adamdavidcz/vue-observe-visibility

Detect when an element is becoming visible or hidden on the page.

vue-observe-visibility

Detect when an element is becoming visible or hidden on the page.

Demo

Table of contents

• Installation
• Usage
• Example

Installation

npm install --save vue-observe-visibility

⚠️ This plugin uses the Intersection Observer API that is not supported in every browser (currently supported in Edge, Firefox and Chrome). You need to include a polyfill to make it work on incompatible browsers.

Import

import Vue from 'vue'
import VueObserveVisibility from 'vue-observe-visibility'

Vue.use(VueObserveVisibility)

Or:

import Vue from 'vue'
import { ObserveVisibility } from 'vue-observe-visibility'

Vue.directive('observe-visibility', ObserveVisibility)

Browser

<script src="vue.js"></script>
<script src="vue-observe-visibility/dist/vue-observe-visibility.min.js"></script>

The plugin should be auto-installed. If not, you can install it manually with the instructions below.

Install all the directives:

Vue.use(VueObserveVisibility)

Use specific directives:

Vue.directive('observe-visibility', VueObserveVisibility.ObserveVisibility)

Usage

The v-observe-visibility directive is very easy to use. Just pass a function as the value:

<div v-observe-visibility="visibilityChanged">

This also works on components:

<MyComponent v-observe-visibility="visibilityChanged" />

The function will be called whenever the visiblity of the element changes with the argument being a boolean (true means the element is visible on the page, false means that it is not).

The second argument is the corresponding IntersectionObserverEntry object.

visibilityChanged (isVisible, entry) {
  this.isVisible = isVisible
  console.log(entry)
}

Passing custom arguments

You can add custom argument by using an intermediate function:

<div v-observe-visibility="(isVisible, entry) => visibilityChanged(isVisible, entry, customArgument)">

Here visibilityChanged will be call with a third custom argument customArgument.

Example

<div id="app">
  <button @click="show = !show">Toggle</button>
  <label>
    <input type="checkbox" v-model="isVisible" disabled/> Is visible?
  </label>
  <div ref="test" v-show="show" v-observe-visibility="visibilityChanged">Hello world!</div>
</div>

<script>
new Vue({
  el: '#app',
  data: {
    show: true,
    isVisible: true,
  },
  methods: {
    visibilityChanged (isVisible, entry) {
      this.isVisible = isVisible
      console.log(entry)
    },
  },
})
</script>

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License

MIT