headlessui/packages/@headlessui-vue/src/components/transitions/README.md

Transition

The Transition component lets you add enter/leave transitions to conditionally rendered elements, using CSS classes to control the actual transition styles in the different stages of the transition.

• Installation
• Basic example
• Showing and hiding content
• Animating transitions
• Co-ordinating multiple transitions
• Transitioning on initial mount
• Component API

Installation

# npm
npm install @headlessui/vue

# Yarn
yarn add @headlessui/vue

Basic example

The Transition accepts a show prop that controls whether the children should be shown or hidden, and a set of lifecycle props (like enterFrom, and leaveTo) that let you add CSS classes at specific phases of a transition.

<template>
  <button @click="open = !open">Toggle</button>
  <TransitionRoot
    :show="open"
    enter="transition-opacity duration-75"
    enterFrom="opacity-0"
    enterTo="opacity-100"
    leave="transition-opacity duration-150"
    leaveFrom="opacity-100"
    leaveTo="opacity-0"
  >
    I will fade in and out
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

Showing and hiding content

Wrap the content that should be conditionally rendered in a <Transition> component, and use the show prop to control whether the content should be visible or hidden.

<template>
  <button @click="open = !open">Toggle</button>
  <TransitionRoot :show="open">
    I will fade in and out
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

The Transition component will render a div by default, but you can use the as prop to render a different element instead if needed. Any other HTML attributes (like className) can be added directly to the Transition the same way they would be to regular elements.

<template>
  <button @click="open = !open">Toggle</button>
  <TransitionRoot :show="open" as="a" href="/my-url" class="font-bold">
    I will fade in and out
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

Animating transitions

By default, a Transition will enter and leave instantly, which is probably not what you're looking for if you're using this library.

To animate your enter/leave transitions, add classes that provide the styling for each phase of the transitions using these props:

• enter: Applied the entire time an element is entering. Usually you define your duration and what properties you want to transition here, for example transition-opacity duration-75.
• enterFrom: The starting point to enter from, for example opacity-0 if something should fade in.
• enterTo: The ending point to enter to, for example opacity-100 after fading in.
• leave: Applied the entire time an element is leaving. Usually you define your duration and what properties you want to transition here, for example transition-opacity duration-75.
• leaveFrom: The starting point to leave from, for example opacity-100 if something should fade out.
• leaveTo: The ending point to leave to, for example opacity-0 after fading out.

Here's an example:

<template>
  <button @click="open = !open">Toggle</button>
  <TransitionRoot
    :show="open"
    enter="transition-opacity duration-75"
    enterFrom="opacity-0"
    enterTo="opacity-100"
    leave="transition-opacity duration-150"
    leaveFrom="opacity-100"
    leaveTo="opacity-0"
  >
    I will fade in and out
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

In this example, the transitioning element will take 75ms to enter (that's the duration-75 class), and will transition the opacity property during that time (that's transition-opacity).

It will start completely transparent before entering (that's opacity-0 in the enterFrom phase), and fade in to completely opaque (opacity-100) when finished (that's the enterTo phase).

When the element is being removed (the leave phase), it will transition the opacity property, and spend 150ms doing it (transition-opacity duration-150).

It will start as completely opaque (the opacity-100 in the leaveFrom phase), and finish as completely transparent (the opacity-0 in the leaveTo phase).

All of these props are optional, and will default to just an empty string.

Co-ordinating multiple transitions

Sometimes you need to transition multiple elements with different animations but all based on the same state. For example, say the user clicks a button to open a sidebar that slides over the screen, and you also need to fade-in a background overlay at the same time.

You can do this by wrapping the related elements with a parent Transition component, and wrapping each child that needs its own transition styles with a TransitionChild component, which will automatically communicate with the parent Transition and inherit the parent's show state.

<template>
  <TransitionRoot :show="open">
    <!-- Background overlay -->
    <TransitionChild
      enter="transition-opacity ease-linear duration-300"
      enterFrom="opacity-0"
      enterTo="opacity-100"
      leave="transition-opacity ease-linear duration-300"
      leaveFrom="opacity-100"
      leaveTo="opacity-0"
    >
      <!-- ... -->
    </TransitionChild>

    <!-- Sliding sidebar -->
    <TransitionChild
      enter="transition ease-in-out duration-300 transform"
      enterFrom="-translate-x-full"
      enterTo="translate-x-0"
      leave="transition ease-in-out duration-300 transform"
      leaveFrom="translate-x-0"
      leaveTo="-translate-x-full"
    >
      <!-- ... -->
    </TransitionChild>
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition, TransitionChild } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition, TransitionChild },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

The TransitionChild component has the exact same API as the Transition component, but with no show prop, since the show value is controlled by the parent.

Parent Transition components will always automatically wait for all children to finish transitioning before unmounting, so you don't need to manage any of that timing yourself.

Transitioning on initial mount

If you want an element to transition the very first time it's rendered, set the appear prop to true.

This is useful if you want something to transition in on initial page load, or when its parent is conditionally rendered.

<template>
  <TransitionRoot
    :show="open"
    enter="transition-opacity duration-75"
    enterFrom="opacity-0"
    enterTo="opacity-100"
    leave="transition-opacity duration-150"
    leaveFrom="opacity-100"
    leaveTo="opacity-0"
  >
    <!-- Your content goes here -->
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

Component API

Transition

<template>
  <TransitionRoot
    :show="open"
    :appear="true"
    enter="transition-opacity duration-75"
    enterFrom="opacity-0"
    enterTo="opacity-100"
    leave="transition-opacity duration-150"
    leaveFrom="opacity-100"
    leaveTo="opacity-0"
  >
    <!-- Your content goes here -->
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

Props

Prop	Type	Default	Description
show	Boolean	-	Whether the children should be shown or hidden.
as	String | Component	div	The element or component to render in place of the Transition itself.
appear	Boolean	false	Whether the transition should run on initial mount.
unmount	Boolean	true	Whether the element should be unmounted or hidden based on the show state.
enter	String	''	Classes to add to the transitioning element during the entire enter phase.
enterFrom	String	''	Classes to add to the transitioning element before the enter phase starts.
enterTo	String	''	Classes to add to the transitioning element immediately after the enter phase starts.
leave	String	''	Classes to add to the transitioning element during the entire leave phase.
leaveFrom	String	''	Classes to add to the transitioning element before the leave phase starts.
leaveTo	String	''	Classes to add to the transitioning element immediately after the leave phase starts.

Events

Event	Description
beforeEnter	Callback which is called before we start the enter transition.
afterEnter	Callback which is called after we finished the enter transition.
beforeLeave	Callback which is called before we start the leave transition.
afterLeave	Callback which is called after we finished the leave transition.

Render prop object

• None

TransitionChild

<template>
  <TransitionRoot :show="open">
    <TransitionChild
      enter="transition-opacity ease-linear duration-300"
      enterFrom="opacity-0"
      enterTo="opacity-100"
      leave="transition-opacity ease-linear duration-300"
      leaveFrom="opacity-100"
      leaveTo="opacity-0"
    >
      <!-- Your content goes here -->
    </TransitionChild>
  </TransitionRoot>
</template>

<script>
import { ref } from 'vue'
import { Transition, TransitionChild } from '@headlessui/vue'

export default {
  components: { TranitionRoot: Transition, TransitionChild },
  setup() {
    let open = ref(false)
    return { open }
  },
}
</script>

Props

Prop	Type	Default	Description
as	String | Component	div	The element or component to render in place of the TransitionChild itself.
appear	Boolean	false	Whether the transition should run on initial mount.
unmount	Boolean	true	Whether the element should be unmounted or hidden based on the show state.
enter	String	''	Classes to add to the transitioning element during the entire enter phase.
enterFrom	String	''	Classes to add to the transitioning element before the enter phase starts.
enterTo	String	''	Classes to add to the transitioning element immediately after the enter phase starts.
leave	String	''	Classes to add to the transitioning element during the entire leave phase.
leaveFrom	String	''	Classes to add to the transitioning element before the leave phase starts.
leaveTo	String	''	Classes to add to the transitioning element immediately after the leave phase starts.

Events

Event	Description
beforeEnter	Callback which is called before we start the enter transition.
afterEnter	Callback which is called after we finished the enter transition.
beforeLeave	Callback which is called before we start the leave transition.
afterLeave	Callback which is called after we finished the leave transition.

Render prop object

• None