Jekyll PWA Plugin

PWA support for Jekyll

This plugin provides PWA support for Jekyll. Generate a service worker and provides precache and runtime cache with Google Workbox.

Google Workbox has already developed a series of tools. If you use Webpack or Gulp as your build tool, you can easily generate a service worker with these tools. But in my blog, I don't want to use even npm, and I want to precache recent 10 posts so that they are offline available to visitors even though these posts were never opened by visitors before. That's why I try to integrate this function in Jekyll build process.

IMPORTANT This plugin supports Workbox V5 since v5.1.4. The API of Workbox V5 has changed a lot compared to previous versions, some more powerful functions added too.

PLEASE NOTE -> you must update your service worker as described below!

This plugin has been used in my blog so that you can see the effect.

Installation

This plugin is available as a RubyGem.

Option #1

Add gem 'jekyll-pwa-plugin' to the jekyll_plugin group in your Gemfile:

source 'https://rubygems.org'

gem 'jekyll'

group :jekyll_plugins do
  gem 'jekyll-pwa-plugin'
end

Then run bundle to install the gem.

Option #2

Alternatively, you can also manually install the gem using the following command:

$ gem install jekyll-pwa-plugin

After the plugin has been installed successfully, add the following lines to your _config.yml in order to tell Jekyll to use the plugin:

plugins:
- jekyll-pwa-plugin

Getting Started

Configuration

Add the following configuration block to Jekyll's _config.yml:

pwa:
  enabled: false # Optional
  sw_src_filepath: service-worker.js # Optional
  sw_dest_filename: service-worker.js # Optional
  dest_js_directory: assets/js # Required
  precache_recent_posts_num: 5 # Optional
  precache_glob_directory: / # Optional
  precache_glob_patterns: # Optional
    - "{js,css,fonts}/**/*.{js,css,eot,svg,ttf,woff}"
    - index.html
  precache_glob_ignores: # Optional
    - sw-register.js
    - "fonts/**/*"

Parameter	Description
enabled	Determines whether a sw will be registered and written to disk. Useful to disable when you run into problems in your development environment. Default is true.
sw_src_filepath	Filepath of the source service worker. Defaults to service-worker.js
sw_dest_filename	Filename of the destination service worker. Defaults to service-worker.js
dest_js_directory	Directory of JS in _site. During the build process, some JS like workbox.js will be copied to this directory so that service worker can import them in runtime.
precache_glob_directory	Directory of precache. Workbox Config
precache_glob_patterns	Patterns of precache. Workbox Config
precache_glob_ignores	Ignores of precache. Workbox Config
precache_recent_posts_num	Number of recent posts to precache.

We handle precache and runtime cache with the help of Google Workbox v5.1.4 in service worker.

Write your own Service Worker

Create a service-worker.js in the root path of your Jekyll project. You can change this source file's path with sw_src_filepath option.

Now you can write your own Service Worker with Workbox APIs.

Here's what the service-worker.js like in my site.

// service-worker.js

// set names for both precache & runtime cache
workbox.core.setCacheNameDetails({
    prefix: 'my-blog',
    suffix: 'v1.0',
    precache: 'precache',
    runtime: 'runtime-cache'
});

// let Service Worker take control of pages ASAP
workbox.core.skipWaiting();
workbox.core.clientsClaim();

// let Workbox handle our precache list
workbox.precaching.precacheAndRoute(self.__precacheManifest);

// use `NetworkFirst` strategy for html
workbox.routing.registerRoute(
    /\.html$/,
    new workbox.strategies.NetworkFirst()
);

// use `NetworkFirst` strategy for css and js
workbox.routing.registerRoute(
    /\.(?:js|css)$/,
    new workbox.strategies.NetworkFirst()
);

// use `CacheFirst` strategy for images
workbox.routing.registerRoute(
    /assets\/(img|icons)/,
    new workbox.strategies.CacheFirst()
);

// use `StaleWhileRevalidate` third party files
workbox.routing.registerRoute(
    /^https?:\/\/cdn.staticfile.org/,
    new workbox.strategies.StaleWhileRevalidate()
);

Note

Generate a manifest.json?

This plugin won't generate a manifest.json. If you want to support this PWA feature, just add one in your root directory and Jekyll will copy it to _site.

When my site updates...

Since the service worker has precached our assets such as index.html, JS files and other static files, we should notify user when our site has something changed. When these updates happen, the service worker will go into the install stage and request the newest resources, but the user must refresh current page so that these updates can be applied. A normal solution is showing a toast with the following text: This site has changed, please refresh current page manually..

This plugin will dispatch a custom event called sw.update when the service worker has finished the update work. So in your site, you can choose to listen this event and popup a toast to remind users refreshing current page.

Contribute

Fork this repository, make your changes and then issue a pull request. If you find bugs or have new ideas that you do not want to implement yourself, file a bug report.

Copyright

Copyright (c) 2017 Pan Yuqi.

License: MIT