Upgrade to Pro — share decks privately, control downloads, hide ads and more …

A year with progressive web applications! #DevConMU

A year with progressive web applications! #DevConMU

About a year ago we started using Progressive web apps. The idea behind PWA is to replace native mobile apps.

In this talk, I will show you what is possible to build with PWA, what is the limitation and what we learn. And of course, you will see where PWA can be a good fit for your projects. Progressive Web Apps use modern web capabilities to deliver an app-like user experience.

They evolve from pages in browser tabs to immersive, top-level apps, maintaining the web's low friction at every moment. They are reliable, fast, engaging and delivering amazing UX to end users. And they are here!

Antonio Peric-Mazar

April 11, 2019

More Decks by Antonio Peric-Mazar

Other Decks in Programming


  1. 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
  2. UX

  3. “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
  4. 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.
  5. 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.
  6. Fast • No junky scrolling • No slow load performance

    • Measure and improve all the time • Bad connection (or no connection) is not excuse
  7. App shell model • Reliable performance that is consistently fast

    • Native-like interactions • Economical use of data
  8. 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
  9. 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
  10. 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/
  11. Checkout forms today: • Manual • Tedious • Slow •

    N-taps http://www.alyssatucker.com/improving-hollars-ios-checkout-process/
  12. Autofill - step forward • Autocomplete attributes • 30% faster

    • Automatic • Simple • Slow • n-taps http://www.alyssatucker.com/improving-hollars-ios-checkout-process/
  13. Web Payment API! • Automatic • Simple • Fast •

    1-tap • Supportes payment gatway,
 or some applications payment 
 (Google Pay) https://paymentrequest.show/images/pr-woocommerce.gif
  14. More APIs • Media Session • Media Capture API •

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

    Casting support • Web bluetooth • Web Share
  16. 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
  17. 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.
  18. 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
  19. 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.
  20. 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
  21. 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); }); }); }
  22. 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
  23. On install - as a dependency self.addEventListener('install', function(event) { event.waitUntil(

    caches.open('mysite-static-v3').then(function(cache) { return cache.addAll([ '/css/whatever-v3.css', '/css/imgs/sprites-v6.png', '/css/fonts/whatever-v8.woff', '/js/all-min-v4.js' // etc ]); }) ); });
  24. On install - not as a dependency self.addEventListener('install', function(event) {

    event.waitUntil( caches.open('mygame-core-v1').then(function(cache) { cache.addAll( // levels 11-20 ); return cache.addAll( // core assets & levels 1-10 ); }) ); });
  25. 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.
  26. self.addEventListener('activate', function(event) { event.waitUntil( caches.keys().then(function(cacheNames) { return Promise.all( cacheNames.filter(function(cacheName) {

    // Return true if you want to remove this cache, // but remember that caches are shared across // the whole origin }).map(function(cacheName) { return caches.delete(cacheName); }) ); }) ); }); On Activate
  27. // 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); }); }); });
  28. 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; }); }); }) ); });
  29. State-while-revalidate self.addEventListener('fetch', function(event) { event.respondWith( caches.open('mysite-dynamic').then(function(cache) { return cache.match(event.request).then(function(response) {

    var fetchPromise = fetch(event.request).then(function(networkResponse) { cache.put(event.request, networkResponse.clone()); return networkResponse; }) return response || fetchPromise; }) }) ); });
  30. 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
  31. 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)); });
  32. Cache & network race // Promise.race is no good to

    us because it rejects if // a promise rejects before fulfilling. Let's make a proper // race function: function promiseAny(promises) { return new Promise((resolve, reject) => { // make sure promises are all promises promises = promises.map(p => Promise.resolve(p)); // resolve this promise as soon as one resolves promises.forEach(p => p.then(resolve)); // reject if all promises reject promises.reduce((a, b) => a.catch(() => b)) .catch(() => reject(Error("All failed"))); }); }; self.addEventListener('fetch', function(event) { event.respondWith( promiseAny([ caches.match(event.request), fetch(event.request) ])
  33. Cache, than Network var 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);
  34. 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; }); }) ); });
  35. Generic fallback self.addEventListener('fetch', function(event) { event.respondWith( // Try the cache

    caches.match(event.request).then(function(response) { // Fall back to network return response || fetch(event.request); }).catch(function() { // If both fail, show a generic fallback: return caches.match('/offline.html'); // However, in reality you'd have many different // fallbacks, depending on URL & headers. // Eg, a fallback silhouette image for avatars. }) ); });
  36. 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
  37. Your goal is to provide a good experience that lessens

    the impact of changes in connectivity
  38. 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
  39. What makes good notification • Timely - I feel I

    need and it matters now • Precise - specific info, what happens • Personal - make it personal
  40. 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/'); } });
  41. 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" } ] }
  42. 65% increase in page per session 75% increase in Tweets

 20% decrease in bounce rate Twitter Lite
  43. 76% higher conversation across browsers 4x higher interaction rate from

    Add to screen Increased usage of native apps also Alibaba
  44. 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