Workbox BackgroundSync Message

This plugin extends workbox backgroundsync plugin with catching response messages and send them to the UI thread. It is useful when you need the response from the API server after background-sync was successful.

This class is made for @vue/cli-plugin-pwa what uses workbox 4.3.1. At the time of writing of this plugin, the current workbox version is 6.0.2 but this functionality is still missing.

Workbox backgroundSync is amazing https://developers.google.com/web/tools/workbox/modules/workbox-background-sync but I think in most cases we need the response from the API when the backgroundSync is finished.

Pull requests are welcome

Usage

There are a few things should be in place to get the response

1. Install

npm i @rrd/workbox-backgroundsync-message

Copy the plugin file to src

cp node_modules/@rrd/workbox-backgroundsync-message/backgroundSyncMessagePlugin.js src/

First copy the plugin file from your node_modules folder to your src folder. As service workers have their own scope it should be done manually, it can not be imported. This step should be done again on updating this plugin. (Maybe a postinstall script in package.json could solve this).

Alternatively you can just copy the backgroundSyncMessagePlugin.js file from the repo to your src folder.

2. Postbuild script

Add this new line to your package.json file at the scripts block. This will copy the plugin from src to dist after each build.

  "postbuild": "cp src/backgroundSyncMessagePlugin.js dist/",

3. /vue.config.js

module.exports = {
  pwa: {
    workboxPluginMode: "InjectManifest",
    workboxOptions: {
      swSrc: './src/sw.js',
    }
  }
}

4. /src/sw.js

importScripts('/backgroundSyncMessagePlugin.js')

// your workbox service worker stuff here

// and use this plugin for any of your routes
workbox.routing.registerRoute(
  'https://your.apiurl.here',
  new workbox.strategies.NetworkOnly({
    plugins: [
      new BackgroundSyncMessagePlugin('your-choosen-queue-name', { maxRetentionTime: 1440 })
    ]
  }),
  'POST'
)

5. At any of your components

created(){
    navigator.serviceWorker.addEventListener('message', event => {
      // do whatever you want with the response
      console.warn('message got in this component', event.data);
    });
  },