focus-lock

DOM trap for a focus

Usage no npm install needed!

<script type="module">
  import focusLock from 'https://cdn.skypack.dev/focus-lock';
</script>

README

focus-lock

It is a trap! We got your focus and will not let him out!

NPM

Consumers

This is a base package for:

Provides a low level API, to be used by final realization. Usually everything can be solved in 3 lines

import moveFocusInside, { focusInside } from 'focus-lock';

if (topNode && !focusInside(topNode)) {
  moveFocusInside(topNode, lastActiveFocus);
}

Additional API

Programmatic focus management

import { focusNextElement, focusPrevElement } from 'focus-lock';
focusNextElement(sourceElement, {
  scope: theBoundingDOMNode,
}); // -> next tabbable element

WHY?

From MDN Article about accessible dialogs:

  • The dialog must be properly labeled
  • Keyboard focus must be managed correctly

This one is about managing the focus.

I'v got a good article about focus management, dialogs and WAI-ARIA.

Focus fighting

It is possible, that more that one "focus management system" is present on the site. For example, you are using FocusLock for your content, and also using some Modal dialog, with FocusTrap inside.

Both system will try to do their best, and move focus into their managed areas. Stack overflow. Both are dead.

Focus Lock(React-Focus-Lock, Vue-Focus-Lock and so on) implements anti-fighting protection - once the battle is detected focus-lock will surrender(as long there is no way to win this fight).

You may also land a peace by special data attribute - data-no-focus-lock(constants.FOCUS_ALLOW). It will remove focus management from all nested elements, letting you open modals, forms, or use any third party component safely. Focus lock will just do nothing, while focus is on the marked elements.

API

default(topNode, lastNode) (aka setFocus), moves focus inside topNode, keeping in mind that last focus inside was - lastNode

Licence

MIT