One of the key cornerstones of any progressive web app is that any functionality that can be available offline should be available offline. In order to do that, you need to know when a device is online or offline. If you’re using Vue.js, there is a convenient little component available that makes it really easy to toggle parts of your UI or handle events whenever the device goes online or offline. Let’s take a look.

Installation

Install v-offline in your Vue.js project.

# Yarn
$ yarn add v-offline

# or NPM
$ npm install v-offline --save

Usage

<template>
  <!-- @detected-condition fires when the connectivity status of the device changes -->
  <offline @detected-condition="handleConnectivityChange">
    <!-- Only renders when the device is online -->
    <div slot="online">
      <p>It looks like you're online! Here's all the things you can do...</p>
      ...
    </div>
    <!-- Only renders when the device is offline -->
    <div slot="offline">
      <p>You appear to be offline, that's okay, we can still do things...</p>
      ...
    </div>
  </offline>
</template>

<script>
import offline from 'v-offline';

export default {
  components: {
    offline
  },

  methods: {
    handleConnectivityChange(status) {
      console.log(status);
    }
  }
}
</script>

There’s not much else to add, that’s about all you need. Enjoy!

If you’d like functionality like this but aren’t keen on adding yet another component to your dependency list, try listening to the online and offline events on the window object in your component’s mounted handler.