SW Precache Webpack Plugin

SWPrecacheWebpackPlugin is a webpack plugin for using service workers to cache your external project dependencies. It will generate a service worker file using sw-precache and add it to your build directory.

Install

npm install --save-dev sw-precache-webpack-plugin

Basic Usage

var path = require('path');
var SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin');


module.exports = {
  context: __dirname,

  entry: {
    main: path.resolve(__dirname, 'src/index'),
  },

  output: {
    path: path.resolve(__dirname, 'src/bundles/'),
    filename: '[name]-[hash].js',
  },

  plugins: [
    new SWPrecacheWebpackPlugin(
      {
        cacheId: 'my-project-name',
        filename: 'my-service-worker.js',
        maximumFileSizeToCacheInBytes: 4194304,
        runtimeCaching: [{
          handler: 'cacheFirst',
          urlPattern: /[.]mp3$/,
        }],
      }
    ),
  ]
}

This will generate a new service worker at src/bundles/my-service-worker.js. Then you would just register it in your application:

(function() {
  if('serviceWorker' in navigator) {
    navigator.serviceWorker.register('/my-service-worker.js');
  }
})();

Another example of registering a service worker is provided by GoogleChrome/sw-precache

Configuration

You can pass a hash of configuration options to SWPrecacheWebpackPlugin:

plugin options:

• filename: [String] - Service worker filename, default is service-worker.js
• filepath: [String] - Service worker path and name, default is to use webpack.output.path + options.filename.
• staticFileGlobsIgnorePatterns: [RegExp] - Define an optional array of regex patterns to filter out of staticFileGlobs (see below)

sw-precache options:

• cacheId: [String] - Not required but you should include this, it will give your service worker cache a unique name
• directoryIndex: [String]
• dynamicUrlToDependencies: [Object<String,Array<String>]
• handleFetch: [boolean]
• ignoreUrlParametersMatching: [Array<Regex>]
• importScripts: [Array<String>] - Add [hash] if you want to import a file generated with webpack [hash] ex. ['dist/some-[hash].js']
• logger: [function]
• maximumFileSizeToCacheInBytes: [Number]
• navigateFallbackWhitelist: [Array<RegExp>]
• replacePrefix: [String]
• runtimeCaching: [Array<Object>]
• staticFileGlobs: [Array<String>] - Omit this to allow the plugin to cache all your bundles' emitted assets.
• stripPrefix: [String] - Omit this to use your webpack config's output.path + '/' for stripping prefixes.
• templateFilePath: [String]
• verbose: [boolean]

Note that all configuration options are optional. SWPrecacheWebpackPlugin will by default use all your assets emitted by webpack's compiler for the staticFileGlobs parameter and your webpack config's output.path + '/' as the stripPrefix parameter (see #4).

Here's an example using one option from sw-precache (cacheId) with one option from SWPrecacheWebpackPlugin (filename) in a configuration hash:

plugins: [
  new SWPrecacheWebpackPlugin(
    {
      cacheId: "my-project-name",
      filename: "my-project-service-worker.js",
    }
  ),
]

Examples

See the examples documentation

Webpack Dev Server Support

Currently SWPrecacheWebpackPlugin will not work with Webpack Dev Server. If you wish to test the service worker locally, you can use simple a node server see example project or python SimpleHTTPServer from your build directory. I would suggest pointing your node server to a different port than your usual local development port and keeping the precache service worker out of your local configuration (example).

Contributing

Install node dependencies:

  $ npm install

Add unit tests for your new feature in ./test/plugin.spec.js

Testing

Tests are located in ./test

Run tests:

  $ npm t