An Introduction to Service Workers - Code Europe Warsaw

Service Workers are the biggest thing to hit the browser since XMLHttpRequest. We'll take a look at what the Service Worker can do for your app and more importantly, your users. We'll see the surprisingly small amount of code you need to get started with a Service Worker and finally we'll take a look at Progressive Web Apps and how the Service Worker will take part in a revolution for web applications.

Links:

Offline apps course on Udacity: https://www.udacity.com/course/offline-web-applications--ud899

The demo SMS app: https://github.com/philnash/sms-messages-app

HTML5Rocks intro to service worker: http://www.html5rocks.com/en/tutorials/service-worker/introduction/
Service Worker spec: https://github.com/w3c/ServiceWorker
Is Service Worker Ready Yet? https://jakearchibald.github.io/isserviceworkerready/
And resources: https://jakearchibald.github.io/isserviceworkerready/resources.html
Service Worker Cookbook: http://www.serviceworke.rs/
Addy Osmani - Offline Storage for Progressive Web Apps - https://bit.ly/cache-vs-db

Twilio Blog: Web powered SMS inbox with push notifications: https://www.twilio.com/blog/2016/02/web-powered-sms-inbox-with-service-worker-push-notifications.html
Background sync: https://developers.google.com/web/updates/2015/12/background-sync?hl=en

The Service Worker trailer: https://www.youtube.com/watch?v=QiXLaisCq10

Transcript

1. AN INTRODUCTION TO SERVICE WORKERS
2. Phil Nash @philnash http:/ /philna.sh philnash@twilio.com
4. AN INTRODUCTION TO SERVICE WORKERS
5. SERVICE WORKERS ARE SCRIPTS THAT INTERCEPT NETWORK REQUESTS
6. SO WEB DEVELOPERS CAN TREAT THE NETWORK AS AN ENHANCEMENT
7. AND PROVIDE OFFLINE EXPERIENCES FOR USERS OF WEB APPLICATIONS
9. A SLIGHTLY LONGER INTRODUCTION TO SERVICE WORKERS
10. XMLHttpRequest
11. IN THE FUTURE WE WILL WONDER HOW WE COPED WITHOUT SERVICE WORKERS
12. THE BIRTH OF THE SERVICE WORKER
13. The Application Cache CACHE MANIFEST # Version 7 CACHE: # Stylesheets /style/app.css # JavaScripts /js/app.js 01. 02. 03. 04. 05. 06. 07. 08.
14. “THE APPLICATION CACHE IS A DOUCHEBAG”
15. The Spec https:/ /w3c.github.io/ServiceWorker/
16. Browsers 40 27 44 4
17. The other browsers? preview under consideration
18. SO WHAT DOES IT REALLY DO?
19. Install it navigator.serviceWorker.register("/sw.js");
20. Install it navigator.serviceWorker.register("/sw.js", { scope: "/admin" }); 01. 02. 03.
21. Install it navigator.serviceWorker.register("/sw.js").then(function(){ console.log("Yay!"); }).catch(function(){ console.log("Boo!"); }); 01. 02. 03. 04. 05.
22. It intercepts network requests // sw.js self.addEventListener("fetch", function(event) { // do something }); 01. 02. 03. 04.
23. IT'S A PROXY THAT YOU CONTROL
24. SECURITY?
25. HTTPS
26. LOCALHOST
27. DEMO
28. WHY?
29. WEB VS NATIVE
30. Native Web Online by default O ine by default Discoverable on the web App store installation
31. Native Web O ine rst O ine by default Discoverable on the web App store installation
32. DON'T CARE FOR OFFLINE?
33. PERFORMANCE
34. FALLBACKS
36. THERE'S MORE!
37. BUT HOW?
38. AN EXAMPLE APPLICATION
40. PROGRESSIVE ENHANCEMENT
41. WHAT DO WE NEED?
42. BASE EXPERIENCE
43. STATIC ASSETS
44. OFFLINE PAGES
45. BACKGROUND SYNC
46. PUSH NOTIFICATIONS
47. BASE EXPERIENCE
48. GOOD NEWS!
49. STATIC ASSETS
50. DEMO
51. THE SERVICE WORKER LIFECYCLE
52. INSTALLING INSTALLED ACTIVATING ACTIVATED REDUNDANT
53. CACHE INVALIDATION
54. DEMO
55. navigator.serviceWorker.register("/sw.js").then(function(reg) { console.log("Yay!"); reg.addEventListener("updatefound", function(){ var worker = reg.installing reg.installing.addEventListener("statechange", function(e) { if (worker.state == "installed") { worker.postMessage({action: "update"}); } }) }); }); 01. 02. 03. 04. 05. 06. 07. 08. 09. 10. 11.
56. self.skipWaiting();
57. var sw = navigator.serviceWorker; sw.addEventListener("controllerchange", function() { window.location.reload(); }); 01. 02. 03. 04.
58. TAKE BACK CONTROL
59. OFFLINE PAGES
60. DATA VS FILES
61. “FOR URL ADDRESSABLE RESOURCES, USE THE CACHE API. FOR ALL OTHER DATA, USE INDEXEDDB”
62. http:/ /bit.ly/cache-vs-db
63. IndexedDB
64. IDB-KEYVAL LOCALFORAGE IDB DEXIE POUCHDB
65. IDB-KEYVAL LOCALFORAGE IDB DEXIE POUCHDB
66. var db = new Dexie("messageStore", { autoOpen: true }); db.version(1).stores({ messages: "++,createdAt" }); 01. 02. 03. 04. 05. 06.
67. db.transaction("w", db.messages, function() { db.messages.put({ from: FROM_NUMBER, to: TO_NUMBER, createAt: new Date(), body: "Service Workers rock " }).then(function(message){ console.log("Yay!"); }); }); 01. 02. 03. 04. 05. 06. 07. 08. 09. 10.
68. db.transaction("r", db.messages, function() { db.messages.each(function(item, cursor) { render(item); }); }); 01. 02. 03. 04. 05.
69. RENDER ON THE SERVER
71. APP SHELL
73. BOOTSTRAP FROM THE PAGE OR THE DATABASE
74. UNIVERSAL JAVASCRIPT
75. BACKGROUND SYNC
76. DEMO
77. reg.sync.register('sentMessage');
78. self.addEventListener('sync', function(event) { // do the thing }); 01. 02. 03.
79. PUSH NOTIFICATIONS
80. DEMO
81. PROGRESSIVE WEB APPS
82. Progressive Web Apps • Service Worker (+ HTTPS) • manifest.json • User engagement
83. APP INSTALL BANNERS
85. ICON ON THE HOME SCREEN
86. ENHANCEMENT
87. AN INTRODUCTION TO SERVICE WORKERS
88. SERVICE WORKERS ARE SCRIPTS THAT INTERCEPT NETWORK REQUESTS
89. SO WEB DEVELOPERS CAN TREAT THE NETWORK AS AN ENHANCEMENT
90. AND PROVIDE OFFLINE EXPERIENCES FOR USERS OF WEB APPLICATIONS
91. AND PROVIDE OFFLINE EXPERIENCES FOR USERS OF WEB APPLICATIONS
92. AND PROVIDE BETTER EXPERIENCES FOR USERS OF WEB APPLICATIONS
93. IN THE FUTURE WE WILL WONDER HOW WE COPED WITHOUT SERVICE WORKERS
94. AND IF YOU'RE NOT YET CONVINCED...
96. THANKS!
97. Thanks! @philnash http:/ /philna.sh philnash@twilio.com