Angular meets Project Fugu: Produktivitäts-PWAs auf Desktopniveau (Hands-on)

Progressive Web Apps sind ein plattformübergreifend einsetzbares Anwendungsmodell auf Web-Basis. Dank Project Fugu, einer Initiative der Chrome-Contributors Google, Microsoft und Intel, wird das Web um noch mächtigere Features erweitert. Damit können Entwickler endlich auch Produktivitäts-Apps wie Büro- und Bearbeitungsprogramme oder IDEs sinnvoll ins Web bringen.

In diesem Workshop zeigt Ihnen Christian Liebel von Thinktecture, wie Sie mit Angular Produktivitätsapps auf Desktopniveau entwickeln können – Zugriff auf das Dateisystem und die Zwischenablage sowie Dateizuordnungen inklusive. Und Sie können mitentwickeln: Bitte bringen Sie dazu Ihr Notebook (ohne Corporate-Proxys/Unternehmensrichtlinien) mit installiertem Google Chrome Canary, Node.js und Microsoft Visual Studio Code mit.

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1. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Christian Liebel @christianliebel Consultant
2. Hello, it’s me. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Christian Liebel Twitter: @christianliebel Email: christian.liebel @thinktecture.com Angular & PWA Slides: thinktecture.com /christian-liebel
3. 13:30–15:00 Block 1 15:00–15:30 Break 15:30–17:00 Block 2 Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Timetable
4. Things NOT to expect - Blueprint for PWA development - No AuthN/AuthZ Things To Expect - Extensive/up-to-date insights into PWA and Project Fugu - A productivity app use case that works on your desktop & smartphone - Lots of fun - Hands-on exercises Produktivitäts-PWAs auf Desktopniveau (Hands-on) Angular meets Project Fugu
5. https://paint.js.org – Productivity app – Draw images – Lots of actions & tools – Installable – Read/save files – Copy/paste images from/to clipboard – Share files to other apps – Register for file extensions Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Demo Use Case
6. (Workshop Edition) – Productivity app – Draw images – Lots of actions & tools – Installable – Read/save files – Copy/paste images from/to clipboard – Share files to other apps – Register for file extensions Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Demo Use Case
7. Setup complete? (Node.js, Google Chrome, Editor, Git) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Setup (1/3) LAB #0
8. git clone https://github.com/thinktecture/ angular-days-spring-2023-fugu.git cd angular-days-spring-2023-fugu npm i npm start -- --open Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Setup (3/3) LAB #0
9. Paint PWA Capabilities Progressive Enhancement Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Agenda
10. Paint PWA Capabilities Progressive Enhancement Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Agenda
11. Canvas – Plain bitmap for the web – Cross-platform, hardware- accelerated graphics operations – Supports different contexts (2D, 3D: WebGL, WebGL 2.0) – Supported on all evergreen browsers and on IE 9+ Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint
12. Canvas Add a canvas element to app.component.html: <canvas #canvas width="600" height="480"></canvas> Query the canvas element in app.component.ts: @ViewChild('canvas') canvas?: ElementRef<HTMLCanvasElement>; Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #1
13. Canvas 2D Context fillRect(x, y, width, height) strokeRect(x, y, width, height) beginPath() moveTo(x, y) lineTo(x, y) fill() stroke() Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint
14. Canvas 2D Context 1. Introduce a new field at the top of app.component.ts: context?: CanvasRenderingContext2D; 2. Get the 2D context in ngAfterViewInit(): const canvas = this.canvas!.nativeElement; const ctx = canvas.getContext('2d')!; this.context = ctx; 3. Prepare the canvas: ctx.fillStyle = 'white'; ctx.fillRect(0, 0, canvas.width, canvas.height); ctx.fillStyle = 'black'; Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #2
15. Low-latency Rendering Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint Web pages need to synchronize with the DOM on graphics updates causing latencies that can make drawing difficult Low-latency rendering skips syncing with the DOM with can lead to a more natural experience Supported on Chrome (Chrome OS and Windows only)
16. Low-latency Rendering Opt-in to low-latency rendering (app.js): const ctx = canvas.getContext('2d', { desynchronized: true })!; Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #3
17. Pointer Events Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint Users nowadays use different input methods, cross-platform apps should cover all of them Pointer Events offer an abstract interface to catch all input methods (pointerdown, pointermove, pointerup) event.offsetX/event.offsetY contain the pointer’s position relative to the listener
18. Pointer Events 1. In app.component.html, add event bindings for the pointer events: <canvas #canvas width="600" height="480" (pointerdown)="onPointerDown($event)" (pointermove)="onPointerMove($event)" (pointerup)="onPointerUp()" ></canvas> 2. In app.component.ts (onPointerMove()), draw the user input: this.context!.fillRect(event.offsetX, event.offsetY, 2, 2); Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #4
19. Bresenham Line Algorithm The user may move faster than the input can be processed For this case, we need to remember the previous point and interpolate the points in between The Bresenham line algorithm calculates the missing pixels between two given points Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint
20. Bresenham Line Algorithm 1. At the top of app.component.ts, a field called previousPoint to store the previous point: previousPoint?: { x: number, y: number }; 2. In onPointerDown(), set the current point as the previous point: this.previousPoint = { x: event.offsetX, y: event.offsetY }; 3. In onPointerUp(), set this.previousPoint to undefined. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #5
21. Bresenham Line Algorithm 4. In onPointerMove(), call the Bresenham line algorithm with the points: if (this.previousPoint) { const currentPoint = { x: event.offsetX, y: event.offsetY }; for (const point of this.paintService.bresenhamLine(this.previousPoint, currentPoint)) { this.context!.fillRect(point.x, point.y, 2, 2); } this.previousPoint = currentPoint; } Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #5
22. Color Selection For this demo, we will only implement the brush tool. However, we want to bring in some color. A simple method to implement a color selection is to use the HTML color-type input element that shows the native color picker: <input type="color"> Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint
23. Color Selection 1. In app.component.html, replace the content of the <nav> node with: <input type="color" #color (change)="onColorChange(color)"> 2. In app.component.ts (onColorChange()), update the context’s fill style accordingly: this.context!.fillStyle = color.value; Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Paint LAB #6
24. Paint PWA Capabilities Progressive Enhancement Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Agenda
25. Produktivitäts-PWAs auf Desktopniveau (Hands-on) Angular meets Project Fugu Responsive Linkable Discoverable Installable App-like Connectivity Independent Fresh Safe Re-engageable Progressive
26. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Web App Manifest Service Worker
27. Web App Manifest Distinguishes Web Apps from Websites JSON-based file containing metadata for apps only Apps can be identified by search engines, app store providers, etc. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
28. manifest.webmanifest { "short_name": "Paint", "name": "Paint Workshop", "theme_color": "white", "icons": [{ "src": "icon.png", "sizes": "512x512" }], "start_url": "/index.html", "display": "standalone", "shortcuts": [/* … */] } Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA Names Icons Display Mode Shortcuts Start URL Theme color (status bar/window bar)
29. Manifest Display Modes Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA browser minimal-ui standalone fullscreen
30. Manifest Icon Purposes (any) any context (e.g. app icon) monochrome different color requirements (at risk) maskable user agent masks icon as required Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA Safe Zone Windows iOS Android
31. Web App Manifest 1. Stop the npm start command, then run the following command to add PWA support to the current project: npm run ng add @angular/pwa 2. In manifest.webmanifest, a) set name and short_name to values of your choice b) change the theme_color to #000080 c) change the background_color to #808080 3. In index.html, change the theme-color to #000080. 4. Test manifest in DevTools: F12 > Application > Manifest Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA LAB #7
32. Manifest Shortcuts Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA Secondary entrypoints for your application (e.g., home screen quick actions, jump lists, …) Static definition in Web App Manifest Dynamic API may follow in the future Supported by Google Chrome for Android, macOS and Windows
33. Web App Manifest 1. In manifest.webmanifest, add (at least) the following shortcut: "shortcuts": [{ "name": "About Paint", "short_name": "About", "description": "Show information about Paint", "url": "./", "icons": [{ "src": "assets/icons/icon-512x512.png", "sizes": "512x512" }] }] 2. Test in DevTools: F12 > Application > Manifest Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA LAB #8
34. Web App Manifest – Chrome Install Criteria 1. Web App is not already installed 2. Meets a user engagement heuristic (user has interacted and clicked with origin for at least 30 seconds) 3. Includes a Web App Manifest that has short_name or name, at least a 192px and 512px icon, a start_url and a display mode of fullscreen, standalone or minimal-ui 4. Served over HTTPS 5. Has a registered service worker with a fetch event handler (subject to change!) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA https://web.dev/install-criteria/
35. Service Worker JavaScript executed in an own thread, registered by the website Acts as a controller, proxy, or interceptor Has a cache to store responses (for offline availability and performance) Can wake up even when the website is closed and perform background tasks (e.g., push notifications or sync) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
36. Service Worker Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA Service Worker Internet Website HTML/JS Cache fetch
37. NgServiceWorker Angular CLI supports Service Worker generation by simply adding PWA support: ng add @angular/pwa One-size-fits-all Service Worker Pre-defined functionality, limited customizability PWA Produktivitäts-PWAs auf Desktopniveau (Hands-on) Angular meets Project Fugu
38. Workbox Toolchain by Google Includes a CLI Generates a service worker implementation from directory contents (e.g., build output, or our development directory) Allows you to modify the service worker behavior (maximum flexibility) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
39. Service Worker 1. In your console, run: npm run pwa 2. Test in DevTools: F12 > Application > Service Worker 3. Install the app: Address Bar > Install Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA LAB #9
40. Push Notifications Just as native apps, PWAs can receive push notifications Combination of two technologies: Web Notifications and Push API Supported by Chrome, Edge, Firefox, Safari (on macOS) Support coming to iOS and iPadOS in version 16.4 (currently a RC) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
41. Service Worker Debugging More information on installed service workers can be found on • about://serviceworker- internals (Chromium-based browsers) • about:serviceworkers (Mozilla Firefox) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
42. Service Worker Debugging Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA
43. Lighthouse Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA Auditing tool by Google, integrated in Chrome DevTools Automatically checks performance metrics, PWA support, accessibility, SEO and other best practices and gives tips on how to improve Can simulate mobile devices
44. Lighthouse 1. Make sure only one tab/window of your PWA is open 2. Open DevTools: F12 > Lighthouse 3. Make sure to select at least the “Progressive Web App” category 4. Click “Analyze page load” Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) PWA LAB #10
45. Paint PWA Capabilities Progressive Enhancement Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Agenda
46. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on)
47. Project Fugu Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities »Let’s bring the web back – API by API« Thomas Steiner, Google
48. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities Contacts Picker Screen Wake Lock API File System Access API Shape Detection API
49. Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities https://goo.gle/fugu-api-tracker
50. Browser Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities navigator.share({ url: 'http://example.com' }); ShareIntent DataTransferManager … NSSharingServicePicker
51. File System Access API Some applications heavily rely on working with files (e.g. Visual Studio Code, Adobe Photoshop, …) File System Access API allows you to open, save and override files and directories Supported by Chrome, Edge Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities
52. File System Access API 1. Add the following buttons to the <nav> bar in app.component.html (before the color input): <button (click)="open()">Open</button> <button (click)="save()">Save</button> <button (click)="copy()">Copy</button> <button (click)="paste()">Paste</button> <button (click)="share()">Share</button> Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #11
53. File System Access API 2. Add the following lines at the top of app.component.ts: readonly fileOptions = { types: [{ description: 'PNG files', accept: {'image/png': ['.png']} }] }; Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #11
54. File System Access API 3. Add the following lines to the save() function: const blob = await this.paintService.toBlob(this.canvas!.nativeElement); const handle = await window.showSaveFilePicker(this.fileOptions); const writable = await handle.createWritable(); await writable.write(blob); await writable.close(); Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #11
55. File System Access API Add the following code to the open() function: const [handle] = await window.showOpenFilePicker(this.fileOptions); const file = await handle.getFile(); const image = await this.paintService.getImage(file); this.context!.drawImage(image, 0, 0); Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #12
56. Async Clipboard API Allows reading from/writing to the clipboard in an asynchronous manner (UI won’t freeze during long-running operations) Reading from the clipboard requires user consent first (privacy!) Supported by Chrome, Edge and Safari and Firefox (plain- text only) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities
57. Async Clipboard API Add the following code to the copy() function: await navigator.clipboard.write([ new ClipboardItem({ "image/png": this.paintService.toBlob(this.canvas!.nativeElement) }), ]); Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #13
58. Async Clipboard API const clipboardItems = await navigator.clipboard.read(); for (const clipboardItem of clipboardItems) { for (const type of clipboardItem.types) { if (type === 'image/png') { const blob = await clipboardItem.getType(type); const image = await this.paintService.getImage(blob); this.context!.drawImage(image, 0, 0); } } } Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #14
59. Web Share API Allows sharing a title, URL, text, or files API can only be invoked as a result of a user action (i.e. a click or keypress) Supported by Chrome, Edge, Safari and Firefox (Android only) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities
60. Web Share API const blob = await this.paintService.toBlob(this.canvas!.nativeElement); const file = new File([blob], 'untitled.png', {type: 'image/png'}); const item = { files: [file], text: 'Awesome drawing' }; if (navigator.canShare(item)) { await navigator.share(item); } Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #15
61. File Handling API Register your PWA as a handler for file extensions Requires installing the application first Declare supported extensions in Web App Manifest and add imperative code to your application logic Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities
62. File Handling API 1. Add the following property to your manifest (manifest.webmanifest): "file_handlers": [{ "action": "/index.html", "accept": { "image/png": [".png"] } }] Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #16
63. File Handling API 2. Add the following code to ngAfterViewInit() in app.component.ts: if ('launchQueue' in window) { window.launchQueue.setConsumer(async params => { const [handle] = params.files; if (handle) { const file = await handle.getFile(); const image = await this.paintService.getImage(file); ctx.drawImage(image, 0, 0); } }); } Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #16
64. File Handling API 3. Rebuild PWA: npm run pwa Note: Wait for a few seconds and reload the application after opening, as the PWA needs to fetch the new files first. about://apps Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities LAB #16
65. Summary - Project Fugu helps the web to become more and more capable - Project Fugu APIs could bring many more app experiences to the web (IDEs, productivity apps, etc.) - But: Web is threatened by alternative approaches and platforms, support for modern Web API varies from platform to platform - You can make a difference! - File bugs in browser engine bugtrackers - File Fugu requests: https://goo.gle/new-fugu-request Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Capabilities
66. Paint PWA Capabilities Progressive Enhancement Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Agenda
67. Overview Use available interfaces and functions of a system (opposite of Graceful Degradation) Users with modern, feature-rich browsers get a better experience Apps are available on older browsers, but with limited functionality Concept: Browser feature support should grow over time—thereby more users can enjoy an increasing number of features Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Progressive Enhancement
68. Overview if ('serviceWorker' in navigator) { navigator.serviceWorker.register(…) .then(() => /* … */); } In JavaScript: check whether an API/feature is available. If yes—use it! Otherwise: 1. Disable the functionality 2. Fall back to an alternative API (if available) Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Progressive Enhancement
69. New powerful APIs regularly ship with new releases of Chromium-based browsers Some only add minor finishing touches, others enable whole application categories as productivity apps to finally make the shift to the web Some APIs already made their way into other browsers (e.g., Web Share) Fugu process makes sure that capabilities are implemented in a secure, privacy-preserving manner Let’s make the web a more capable platform! Angular meets Project Fugu Produktivitäts-PWAs auf Desktopniveau (Hands-on) Summary
70. Thank you for your kind attention! Christian Liebel @christianliebel christian.liebel@thinktecture.com