useIntersectionObserver

Demo

Scroll me down!

Hello world!

Element outside the viewport

Usage

html

<div ref="target">
  <h1>Hello world</h1>
</div>

<div ref="target">
  <h1>Hello world</h1>
</div>

import { ref } from 'vue'
import { useIntersectionObserver } from '@vueuse/core'

export default {
  setup() {
    const target = ref(null)
    const targetIsVisible = ref(false)

    const { stop } = useIntersectionObserver(
      target,
      ([{ isIntersecting }], observerElement) => {
        targetIsVisible.value = isIntersecting
      },
    )

    return {
      target,
      targetIsVisible,
    }
  },
}

import { ref } from 'vue'
import { useIntersectionObserver } from '@vueuse/core'

export default {
  setup() {
    const target = ref(null)
    const targetIsVisible = ref(false)

    const { stop } = useIntersectionObserver(
      target,
      ([{ isIntersecting }], observerElement) => {
        targetIsVisible.value = isIntersecting
      },
    )

    return {
      target,
      targetIsVisible,
    }
  },
}

Directive Usage

This function also provides a directive version via the @vueuse/components package. Learn more about the usage.

html

<script setup lang="ts">
import { ref } from 'vue'
import { vIntersectionObserver } from '@vueuse/components'

const root = ref(null)

const isVisible = ref(false)

function onIntersectionObserver([{ isIntersecting }]) {
  isVisible.value = isIntersecting
}

</script>

<template>
  <div>
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="onIntersectionObserver">
      <p>Hello world!</p>
    </div>
  </div>

  <!-- with options -->
  <div ref="root">
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="[onIntersectionObserver, { root }]">
      <p>Hello world!</p>
    </div>
  </div>
</template>

<script setup lang="ts">
import { ref } from 'vue'
import { vIntersectionObserver } from '@vueuse/components'

const root = ref(null)

const isVisible = ref(false)

function onIntersectionObserver([{ isIntersecting }]) {
  isVisible.value = isIntersecting
}

</script>

<template>
  <div>
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="onIntersectionObserver">
      <p>Hello world!</p>
    </div>
  </div>

  <!-- with options -->
  <div ref="root">
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="[onIntersectionObserver, { root }]">
      <p>Hello world!</p>
    </div>
  </div>
</template>

IntersectionObserver MDN

Type Declarations

typescript

export interface UseIntersectionObserverOptions extends ConfigurableWindow {
  /**
   * The Element or Document whose bounds are used as the bounding box when testing for intersection.
   */
  root?: MaybeElementRef
  /**
   * A string which specifies a set of offsets to add to the root's bounding_box when calculating intersections.
   */
  rootMargin?: string
  /**
   * Either a single number or an array of numbers between 0.0 and 1.
   */
  threshold?: number | number[]
}
/**
 * Detects that a target element's visibility.
 *
 * @see https://vueuse.org/useIntersectionObserver
 * @param target
 * @param callback
 * @param options
 */
export declare function useIntersectionObserver(
  target: MaybeElementRef,
  callback: IntersectionObserverCallback,
  options?: UseIntersectionObserverOptions
): {
  isSupported: Ref<boolean>
  stop: () => void
}
export type UseIntersectionObserverReturn = ReturnType<
  typeof useIntersectionObserver
>

export interface UseIntersectionObserverOptions extends ConfigurableWindow {
  /**
   * The Element or Document whose bounds are used as the bounding box when testing for intersection.
   */
  root?: MaybeElementRef
  /**
   * A string which specifies a set of offsets to add to the root's bounding_box when calculating intersections.
   */
  rootMargin?: string
  /**
   * Either a single number or an array of numbers between 0.0 and 1.
   */
  threshold?: number | number[]
}
/**
 * Detects that a target element's visibility.
 *
 * @see https://vueuse.org/useIntersectionObserver
 * @param target
 * @param callback
 * @param options
 */
export declare function useIntersectionObserver(
  target: MaybeElementRef,
  callback: IntersectionObserverCallback,
  options?: UseIntersectionObserverOptions
): {
  isSupported: Ref<boolean>
  stop: () => void
}
export type UseIntersectionObserverReturn = ReturnType<
  typeof useIntersectionObserver
>