The document discusses Progressive Web Apps (PWAs), which utilize modern web capabilities to deliver an app-like user experience across various devices while ensuring speed, reliability, and user engagement. It outlines key features of PWAs, such as offline functionality through service workers, installation without an app store, and enhanced user interaction via push notifications. Additionally, it emphasizes the importance of reliable performance and optimal UX design to accommodate varying network conditions.

1. Progressive Web Apps are
here!
Antonio Perić-Mažar, Locastic
27.10.2018., #sfcampua

3. Antonio Perić-Mažar
CEO @ Locastic
Co-Founder @ Blockada
antonio@locastic.com
@antonioperic

4. Locastic
• We help clients create amazing web and mobile apps (since 2011)
• mobile development
• web development
• UX/UI
• Training and Consulting
• Shift Conference, Symfony Croatia
• www.locastic.com t: @locastic

6. Not a Symfony talk!

7. [Mobile] User Experience
on Web

14. And trust me… you will never had enough cheese

15. “I don't care how many kick-ass Visio architecture diagrams
you have; as far as the user is concerned, the UI is the
application. I know UI US HARD, but you have to build an
impressive UI if you want to be taken seriously. Give your UI
the high priority it deserves.”
Jeff Atwood, Coding Horror blog

17. Capebility
Reach

18. “A Progressive Web App uses
modern web capabilities to deliver
an app-like user experience.”

19. “A Progressive Web App uses
modern web capabilities to deliver
an app-like user experience.”

20. PWA is:
• Progressive - Works for every user, regardless of browser choice because it's
built with progressive enhancement as a core tenet.
• Responsive - Fits any form factor: desktop, mobile, tablet, or whatever is next.
• Connectivity independent - Enhanced with service workers to work offline or
on low-quality networks.
• App-like - Feels like an app, because the app shell model separates the
application functionality from application content .
• Fresh - Always up-to-date thanks to the service worker update process.

21. PWA is:
• Safe - Served via HTTPS to prevent snooping and to ensure content hasn't been
tampered with.
• Discoverable - Is identifiable as an "application" thanks to W3C manifest and
service worker registration scope, allowing search engines to find it.
• Re-engageable - Makes re-engagement easy through features like push
notifications.
• Installable - Allows users to add apps they find most useful to their home
screen without the hassle of an app store.
• Linkable - Easily share the application via URL, does not require complex
installation.

23. Fast Integrated
Reliable Engaging
4
things to focus on

24. Fast Integrated
Reliable Engaging

25. Fast
• No junky scrolling
• No slow load performance
• Measure and improve all the time
• Bad connection (or no connection) is not excuse

26. 53%
of users abandon
sites that take longer
than 3 seconds to load

27. https://cloudfour.com/thinks/ios-doesnt-support-progressive-web-apps-so-what/

29. App shell model
• Reliable performance that is consistently fast
• Native-like interactions
• Economical use of data

30. Fast Integrated
Reliable Engaging

31. Integrated
• User should not reach browser to reach your app
• They should be able to interact same as with any other
app on their device
• They expect to have all possibilities as other apps
• Users should be able to start app from their home
screen

32. https://www.mobigyaan.com/android-8-0-oreo-vs-ios-11-which-is-better

35. https://techcrunch.com/2017/08/25/majority-of-u-s-consumers-still-download-zero-apps-per-month-says-comscore/

36. https://techcrunch.com/2017/08/25/majority-of-u-s-consumers-still-download-zero-apps-per-month-says-comscore/

37. https://www.technology.org/2017/07/28/progressive-web-apps-vs-native-which-is-better-for-your-business/

38. 80%
users intentionally moved apps
to their home screen

39. Broken experience
• Required user interaction
• Where it will start?
• Would it work offline?
https://medium.com/@saigeleslie/how-to-create-a-progressive-web-app-with-react-in-5-mins-or-less-3aae3fe98902

40. Web manifest
• Simple JSON file
• Tell browsers about your app and how it should behave once
app is ‘installed’
• Having manifest is required to show add to home screen pop-up
• Works for desktop and mobile apps (chrome)
• https://manifest-validator.appspot.com/
• https://app-manifest.firebaseapp.com/

41. {
"background_color":"#ffffff",
"description":"It's what's happening. From breaking news and entertainment, sports
and politics, to big events and everyday interests.",
"display":"standalone",
"gcm_sender_id":"49625052041",
"gcm_user_visible_only":true,
"icons":[
{
"src":"https://abs.twimg.com/responsive-web/web/ltr/icon-default.
604e2486a34a2f6e.png",
"sizes":"192x192",
"type":"image/png"
},
{
"src":"https://abs.twimg.com/responsive-web/web/ltr/icon-default.
604e2486a34a2f6e.png",
"sizes":"512x512",
"type":"image/png"
}
],
"name":"Twitter",
"share_target":{
"action":"compose/tweet",
"params":{
"title":"title",
"text":"text",
"url":"url"
}
},
"short_name":"Twitter",
"start_url":"/",
"theme_color":"#ffffff",
“scope":"/"
}

43. {
"background_color":"#ffffff",
"display":"standalone",
"icons":[
…
],
"name":"Twitter",
"short_name":"Twitter",
"start_url":"/",
"theme_color":"#ffffff",
“scope":"/"
}
<link rel="manifest" href="/manifest.json">
You can add it now to
your app

44. What are the criteria?
• The web app is not already installed
• Meets a user engagement heuristic (currently, the user
has interacted with the domain for at least 30 seconds)
• Served over HTTPS (required for service workers)
• Has registered a service worker with a fetch event
handler

45. What are the criteria?
• Includes a web app manifest that includes:
• Short name or name
• Icons must include a 192px and a 512px sized icons
• start_url
• Display must be: fullscreen, standalone, or minimal-
ui

46. What are the criteria?
• When these criteria are met, Chrome will fire a
beforeinstallprompt event that you can use to
prompt the user to install your Progressive Web App.
let deferredPrompt;
window.addEventListener('beforeinstallprompt', (e) => {
// Prevent Chrome 67 and earlier from automatically showing the prompt
e.preventDefault();
// Stash the event so it can be triggered later.
deferredPrompt = e;
});

47. What are the criteria?
btnAdd.addEventListener('click', (e) => {
// hide our user interface that shows our A2HS button
btnAdd.style.display = 'none';
// Show the prompt
deferredPrompt.prompt();
// Wait for the user to respond to the prompt
deferredPrompt.userChoice
.then((choiceResult) => {
if (choiceResult.outcome === 'accepted') {
console.log('User accepted the A2HS prompt');
} else {
console.log('User dismissed the A2HS prompt');
}
deferredPrompt = null;
});
});

48. https://ponyfoo.com/articles/progressive-app-serviceworker

49. 40%
higher interaction rate from
Home screen

51. Web Payment API!

52. 66%
of purchases on mobile are
on the web

53. 1/3
of purchases on Web are
via mobile
That means the UX
is BROKEN!

54. Checkout forms today:
• Manual
• Tedious
• Slow
• N-taps
http://www.alyssatucker.com/improving-hollars-ios-checkout-process/

55. Autofill - step forward
• Autocomplete attributes
• 30% faster
• Automatic
• Simple
• Slow
• n-taps
http://www.alyssatucker.com/improving-hollars-ios-checkout-process/

56. Web Payment API!

59. // Supported payment methods
const paymentMethods = [{
supportedMethods: 'basic-card',
data: {
supportedNetworks: [
'visa', 'mastercard', 'amex', 'discover',
'diners', 'jcb', 'unionpay'
]
}
}, {
supportedMethods: 'https://bobpay.xyz/pay',
}];
Define payment methods

60. var options = {
requestShipping: true,
requestPayerEmail: true,
requestPayerPhone: true,
requestPayerName: true,
shippingType: 'delivery'
};
var request = new PaymentRequest(paymentMethods, paymentDetails,
paymentOptions);
Setup your payment options

61. request.show().then(response => {
// [process payment]
// send to a PSP etc.
response.complete('success');
});
Show payment screen

63. { // example response
"methodName": "basic-card",
"details": {
"cardholderName": "Larry Page",
"cardNumber": "4111111111111111",
"expiryMonth": "12",
"expiryYear": "2020",
"cardSecurityCode": "111",
"billingAddress": { ... }
},
"payerName": "Larry Page",
"payerPhone": "212-555-1212",
"payerEmail": "user@example.com"
}
Payment response

64. Web Payment API!
• Automatic
• Simple
• Fast
• 1-tap
• Supportes payment gatway,
or some applications payment
(Google Pay)
https://paymentrequest.show/images/pr-woocommerce.gif

65. More APIs
• Media Session
• Media Capture API
• Casting support
• Web bluetooth
• Web Share

66. More APIs
• Media Session
• Media Capture API
• Casting support
• Web bluetooth
• Web Share

67. Remember
users expect to be able to
interact with your app in the
same way that they do all of
the other apps on their device

68. Fast Integrated
Reliable Engaging

69. Reliable
Reliability means, never showing the Downsaur

71. Reliable
• The quality of a network connection can be affected by a number of factors such as:
• Poor coverage of a provider.
• Extreme weather conditions.
• Power outages.
• Users travelling into “dead zones” such as buildings that block their network
connections.
• Travelling on a train and going through a tunnel.
• Internet connection is managed by a third party and time boxed when it will be
active or inactive like in an airport or hotel.
• Cultural practises that require limited or no internet access at specific times or days.

72. Reliable
• We need instant loading offline
• 60% of mobile connection is 2G
• Fast Application is UX
• 14 sec to load average website on 4g
• 19 sec to load average website on 3G

73. Service Workers

74. Service Workers

75. Service WorkersService Workers

76. Service Workers
• Rich offline experiences
• Background syncs
• Push notifications
• …

77. Service Workers
• Script that browser runs in background, separated
from web page
• It is Javascript worker, so it cannot access to DOM
directly
• Service worker is a programmable network proxy,
allowing you to control how network requests from
your page are handled.

78. Service Workers
• It's terminated when not in use, and restarted when
it's next needed, so you cannot rely on global state
within a service worker's onfetch and onmessage
handlers.
• Service workers make extensive use of promises
• Service worker is for second load

79. Service Workers lifecycle

80. Register a Service Worker
if ('serviceWorker' in navigator) {
window.addEventListener('load', function() {
navigator.serviceWorker.register('/sw.js').then(function(registration)
{
// Registration was successful
console.log('ServiceWorker registration successful with scope: ',
registration.scope);
}, function(err) {
// registration failed :(
console.log('ServiceWorker registration failed: ', err);
});
});
}

82. On Install
var CACHE_NAME = 'my-site-cache-v1';
var urlsToCache = [
'/',
'/styles/main.css',
'/script/main.js'
];
self.addEventListener('install', function(event) {
// Perform install steps
event.waitUntil(
caches.open(CACHE_NAME)
.then(function(cache) {
console.log('Opened cache');
return cache.addAll(urlsToCache);
})
);
});

84. Cache and return requests
self.addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
// Cache hit - return response
if (response) {
return response;
}
return fetch(event.request);
}
)
);
});

86. Service workers Events
• On install - as a dependency
• On install - not as a dependency
• On activate
• On user interaction
• On network response
• Stale-while-revalidate
• On push message
• On background-sync

87. Update Service Worker
• Update your service worker JavaScript file. When the user navigates to your
site, the browser tries to redownload the script file that defined the service
worker in the background. If there is even a byte's difference in the service
worker file compared to what it currently has, it considers it new.
• Your new service worker will be started and the install event will be fired.
• At this point the old service worker is still controlling the current pages so the
new service worker will enter a waiting state.
• When the currently open pages of your site are closed, the old service worker
will be killed and the new service worker will take control.
• Once your new service worker takes control, its activate event will be fired.

88. Update Service Worker
• self.skipWaiting()
• Skips waiting for refresh to start using new SW

89. On User Interaction

90. // on user interaction
document.querySelector('.cache-article').addEventListener('click',
function(event) {
event.preventDefault();
var id = this.dataset.articleId;
caches.open('mysite-article-' + id).then(function(cache) {
fetch('/get-article-urls?id=' + id).then(function(response) {
// /get-article-urls returns a JSON-encoded array of
// resource URLs that a given article depends on
return response.json();
}).then(function(urls) {
cache.addAll(urls);
});
});
});

91. On Network response

92. self.addEventListener('fetch', function(event) {
event.respondWith(
caches.open('mysite-dynamic').then(function(cache) {
return cache.match(event.request).then(function (response) {
return response || fetch(event.request).then(function(response) {
cache.put(event.request, response.clone());
return response;
});
});
})
);
});

93. On Background Sync

94. self.addEventListener('sync', function(event) {
if (event.id == 'update-leaderboard') {
event.waitUntil(
caches.open('mygame-dynamic').then(function(cache) {
return cache.add('/leaderboard.json');
})
);
}
});

95. SW: Serving suggestions - responding to requests
• Cache only
• Network only
• Cache, falling back to network
• Cache & network race
• Network falling back to cache
• Cache then network
• Generic fallback
• ServiceWorker-side templating

96. Cache only

97. Cache only
self.addEventListener('fetch', function(event) {
// If a match isn't found in the cache, the response
// will look like a connection error
event.respondWith(caches.match(event.request));
});

98. Network only

99. Network only
self.addEventListener('fetch', function(event) {
event.respondWith(fetch(event.request));
// or simply don't call event.respondWith, which
// will result in default browser behaviour
});

100. Cache, falling back to network

101. Cache, falling back to network
self.addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request).then(function(response) {
return response || fetch(event.request);
})
);
});

102. Network, falling back to Cache

103. Network, falling back to Cache
self.addEventListener('fetch', function(event) {
event.respondWith(
fetch(event.request).catch(function() {
return caches.match(event.request);
})
);
});

104. Cache, than Network

105. Cache, than Networkvar networkDataReceived = false;
startSpinner();
// fetch fresh data
var networkUpdate = fetch('/data.json').then(function(response) {
return response.json();
}).then(function(data) {
networkDataReceived = true;
updatePage(data);
});
// fetch cached data
caches.match('/data.json').then(function(response) {
if (!response) throw Error("No data");
return response.json();
}).then(function(data) {
// don't overwrite newer network data
if (!networkDataReceived) {
updatePage(data);
}
}).catch(function() {
// we didn't get cached data, the network is our last hope:
return networkUpdate;
}).catch(showErrorMessage).then(stopSpinner);

106. Cache, than Network
self.addEventListener('fetch', function(event) {
event.respondWith(
caches.open('mysite-dynamic').then(function(cache) {
return fetch(event.request).then(function(response) {
cache.put(event.request, response.clone());
return response;
});
})
);
});

110. Reliable conclusion
• Think how you design for the success, failure and instability of a
network connection
• Data may be expensive, so be considerate to the user
• Make sure performance is part of your design process and UX
• Try to provide offline by default if your app doesn't require much
data
• Inform users of their current state and of changes in states
• https://serviceworke.rs/ - different examples

111. Your goal is to provide a good
experience that lessens the
impact of changes in
connectivity

112. Fast Integrated
Reliable Engaging

113. Engaging
• Charming and Attractive
• Shift way how we think in patterns and designs from
web patterns to some native patterns
• Push notifications (browser doesn’t need to be
opened)
• Push Notification API

114. Engaging

115. What makes good notification
Push. Push. Back upon now. (Courtesy Enrique Iglesias)

116. What makes good notification
• Timely - I feel I need and it matters now
• Precise - specific info, what happens
• Personal - make it personal

117. What makes good notification

118. https://www.slideshare.net/SeulgiChoi4/pwa-push-notification

119. https://www.slideshare.net/SeulgiChoi4/pwa-push-notification

121. self.addEventListener('push', function(event) {
if (event.data.text() == 'new-email') {
event.waitUntil(
caches.open('mysite-dynamic').then(function(cache) {
return fetch('/inbox.json').then(function(response) {
cache.put('/inbox.json', response.clone());
return response.json();
});
}).then(function(emails) {
registration.showNotification("New email", {
body: "From " + emails[0].from.name
tag: "new-email"
});
})
);
}
});
self.addEventListener('notificationclick', function(event) {
if (event.notification.tag == 'new-email') {
// Assume that all of the resources needed to render
// /inbox/ have previously been cached, e.g. as part
// of the install handler.
new WindowClient('/inbox/');
}
});

122. Push Notifications
{
"body": "Did you make a $1,000,000 purchase at Dr. Evil...",
"icon": "images/ccard.png",
"vibrate": [200, 100, 200, 100, 200, 100, 400],
"tag": "request",
"actions": [
{ "action": "yes", "title": "Yes", "icon": "images/yes.png" },
{ "action": "no", "title": "No", "icon": "images/no.png" }
]
}

123. 43%
agrees to an app’s request to
allow push notifications

124. Credentials API!
• Removes friction from sign-in flows - Users can be
automatically signed back into a site even if their session has
expired or they saved credentials on another device.
• Allows one tap sign in with account chooser - Users can choose
an account in a native account chooser.
• Stores credentials - Your application can store either a
username and password combination or even federated account
details. These credentials can be synced across devices by the
browser.

127. Tools!

128. Lighthouse

131. Some show case!

132. 65% increase in page per session
75% increase in Tweets sent
20% decrease in bounce rate
Twitter Lite

133. 76% higher conversation across browsers
4x higher interaction rate from Add to screen
Increased usage of native apps also
Alibaba

134. 80%+ conversation
54% smaller than Android app
120% smaller than iOS app
BookMyShow

135. Cut load times from 11.91 to 4.69
seconds
90% smaller than Native Android
App
https://medium.com/@addyosmani/a-tinder-progressive-web-app-performance-
case-study-78919d98ece0
Tinder

136. Myths about PWA!

137. PWAs are only for
offline apps

138. PWAs are a mobile thing

139. PWAs are a Google-only
thing

141. PWAs are not ready yet

146. https://pwa.rocks/

149. Don’t be driven with hype,
choose the best fit for your
project

150. It is not about PWA vs Native
apps, it is about Users

151. Thank you!

152. QnA?