PWA functionality for create-react-app

README.md

@@ -93,7 +93,8 @@ Builds the app for production to the `build` folder.<br>
 It correctly bundles React in production mode and optimizes the build for the best performance.
 
 The build is minified and the filenames include the hashes.<br>
-Your app is ready to be deployed!
+A [service worker](https://developers.google.com/web/fundamentals/getting-started/primers/service-workers) using an [offline-first caching strategy](https://developers.google.com/web/fundamentals/instant-and-offline/offline-cookbook/#cache-falling-back-to-network) is automatically generated.<br>
+Your ([progressive web](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md#making-a-progressive-web-app)) app is ready to be deployed!
 
 ## User Guide
 
@@ -151,6 +152,7 @@ Please refer to the [User Guide](https://github.com/facebookincubator/create-rea
 * Import CSS and image files directly from JavaScript.
 * Autoprefixed CSS, so you don’t need `-webkit` or other prefixes.
 * A `build` script to bundle JS, CSS, and images for production, with sourcemaps.
+* An offline-first [service worker](https://developers.google.com/web/fundamentals/getting-started/primers/service-workers) and a [web app manifest](https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/), meeting all the [Progressive Web App](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md#making-a-progressive-web-app) criteria.
 
 **The feature set is intentionally limited**. It doesn’t support advanced features such as server rendering or CSS modules. The tool is also **non-configurable** because it is hard to provide a cohesive experience and easy updates across a set of tools when the user can tweak anything.
 

packages/react-scripts/config/webpack.config.prod.js

@@ -18,6 +18,7 @@ var InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
 var url = require('url');
 var paths = require('./paths');
 var getClientEnvironment = require('./env');
+var SWPrecacheWebpackPlugin = require('sw-precache-webpack-plugin');
 
 // @remove-on-eject-begin
 // `path` is not used after eject - see https://github.com/facebookincubator/create-react-app/issues/1174
@@ -273,6 +274,12 @@ module.exports = {
     // having to parse `index.html`.
     new ManifestPlugin({
       fileName: 'asset-manifest.json'
+    }),
+    new SWPrecacheWebpackPlugin({
+      dontCacheBustUrlsMatching: /\.\w{8}\./,
+      filename: 'service-worker.js',
+      navigateFallback: publicUrl + '/index.html',
+      staticFileGlobsIgnorePatterns: [/\.map$/, /asset-manifest\.json$/]
     })
   ],
   // Some libraries import Node modules but don't use them in the browser.

packages/react-scripts/package.json

@@ -59,6 +59,7 @@
     "recursive-readdir": "2.1.0",
     "strip-ansi": "3.0.1",
     "style-loader": "0.13.1",
+    "sw-precache-webpack-plugin": "^0.9.0",
     "url-loader": "0.5.7",
     "webpack": "2.2.1",
     "webpack-dev-server": "2.3.0",

packages/react-scripts/template/README.md

@@ -1048,7 +1048,82 @@ Learn more about React Storybook:
 
 ## Making a Progressive Web App
 
-You can turn your React app into a [Progressive Web App](https://developers.google.com/web/progressive-web-apps/) by following the steps in [this repository](https://github.com/jeffposnick/create-react-pwa).
+By default, the production build is a fully functional, offline-first
+[Progressive Web App](https://developers.google.com/web/progressive-web-apps/).
+
+The [`sw-precache-webpack-plugin`](https://github.com/goldhand/sw-precache-webpack-plugin)
+is integrated into [`webpack.config.prod.js`](../config/webpack.config.prod.js),
+and it will take care of generating a service worker file that will automatically
+precache all of your local assets and keep them up to date as you deploy updates.
+The service worker will use a [cache-first strategy](https://developers.google.com/web/fundamentals/instant-and-offline/offline-cookbook/#cache-falling-back-to-network)
+for handling all requests for local assets, including the initial HTML, ensuring
+that you web app is reliably fast, even on a slow or unreliable network.
+
+It includes a [web app manifest](https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/),
+located at [`public/manifest.json`](public/manifest.json), that you might want
+to customize with metadata specific to your web application, such as its name
+and branding colors.
+
+If you would prefer not to enable service workers prior to your initial
+production deployment, then remove the call to `serviceWorkerRegistration.register()`
+from [`src/index.js`](src/index.js).
+
+If you had previously enabled service workers in your production deployment and
+have decided that you would like to disable them for all your existing users,
+you can swap out the call to `serviceWorkerRegistration.register()` in
+[`src/index.js`](src/index.js) with a call to `serviceWorkerRegistration.unregister()`.
+After the user visits a page that has `serviceWorkerRegistration.unregister()`,
+the service worker will be uninstalled.
+
+### Offline-First Considerations
+
+1. Service workers [require HTTPS](https://developers.google.com/web/fundamentals/getting-started/primers/service-workers#you_need_https),
+although to facilitate local testing, that policy
+[does not apply to `localhost`](http://stackoverflow.com/questions/34160509/options-for-testing-service-workers-via-http/34161385#34161385).
+If your production web server does not support HTTPS, then the service worker
+registration will fail, but the rest of your web app will remain functional.
+
+1. Service workers are [not currently supported](https://jakearchibald.github.io/isserviceworkerready/)
+in all web browsers. Service worker registration [won't be attempted](src/register-service-worker.js)
+on browsers that lack support.
+
+1. The service worker is only enabled in the [production environment](#Deployment),
+e.g. the output of `npm run build`. It's recommended that you do not enable an
+offline-first service worker in a development environment, as it can lead to
+frustration when previously cached assets are used and do not include the latest
+changes you've made locally.
+
+1. If possible,configure your production environment to serve the generated
+`service-worker.js` [with HTTP caching disabled](http://stackoverflow.com/questions/38843970/service-worker-javascript-update-frequency-every-24-hours).
+If that's not possible—[GitHub Pages](#github-pages), for instance, does not
+allow you to change the default 10 minute HTTP cache lifetime—then be aware
+that if you visit your production site, and then revisit again before
+`service-worker.js` has expired from your HTTP cache, you'll continue to get
+the previously cached assets from the service worker. If you have an immediate
+need to view your updated production deployment, performing a shift-refresh
+will temporarily disable the service worker and retrieve all assets from the
+network.
+
+1. Users aren't always familiar with offline-first web apps. It can be useful to
+[let the user know](https://developers.google.com/web/fundamentals/instant-and-offline/offline-ux#inform_the_user_when_the_app_is_ready_for_offline_consumption)
+when the service worker has finished populating your caches (showing a "This web
+app works offline!" message) and also let them know when the service worker has
+fetched the latest updates that will be available the next time they load the
+page (showing a "New content is available; please refresh." message). Showing
+this messages is currently left as an exercise to the developer, but as a
+starting point, you can make use of the logic included in [`src/register-service-worker.js`](src/register-service-worker.js), which
+demonstrates which service worker lifecycle events to listen for to detect each
+scenario, and which as a default, just logs appropriate messages to the
+JavaScript console.
+
+1. By default, the generated service worker file will not intercept or cache any
+cross-origin traffic, like HTTP [API requests](#integrating-with-an-api-backend),
+images, or embeds loaded from a different domain. If you would like to use a
+runtime caching strategy for those requests, you can [`eject`](#npm-run-eject)
+and then configure the
+[`runtimeCaching`](https://github.com/GoogleChrome/sw-precache#runtimecaching-arrayobject)
+option in the `SWPrecachePlugin` section of
+[`webpack.config.prod.js`](../config/webpack.config.prod.js).
 
 ## Deployment
 
@@ -1096,6 +1171,15 @@ This is because when there is a fresh page load for a `/todos/42`, the server lo
 
 Now requests to `/todos/42` will be handled correctly both in development and in production.
 
+On a production build, and in a browser that supports [service workers](https://developers.google.com/web/fundamentals/getting-started/primers/service-workers),
+the service worker will automatically handle all navigation requests, like for
+`/todos/42`, by serving the cached copy of your `index.html`. This
+service worker navigation routing can be configured or disabled by
+[`eject`ing](#npm-run-eject) and then modifying the
+[`navigateFallback`](https://github.com/GoogleChrome/sw-precache#navigatefallback-string)
+and [`navigateFallbackWhitelist`](https://github.com/GoogleChrome/sw-precache#navigatefallbackwhitelist-arrayregexp)
+options of the `SWPreachePlugin` [configuration](../config/webpack.config.prod.js).
+
 ### Building for Relative Paths
 
 By default, Create React App produces a build assuming your app is hosted at the server root.<br>

packages/react-scripts/template/public/index.html

@@ -3,6 +3,7 @@
   <head>
     <meta charset="utf-8">
     <meta name="viewport" content="width=device-width, initial-scale=1">
+    <link rel="manifest" href="%PUBLIC_URL%/manifest.json">
     <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
     <!--
       Notice the use of %PUBLIC_URL% in the tag above.

packages/react-scripts/template/public/manifest.json

@@ -0,0 +1,13 @@
+{
+  "short_name": "React App",
+  "name": "React App",
+  "icons": [
+    {
+      "src": "favicon.ico",
+      "sizes": "192x192",
+      "type": "image/png"
+    }
+  ],
+  "start_url": "./",
+  "display": "standalone"
+}

packages/react-scripts/template/src/index.js

@@ -1,9 +1,12 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
 import App from './App';
+import * as serviceWorkerRegistration from './service-worker-registration';
 import './index.css';
 
 ReactDOM.render(
   <App />,
   document.getElementById('root')
 );
+
+serviceWorkerRegistration.register();

packages/react-scripts/template/src/service-worker-registration.js

@@ -0,0 +1,38 @@
+export function register() {
+  if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
+    window.addEventListener('load', () => {
+      const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;
+      navigator.serviceWorker.register(swUrl).then(registration => {
+        registration.onupdatefound = () => {
+          const installingWorker = registration.installing;
+          installingWorker.onstatechange = () => {
+            if (installingWorker.state === 'installed') {
+              if (navigator.serviceWorker.controller) {
+                // At this point, the old content will have been purged and
+                // the fresh content will have been added to the cache.
+                // It's the perfect time to display a "New content is
+                // available; please refresh." message in your web app.
+                console.log('New content is available; please refresh.');
+              } else {
+                // At this point, everything has been precached.
+                // It's the perfect time to display a
+                // "Content is cached for offline use." message.
+                console.log('Content is cached for offline use.');
+              }
+            }
+          };
+        };
+      }).catch(error => {
+        console.error('Error during service worker registration:', error);
+      });
+    });
+  }
+}
+
+export function unregister() {
+  if ('serviceWorker' in navigator) {
+    navigator.serviceWorker.ready.then(function(registration) {
+      registration.unregister();
+    });
+  }
+}