the version you're using is stable and thoroughly tested.

This project provides two versions of the polyfill in package.json.

- main: Points at dist/inert.js which is transpiled to ES3.
- module: Points at dist/inert.esm.js which is transpiled to ES3.

_If you do want to build from source, make sure you clone the latest tag!_

Usage

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``
import "wicg-inert";
`

OR…

`html
...



`

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`js
const el = document.querySelector('#my-element');
el.inert = true; // alternatively, el.setAttribute('inert', '');
`

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If you want to use inert with an older browser you'll need to include
additional polyfills for
Map,
Set,
Element.prototype.matches,
and Node.prototype.contains.

In accordance with the W3C's new polyfill
guidance,
the inert polyfill does not bundle other polyfills.

You can use a service like https://cdnjs.cloudflare.com/polyfill
to download only the polyfills needed by the current browser. Just add the
following line to the start of your page:

`html

`

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By default, this polyfill will dynamically insert some CSS, which requires the
style-src rule of your Content Security Policy to allow 'unsafe-inline'.

It is possible avoid doing so by including those rules from a CSS stylesheet, as
follows (the id property is used by the polyfill to know if it needs to
dynamically add the missing rules):

`html

`

The stylesheet should include the following rules:

`css
[inert] {
pointer-events: none;
cursor: default;
}

[inert], [inert] * {
user-select: none;
-webkit-user-select: none;
-ms-user-select: none;
}
`

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The polyfill attempts to provide a reasonable fidelity polyfill for the inert
attribute, however please note:

- It relies on mutation observers to detect the addition of the inert
attribute, and to detect dynamically added content within inert subtrees.
Testing for _inert_-ness in any way immediately after either type of mutation
will therefore give inconsistent results; please allow the current task to end
before relying on mutation-related changes to take effect, for example via
setTimeout(fn, 0) or Promise.resolve().

Example:
`js
const newButton = document.createElement('button');
const inertContainer = document.querySelector('[inert]');
inertContainer.appendChild(newButton);
// Wait for the next microtask to allow mutation observers to react to the
// DOM change
Promise.resolve().then(() => {
expect(isUnfocusable(newButton)).to.equal(true);
});
`
- Using the inert property, however, is synchronous.

- The polyfill will be expensive, performance-wise, compared to a native inert
implementation, because it requires a fair amount of tree-walking. To mitigate
this, we recommend not using inert during performance sensitive actions
(like during animations or scrolling). Instead, wait till these events are
complete, or consider using
requestIdleCallback
to set inert.

Testing

Tests are written using ES5 syntax. This is to avoid needing to transpile them
for older browsers. There are a few modern features they rely upon, e.g.
Array.from and Promises. These are polyfilled for the tests using
https://cdnjs.cloudflare.com/polyfill. For a list of polyfilled features, check out
the polyfill section in karma.conf.js`.

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Cross-browser Testing Platform and Open Source <3 Provided by [Sauce Labs][homepage]

[homepage]: https://saucelabs.com