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Add comprehensive reference documentation for: - Vitest: environments, projects/workspaces, type testing, vi utilities - Pinia: HMR, Nuxt integration, SSR setup - Vue: built-in components (Transition, Teleport, Suspense, KeepAlive) and advanced directives
2.8 KiB
2.8 KiB
category
| category |
|---|
| Elements |
useElementVisibility
Tracks the visibility of an element within the viewport.
Usage
<script setup lang="ts">
import { useElementVisibility } from '@vueuse/core'
import { useTemplateRef } from 'vue'
const target = useTemplateRef('target')
const targetIsVisible = useElementVisibility(target)
</script>
<template>
<div ref="target">
<h1>Hello world</h1>
</div>
</template>
rootMargin
If you wish to trigger your callback sooner before the element is fully visible, you can use
the rootMargin option (See MDN IntersectionObserver/rootMargin).
import { useElementVisibility } from '@vueuse/core'
// ---cut---
const targetIsVisible = useElementVisibility(target, {
rootMargin: '0px 0px 100px 0px',
})
threshold
If you want to control the percentage of the visibility required to update the value, you can use the threshold option (See MDN IntersectionObserver/threshold).
const targetIsVisible = useElementVisibility(target, {
threshold: 1.0, // 100% visible
})
Component Usage
<template>
<UseElementVisibility v-slot="{ isVisible }">
Is Visible: {{ isVisible }}
</UseElementVisibility>
</template>
Directive Usage
<script setup lang="ts">
import { vElementVisibility } from '@vueuse/components'
import { shallowRef, useTemplateRef } from 'vue'
const target = useTemplateRef('target')
const isVisible = shallowRef(false)
function onElementVisibility(state) {
isVisible.value = state
}
</script>
<template>
<div v-element-visibility="onElementVisibility">
{{ isVisible ? 'inside' : 'outside' }}
</div>
<!-- with options -->
<div ref="target">
<div v-element-visibility="[onElementVisibility, { scrollTarget: target }]">
{{ isVisible ? 'inside' : 'outside' }}
</div>
</div>
</template>
Type Declarations
export interface UseElementVisibilityOptions
extends
ConfigurableWindow,
Pick<UseIntersectionObserverOptions, "rootMargin" | "threshold"> {
/**
* Initial value.
*
* @default false
*/
initialValue?: boolean
/**
* The element that is used as the viewport for checking visibility of the target.
*/
scrollTarget?: UseIntersectionObserverOptions["root"]
/**
* Stop tracking when element visibility changes for the first time
*
* @default false
*/
once?: boolean
}
export type UseElementVisibilityReturn = ShallowRef<boolean>
/**
* Tracks the visibility of an element within the viewport.
*
* @see https://vueuse.org/useElementVisibility
*/
export declare function useElementVisibility(
element: MaybeComputedElementRef,
options?: UseElementVisibilityOptions,
): UseElementVisibilityReturn