Progressive Web Apps – Hands on!

by Christian Liebel

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Progressive Web Apps Hands on! Christian Liebel @christianliebel Consultant

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Hello, it’s me. Progressive Web Apps Hands on! Christian Liebel Twitter: @christianliebel Email: christian.liebel @thinktecture.com Angular & PWA Slides: thinktecture.com /christian-liebel

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Things NOT to expect - Blueprint for PWA development - No 1:1 support Things TO EXPECT - Extensive/up-to-date insights into PWA and Angular’s PWA support - A PWA use case that works on your (comparably modern) smartphone & desktop PC - Lots of fun Hands on! Progressive Web Apps

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Progressive Web Apps Hands on! - Das PWA-Anwendungsmodell - Web App Manifest - Service Worker und Cache API - Workbox: Toolkit für PWAs - Angular-Unterstützung für PWAs - Natives Look & Feel - Migrieren & veröffentlichen - Payment Request API & Apple Pay www.rheinwerk-verlag.de/4707

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13:30–15:00 Block 1 15:00–15:30 Break 15:30–17:00 Block 2 Timetable Hands on! Progressive Web Apps

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Progressive Web Apps Hands on! https://blogs.windows.com/windowsdeveloper/2019/11/25/developing-for-the-new-category-of-dual-screen-devices-built-for-mobile-productivity/

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Progressive Web Apps Hands on! Cross-Platform Sample https://pwapraxis.liebel.io

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- The next best to-do list app - Create & read to-dos - Progressive Web App: installable - Responsive: one size fits all - Offline-first: synchronize to-do list with backend using IndexedDB & Dexie.js - No user context, sorry Demo Use Case Hands on! Progressive Web Apps

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Setup Node.js: https://nodejs.org (v12+) Angular CLI: npm i -g @angular/cli Google Chrome Editor Let’s get started Hands on! Progressive Web Apps

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ng new my-pwa --routing --style css cd my-pwa Angular CLI LAB #1 Hands on! Progressive Web Apps

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Hands on! Progressive Web Apps Responsive Linkable Discoverable Installable App-like Connectivity Independent Fresh Safe Re-engageable Progressive

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Platform Support PWA Status Quo Hands on! Progressive Web Apps 17 11.1 44 40 4.1 Chrome 40 11.3

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Responsive Progressive Web Apps Hands on! PWA Features

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One size fits all A single website layout for different screen resolutions (typically related to the screen’s width) Definition of trigger points at which the layout changes Mobile first: Create (minimal) mobile views first, then proceed with larger screens, so all devices get the best experience Key technologies: CSS3 Media Queries, CSS Flexible Box Layout, CSS Grid Layout Progressive Web Apps Hands on! Responsive

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Frameworks • Angular Material • ngx-admin • Bootstrap • Foundation • Framework7 • Custom-tailored solution Progressive Web Apps Hands on! Responsive

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ng add @angular/material Responsive LAB #2 Hands on! Progressive Web Apps

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Linkable Progressive Web Apps Hands on! PWA Features

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Reference Apps and Internal App States Goal: Directly link to applications or application states/views (deep link) Key technology for references in the World Wide Web: Hyperlinks Schema for hyperlinks: Uniform Resource Locator (URL) Solved in Angular via Routing (for views and states) Linkable Hands on! Progressive Web Apps

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ng g c todos ng g c about Linkable LAB #3 Hands on! Progressive Web Apps

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Discoverable Progressive Web Apps Hands on! PWA Features

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Distinguish Web Apps from Websites How to distinguish websites from apps? Idea: Add a file with metadata for apps only Advantage: Apps can be identified by search engines, app store providers etc. Web App Manifest Discoverable Hands on! Progressive Web Apps

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manifest.webmanifest { "short_name": "PWA Demo", "name": "My PWA Demo", "icons": [ { "src": "assets/icon-144x144.png", "sizes": "144x144", "type": "image/png" } ], "start_url": "/index.html", "display": "standalone" } Web App Manifest Title Icons Start URL Display Type Age Rating Additional Config Description Related Apps Hands on! Progressive Web Apps

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Angular CLI & PWA Schematic ng add @angular/pwa Web App Manifest LAB #4 Hands on! Progressive Web Apps

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Shortcuts (upcoming) Progressive Web Apps Hands on! Web App Manifest

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Badging API (upcoming) Progressive Web Apps Hands on! Web App Manifest

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Installable Progressive Web Apps Hands on! PWA Features

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Progressive Web Apps Hands on!

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Progressive Web Apps Hands on! Installable

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Web App Manifest Adjust the Web App Manifest (manifest.webmanifest) to your needs Run ng build --prod Test it by adding the app to your home screen Installable LAB #5 Hands on! Progressive Web Apps

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App-Like Progressive Web Apps Hands on! PWA Features

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The Power of the Modern Web Web Share API Gamepad API Payment Request API Generic Sensor API Web Bluetooth API Shape Detection API Web Notifications WebXR WebRTC WebGL Speech Synthesis Web Cryptography API IndexedDB Geolocation Canvas Media Capture and Streams Hands on! Progressive Web Apps

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Native look & feel Progressive Web Apps Hands on! App-like

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ng generate @angular/material:nav nav Progressive Web Apps Hands on! Generate Navigation LAB #6

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Connectivity Independent Part 1 Progressive Web Apps Hands on! PWA Features

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Progressive Web Apps Hands on! Offline capability with Service Worker System Website HTML/JS Cache Storage Remote storage Server Internet fetch HTTP Service Worker

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Overview Implements a “one-size-fits-all” service worker Instrumented via ngsw-config.json Restricted feature set (e.g., no communication between app and SW) • Initial caching of static content • Caching external content • Dynamic Caching • Push notifications @angular/service-worker Hands on! Progressive Web Apps

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Debugging More information on installed service workers can be found on • chrome://serviceworker- internals (Google Chrome) • about:serviceworkers (Mozilla Firefox) Progressive Web Apps Hands on! Service Worker

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Debugging Debug Service Workers using Chrome Developer Tools Progressive Web Apps Hands on! Service Worker LAB #7

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Fresh Progressive Web Apps Hands on! PWA Features

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Keep your app up-to-date The Service Worker caches a specific version of your application. If the user is online, you want to deliver the latest version of your app. When new versions become available, you might want to notify the user to update the application. Progressive Web Apps Hands on! Fresh

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@angular/service-worker Update Process Progressive Web Apps Hands on! Fresh V1 V2 V2 V1 V1 V2 Server Browser

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SwUpdate @angular/service-worker offers an SwUpdate service This service provides an available observable that fires when there’s an update. As a result, the user can be prompted to reload the website. Progressive Web Apps Hands on! Fresh

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App-like, Connectivity Independent, Fresh Check for application updates swUpdate.available.subscribe(() => …); Progressive Web Apps Hands on! Fresh LAB #8

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Connectivity Independent Part 2 Progressive Web Apps Hands on! PWA Features

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Orthogonal to Service Workers The web platform has different techniques to store arbitrary data (e.g. application state) offline: • Web Storage API (Local Storage/Session Storage—synchronous!) • Cookies (inconvenient) • IndexedDB Progressive Web Apps Hands on! Offline Capability

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IndexedDB Progressive Web Apps Hands on! Offline Capability

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IndexedDB let db; const request = indexedDB. open('TestDB'); request.onerror = err => { console.error('boo!'); }; request.onsuccess = evt => { db = request.result; }; IndexedDB API is inconvenient const db = new Dexie('TestDB'); Progressive Web Apps Hands on! Offline Capability

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Dexie.js Dexie is a minimalistic wrapper for IndexedDB Operations are based on promises instead of callbacks Near native performance (also for bulk inserts) Open-source Progressive Web Apps Hands on! Offline Capability

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IndexedDB Model { "id": "2db0d3e5-…", "title": "Angular lernen", "done": false } Install packages npm i dexie uuid --save-dev Dexie.js Table API Implement a TodoService with getAll & add methods Progressive Web Apps Hands on! Offline Capability LAB #9

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Safe Progressive Web Apps Hands on! PWA Features

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PWAs Require HTTPS! Service workers are very powerful • Can answer representatively for the server • Runs outside of the tab’s/window’s lifecycle Installation of service workers is only allowed via a secure connection Exception: localhost (for development purposes) PWAs can only be delivered via HTTPS Problem: TLS certificates are required (costs/renewal) Safe Hands on! Progressive Web Apps

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Free with automatic renewal Initiative of the Linux Foundation Automatic domain validation (Class 1) Website/Webservice has to be public available Period of validity: Comparatively short (90 days) Usage of TLS/SSL as easy as possible Plugins are available for IIS, Apache, Microsoft Azure, Plesk, … free! Let’s Encrypt Hands on! Progressive Web Apps

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Re-engageable Progressive Web Apps Hands on! PWA Features

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Get the user back with notifications Progressive Web Apps Hands on! Re-Engageable Ä Peter and 12 other people like your photo. SOCIAL NETWORK 08:12 Only today! 350 golden diamonds 💎 for $3.49!! PAY TO WIN GAME 11:19

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Push API Progressive Web Apps Hands on! Re-Engageable 17 — 44 44

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Limitations Not supported by Apple Safari on desktop and mobile - Safari Push Notfications: an alternative for the desktop platform - No information on whether or when push will be supported BUT: You can make a difference! Let the WebKit team know what you want to build with Push API: https://liebel.io/pushbug Progressive Web Apps Hands on! Re-Engageable

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Progressive Progressive Web Apps Hands on! PWA Features

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Advance with Progressive Enhancement Idea: Use available interfaces and functions of a system Users with modern, feature-rich browsers are getting better experience Apps are available on older browsers but with limited functionality Concept: Browser feature support grows over time—thereby more users can enjoy an increasing number of app features Progressive Web Apps Hands on! Progressive

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Progressive Web Apps Hands on!

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Progressive Web Apps Hands on! PWAs & App Stores (US)

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Native App Packaging Hands on! Progressive Web Apps JS HTML CSS .ipa .exe .app ELF .apk .appx Single-Page Application Cordova Electron

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Progressive Web Apps Hands on! Where’s the Web Heading to?

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Thank you for your kind attention! Christian Liebel @christianliebel [email protected]