react-focus-lock
v2.13.2
Published
It is a trap! (for a focus)
Downloads
7,725,406
Readme
- browser friendly focus lock
- matching all your use cases
- trusted by best UI frameworks
- the thing Admiral Ackbar was talking about
It is a trap! We got your focus and will not let him out!
- Modal dialogs. You can not leave it with "Tab", ie do a "tab-out".
- Focused tasks. It will aways brings you back, as you can "lock" user inside a component.
- Any any other case, when you have to lock user intention and focus, if that's what
a11y
is asking for.- Including programatic focus management and smart return focus
Trusted
Trusted by Atlassian AtlasKit, ReachUI, SmoothUI, Storybook and we will do our best to earn your trust too!
Features
- no keyboard control, everything is done watching a focus behavior, not emulating it. Focus-Locks works for all cases including positive tab indexes.
- React Portals support. Even if some data is in outer space - it is still in lock.
- Scattered locks, or focus lock groups - you can setup different isolated locks, and tab from one to another.
- Controllable isolation level.
- variable size bundle. Uses sidecar to trim UI part down to 1.5kb.
💡 focus locks is part of a bigger whole, consider scroll lock and text-to-speech lock you have to use to really "lock" the user. Try react-focus-on to archive everything above, assembled in the right order.
How to use
Just wrap something with focus lock, and focus will be moved inside
on mount.
import FocusLock from 'react-focus-lock';
const JailForAFocus = ({onClose}) => (
<FocusLock>
You can not leave this form
<button onClick={onClose} />
</FocusLock>
);
Demo - https://codesandbox.io/s/5wmrwlvxv4.
API
FocusLock would work perfectly even with no props set.
FocusLock has few props to tune behavior, all props are optional:
disabled
, to disable(enable) behavior without altering the tree.className
, to set theclassName
of the internal wrapper.returnFocus
, to return focus into initial position on unmount
By default
returnFocus
is disabled, so FocusLock will not restore original focus on deactivation. This was done mostly to avoid breaking changes. We strong recommend enabling it, to provide a better user experience.
This is expected behavior for Modals, but it is better to implement it by your self. See unmounting and focus management for details
persistentFocus=false
, requires any element to be focused. This also disables text selections inside, and outside focus lock.autoFocus=true
, enables or disables focusing into on Lock activation. If disabled Lock will blur an active focus.noFocusGuards=false
disabled focus guards - virtual inputs which secure tab index.group='''
named focus group for focus scattering aka combined lock targetsshards=[]
an array ofref
pointing to the nodes, which focus lock should consider and a part of it. This is another way focus scattering.whiteList=fn
you could whitelist locations FocusLock should carry about. Everything outside it will ignore. For example - any modals.as='div'
if you need to change internaldiv
element, to any other. Use ref forwarding to give FocusLock the node to work with.lockProps={}
to pass any extra props (except className) to the internal wrapper.hasPositiveIndices=false
to support a focus lock behavior when any elements tabIndex greater than 0.crossFrame=true
enables aggressive focus capturing within iframes
Programmatic control
Focus lock exposes a few methods to control focus programmatically.
Imperative API
useFocusInside(nodeRef)
- to move focus inside the given nodeuseFocusScope():{autofocus, focusNext, focusPrev}
- provides API to manage focus within the current lockuseFocusState()
- manages focus state of a given nodeuseFocusController(nodeRef)
- low level version ofuseFocusScope
working without FocusLock
Declarative API
<AutoFocusInside/>
- causes autofocus to look inside the component<MoveFocusInside/>
- wrapper arounduseFocusInside
, forcibly moves focus inside on mount<FreeFocusInside/>
- hides internals from FocusLock allowing unmanaged focus
Indirect API
Focus-lock behavior can be controlled via data-attributes. Declarative API above is working by setting them for you. See corresponding section in focus-lock for details
Focusing in OSX (Safari/Firefox) is strange!
By default tabbing
in OSX sees
only controls, but not links or anything else tabbable
. This is system settings, and Safari/Firefox obey.
Press Option+Tab in Safari to loop across all tabbables, or change the Safari settings. There is no way to fix Firefox, unless change system settings (Control+F7). See this issue for more information.
Set up
Requirements
- version 1x is React 15/16 compatible
- version 2+ requires React 16.8+ (hooks)
Import
react-focus-lock
exposed 3 entry points: for the classical usage, and a sidecar one.
Default usage
- 4kb,
import FocusLock from 'react-focus-lock
would give you component you are looking for.
Separated usage
Meanwhile - you dont need any focus related logic until it's needed. Thus - you may defer that logic till Lock activation and move all related code to a sidecar.
- UI, 1.5kb,
import FocusLockUI from 'react-focus-lock/UI
- a DOM part of a lock. - Sidecar, 3.5kb,
import Sidecar from 'react-focus-lock/sidecar
- which is the real focus lock.
import FocusLockUI from "react-focus-lock/UI";
import {sidecar} from "use-sidecar";
// prefetch sidecar. data would be loaded, but js would not be executed
const FocusLockSidecar = sidecar(
() => import(/* webpackPrefetch: true */ "react-focus-lock/sidecar")
);
<FocusLockUI
disabled={this.state.disabled}
sideCar={FocusLockSidecar}
>
{content}
</FocusLockUI>
That would split FocusLock into two pieces, reducing app size and improving the first load. The cost of focus-lock is just 1.5kb!
Saved 3.5kb?! 🤷♂️ 3.5kb here and 3.5kb here, and your 20mb bundle is ready.
Autofocus
Use when you cannot use the native autoFocus
prop - because you only want to autofocus once the Trap has been activated
- prop
data-autofocus
on the element. - prop
data-autofocus-inside
on the element to focus on something inside. AutoFocusInside
component, as named export of this library.
import FocusLock, { AutoFocusInside } from 'react-focus-lock';
<FocusLock>
<button>Click</button>
<AutoFocusInside>
<button>will be focused</button>
</AutoFocusInside>
</FocusLock>
// is the same as
<FocusLock>
<button>Click</button>
<button data-autofocus>will be focused</button>
</FocusLock>
If there is more than one auto-focusable target - the first will be selected. If it is a part of radio group, and rest of radio group element are also autofocusable(just put them into AutoFocusInside) - checked one fill be selected.
AutoFocusInside
will work only on Lock activation, and does nothing, then used outside of the lock.
You can use MoveFocusInside
to move focus inside with or without lock.
import { MoveFocusInside } from 'react-focus-lock';
<MoveFocusInside>
<button>will be focused</button>
</MoveFocusInside>
Portals
Use focus scattering to handle portals
- using
groups
. Just create a few locks (only one could be active) with a same group name
const PortaledElement = () => (
<FocusLock group="group42" disabled={true}>
// "discoverable" portaled content
</FocusLock>
);
<FocusLock group="group42">
// main content
</FocusLock>
- using
shards
. Just pass all the pieces to the "shards" prop.
const PortaledElement = () => (
<div ref={ref}>
// "discoverable" portaled content
</div>
);
<FocusLock shards={[ref]}>
// main content
</FocusLock>
- without anything. FocusLock will not prevent focusing portaled element, but will not include them in to tab order
const PortaledElement = () => (
<div>
// NON-"discoverable" portaled content
</div>
);
<FocusLock shards={[ref]}>
// main content
<PortaledElement />
</FocusLock>
Using your own Components
You may use as
prop to change what Focus-Lock will render around children
.
<FocusLock as="section">
<button>Click</button>
<button data-autofocus>will be focused</button>
</FocusLock>
<FocusLock as={AnotherComponent} lockProps={{anyAnotherComponentProp: 4}}>
<button>Click</button>
<span>Hello there!</span>
</FocusLock>
Programmatic Control
Let's take a look at the Rowing Focus
as an example.
// Will set tabindex to -1 when is not focused
const FocusTrackingButton = ({ children }) => {
const { active, onFocus, ref } = useFocusState();
return (
<button tabIndex={active ? undefined : -1} onFocus={onFocus} ref={ref}>
{children}
</button>
);
};
const RowingFocusInternalTrap = () => {
const { autoFocus, focusNext, focusPrev } = useFocusScope();
// use useFocusController(divRef) if there is no FocusLock around
useEffect(() => {
autoFocus();
}, []);
const onKey = (event) => {
if (event.key === 'ArrowDown') {
focusNext({ onlyTabbable: false });
}
if (event.key === 'ArrowUp') {
focusPrev({ onlyTabbable: false });
}
};
return (
<div
onKeyDown={onKey}
// ref={divRef} for useFocusController
>
<FocusButton>Button1</FocusButton>
<FocusButton>Button2</FocusButton>
<FocusButton>Button3</FocusButton>
<FocusButton>Button4</FocusButton>
</div>
);
};
// FocusLock, even disabled one
const RowingFocusTrap = () => (
<FocusLock disabled>
<RowingFocusInternalTrap />
</FocusLock>
);
Guarding
As you may know - FocusLock is adding Focus Guards
before and after lock to remove some side effects, like page scrolling.
But shards
will not have such guards, and it might be not so cool to use them - for example if no tabbable
would be
defined after shard - you will tab to the browser chrome.
You may wrap shard with InFocusGuard
or just drop InFocusGuard
here and there - that would solve the problem.
import {InFocusGuard} from 'react-focus-lock';
// wrap with
<InFocusGuard>
<button />
</InFocusGuard>
// place before and after
<InFocusGuard />
<button />
<InFocusGuard />
InFocusGuards would be active(tabbable) only when tabble, it protecting, is focused.
Removing Tailing Guard
If only your modal is the last tabble element on the body - you might remove the Tailing Guard, to allow user tab into address bar.
<InFocusGuard/>
<button />
// there is no "tailing" guard :)
Unmounting and focus management
- In case FocusLock has
returnFocus
enabled, and it's going to be unmounted - focus will be returned after zero-timeout. - In case
returnFocus
is set tofalse
, and you are going to control focus change on your own - keep in mind
React will first call Parent.componentWillUnmount, and next Child.componentWillUnmount
This means - Trap will be still active by the time you may want move(return) focus on componentWillUnmount. Please deffer this action with a zero-timeout.
Similarly, if you are using the disabled
prop to control FocusLock, you will need a zero-timeout to correctly restore focus.
<FocusLock
disabled={isFocusLockDisabled}
onDeactivation={() => {
// Without the zero-timeout, focus will likely remain on the button/control
// you used to set isFocusLockDisabled = true
window.setTimeout(() => myRef.current.focus(), 0);
}
>
Return focus to another node
In some cases the original node that was focused before the lock was activated is not the desired node to return focus to. Some times this node might not exists at all.
- first of all, FocusLock need a moment to record this node, please do not hide it onClick, but hide onBlur (Dropdown, looking at you)
- second, you may specify a callback as
returnFocus
, letting you decide where to return focus to.
<FocusLock
returnFocus={(suggestedNode) => {
// somehow activeElement should not be changed
if(document.activeElement.hasAttributes('main-content')) {
// opt out from default behavior
return false;
}
if (someCondition(suggestedNode)) {
// proceed with the suggested node
return true;
}
// handle return focus manually
document.getElementById('the-button').focus();
// opt out from default behavior
return false;
}}
/>
Return focus with no scroll
read more at the issue #83 or mdn article.
To return focus, but without jumpy page scroll returning a focus you might specify a focus option
<FocusLock
returnFocus={{ preventScroll: false }} // working not in all browsers
>
Not supported by Edge and Safari.
Focus fighting
Two different focus-lock-managers or even different version of a single one, being active simultaneously will FIGHT for the focus. This usually totally breaks user experience.
React-Focus-Lock will automatically surrender, letting another library to take the lead.
Resolving focus fighting
You may wrap some render branch with FreeFocusInside
, and react-focus-lock will ignore
any focus inside marked node. So in case focus moves to uncontrolled location focus-lock will not trigger letting another library to act without interference in that another location.
import { FreeFocusInside } from 'react-focus-lock';
<FreeFocusInside>
<div id="portal-for-modals">
in this div i am going to portal my modals, dont fight with them please
</div>
</FreeFocusInside>
Another option for hybrid applications is to whiteList
area where Focus-Lock should act, automatically allowing other managers in other areas.
The code below will scope Focus-Lock on inside the (react)root
element, so anything jQuery can add to the body will be ignored.
<FocusLock whiteList={node => document.getElementById('root').contains(node)}>
...
</FocusLock>
Two Focus-Locks
React-Focus-Lock is expected to be a singlentone. __Use webpack or yarn resolution for force only one version of react-focus-lock used.
webpack.conf
resolve: {
alias: {
'react-focus-lock': path.resolve(path.join(__dirname, './node_modules/react-focus-lock'))
...
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've got a good article about focus management, dialogs and WAI-ARIA.
Not only for React
Uses focus-lock under the hood. It does also provide support for Vue.js and Vanilla DOM solutions
More
To create a "right" modal dialog you have to:
- manage a focus. Use this library
- block document scroll. Use react-scroll-locky.
- hide everything else from screen readers. Use aria-hidden
You may use react-focus-on to achieve everything above, assembled in the right order.
Licence
MIT