IntersectionObserver

The IntersectionObserver (opens new window).

State

The useIntersectionObserver function exposes the following reactive state:

import { useIntersectionObserver } from "vue-composable";

const { supported, elements, isIntersecting } = useIntersectionObserver(
  options
);

State	Type	Description
supported	Boolean	Is supported
elements	Ref<IntersectionObserverEntry[]>	IntersectionObserverEntry (opens new window)
isIntersecting	Ref<Boolean?	Returns true if all observed elements are intersection

Methods

The useIntersectionObserver function exposes the following methods:

import { useIntersectionObserver } from "vue-composable";

const { observe, unobserve, disconnect, debug } = useIntersectionObserver();

Signature	Description
observe(Element)	Starts observing Element
unobserve(Element	Stops observing Element
disconnect()	IntersectionObserver.disconnect (opens new window)

Example

Visible: false

Scroll down

Hide me

Scroll up

Code

<template>
  <div>
    Visible: {{ isIntersecting }}

    <p>Scroll down</p>
    <div style="height:500px" />

    <div ref="el" style="background:lightgreen">
      Hide me
    </div>

    <p>Scroll up</p>
  </div>
</template>

<script>
import { ref, watch, reactive } from "@vue/composition-api";
import { useIntersectionObserver } from "vue-composable";

export default {
  name: "intersection-observer-example",
  setup() {
    const el = ref(null);
    const o = useIntersectionObserver(el);
    return {
      ...o,
      el
    };
  }
};
</script>