Progressive Web Apps

Ryan Hayes

TriJS

6/13/2017

• Buy a Mac (ok, fine, or rent one in the cloud)
• Get an Apple Developer License
• Get an Android/Google Play Developer License
• Get a Windows Store Developer License
• Write your Apple App
• Write your Android App
• React Native? Your existing stuff React/Redux?
• Xamarin?
• NativeScript?
• Cordova?

Why a web app?

• Hardware acceleration and GPU access
• It's the tech stack your team knows
• Likely already an investment/snowball
• Install base
• Wide range of devices
• Web Standars feature rate
• Browsers are Evergreen*

Graceful

Degradation

vs

Progressive Enhancement

Progressive

Web ==> Apps

App-like Web Features

• Location
• Camera/Audio
• Push Notifications
• Bluetooth, Motion, Vibration
• Payments
• Battery and Wifi
• Offline capabilities
• More...

3 PWA Requirements

• Service Workers
• Manifest
• HTTPS

Service Workers

• Evolution of AppCache Manifest
• Event-Driven worker .JS file
• Registered against origin and path
• Controls web site/page by intercepting and modifying network requests
• Runs in a worker context (separate thread)
• Can't use syncronous APIs (XHR, localStorage, etc)

Register a Service Worker

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw-test/sw.js', {scope: '/sw-test/'})
  .then(function(reg) {
    // registration worked
    console.log('Registration succeeded. Scope is ' + reg.scope);
  }).catch(function(error) {
    // registration failed
    console.log('Registration failed with ' + error);
  });
}

The Service Worker will intercept requests under scope only

PWA Manifest

<link rel="manifest" href="/manifest.json">

{
  "name": "HackerWeb",
  "short_name": "HackerWeb",
  "start_url": ".",
  "display": "standalone",
  "background_color": "#fff",
  "description": "A simply readable Hacker News app.",
  "icons": [{
    "src": "images/touch/homescreen48.png",
    "sizes": "48x48",
    "type": "image/png"
  }, {
    "src": "images/touch/homescreen72.png",
    "sizes": "72x72",
    "type": "image/png"
  }, {
    "src": "images/touch/homescreen96.png",
    "sizes": "96x96",
    "type": "image/png"
  }, {
    "src": "images/touch/homescreen144.png",
    "sizes": "144x144",
    "type": "image/png"
  }, {
    "src": "images/touch/homescreen168.png",
    "sizes": "168x168",
    "type": "image/png"
  }, {
    "src": "images/touch/homescreen192.png",
    "sizes": "192x192",
    "type": "image/png"
  }],
  "related_applications": [{
    "platform": "web"
  }, {
    "platform": "play",
    "url": "https://play.google.com/store/apps/details?id=cheeaun.hackerweb"
  }]
}

PWA App-like Features

• Granular Offline Capabilities and Control
• Unified App Manifest
• Unified Icons and chrome
• Installable (as opposed to pinnable)

Let's look at some PWAs!

Questions?

Ask!

@RyannosaurusRex on Twitter, Insta

https://ryanhayes.net

slides.com/ryanhayes