Vue component to trap the focus within a DOM element

by Vue.js Examples

focus-trap-vue

Vue component to trap the focus within a DOM element.

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Installation

npm install focus-trap focus-trap-vue

Usage

This library exports one single named export FocusTrap and requires
focus-trap as a peer
dependency. So you can locally import the component or declare it globally:

import { FocusTrap } from 'focus-trap-vue'

Vue.component('FocusTrap', FocusTrap)

FocusTrap can be controlled in three different ways:

  • by using the active Boolean prop
  • by using v-model (uses the active prop)
  • by calling the activate/deactivate method on the component

The recommended approach is using v-model and it should contain one single child:

<focus-trap v-model="isActive">
  <modal-dialog tabindex="-1">
    <p>
      Do you accept the cookies?
    </p>
    <button @click="acceptCookies">Yes</button>
    <button @click="isActive = false">No</button>
  </modal-dialog>
</focus-trap>

When isActive becomes true, it activates the focus trap. By default it sets
the focus to its child, so make sure the element is a focusable element. If it's
not you wil need to give it the tabindex="-1" attribute. You can also
customize the initial element focused. This element should be an element that
the user can interact with. For example, an input. It's a good practice to
always focus an interactable element instead of the modal container:

<focus-trap v-model="isActive" :initial-focus="() => $refs.nameInput">
  <modal-dialog>
    <p>
      What name do you want to use?
    </p>
    <form @submit.prevent="setName">
      <label>
        New Name
        <input ref="nameInput" />
      </label>
      <button>Change name</button>
    </form>
  </modal-dialog>
</focus-trap>

Props

FocusTrap also accepts other props:

  • escapeDeactivates: boolean
  • returnFocusOnDeactivate: boolean
  • allowOutsideClick: boolean
  • initialFocus: string | (() => Element) Selector or function returning an Element
  • fallbackFocus: string | (() => Element) Selector or function returning an
    Element

Please, refer to
focus-trap
documentation to know what they do.

Events

FocusTrap emits 2 events. They are in-sync with the prop active

  • activate: Whenever the trap activates
  • deactive: Whenever the trap deactivates (note it can also be deactivated by
    pressing Esc or clicking outside)

Methods

FocusTrap can be used without v-model. In that case, you will use the
methods and probably need to initialize the trap as deactivated, otherwise,
the focus will start as active:

<button @click="() => $refs.focusTrap.activate()">Show the modal</button>

<focus-trap :active="false" ref="focusTrap">
  <modal-dialog>
    <p>Hello there!</p>
    <button @click="() => $refs.focusTrap.deactivate()">Okay...</button>
  </modal-dialog>
</focus-trap>

Note the use of arrow functions, this is necessary because we are accessing
$refs which are unset on first render.

GitHub