WWDC 2020 Session Notes

Thank You 🎉

Last years WWDC Session Notes was so successful that I decided to continue this form of WWDC session summary. I would like to take the moment to thank all of you for contribution, feedback, support and reading my session notes 🙏

Intro

Usually it is much faster to read through some bullet points instead of watching a 50 min session video. Then if you find something interesting you can still watch it.

Sessions that are exceptionally mentionable are highlighted using a ★.

This is work in progress since it is a lot of effort to watch all the videos by myself. So either please be patient or just open up an issue to make a suggestion which session notes you like to see next :)

Contribution

Feel free to submit a PR if I got something wrong or you have a suggestion for improvement. Please also have a look in CONTRIBUTING.md if you want to contribute.

Thanks so much to EVERYBODY who contributed and improved the overall quality of the notes and those who added complete notes to the list.

Mentions

This repo has already been mentioned many times on Twitter and apart from this also in the following places:

Interesting WWDC-Related Links

Keynote ★
Platform State of the Union ★
(TO-DO) Adopt the new look of macOS
(TO-DO) Advances in UICollectionView
(TO-DO) Advances in diffable data sources
(TO-DO) Build Metal-based Core Image kernels with Xcode
(TO-DO) Build SwiftUI apps for tvOS
(TO-DO) Build an Action Classifier with Create ML
(TO-DO) Build complications in SwiftUI
(TO-DO) Build trust through better privacy
Configure and link your app clips
(TO-DO) Create great enterprise apps: A chat with Box's Aaron Levie
(TO-DO) Design for iPad
(TO-DO) Detect Body and Hand Pose with Vision
(TO-DO) Distribute binary frameworks as Swift packages
Explore ARKit 4
Streamline your app clip
Explore app clips
(TO-DO) Inspect, modify, and construct PencilKit drawings
(TO-DO) Introducing StoreKit Testing in Xcode
(TO-DO) Introduction to SwiftUI
(TO-DO) Lists in UICollectionView
(TO-DO) Make your app visually accessible
(TO-DO) Meet Nearby Interaction
(TO-DO) Meet Safari Web Extensions
(TO-DO) Meet Scribble for iPad
(TO-DO) Meet WidgetKit
(TO-DO) Modern cell configuration
(TO-DO) One-tap account security upgrades
(TO-DO) Optimize the Core Image pipeline for your video app
(TO-DO) Port your Mac app to Apple Silicon
(TO-DO) Record stereo audio with AVAudioSession
(TO-DO) Support multiple users in your tvOS app
(TO-DO) Swan's Quest, Chapter 1: Voices in the dark
(TO-DO) Swift packages: Resources and localization
(TO-DO) Use model deployment and security with Core ML
What's new in App Store Connect
(TO-DO) What's new in HealthKit
(TO-DO) What's new in Low-Latency HLS
(TO-DO) What's new in Mac Catalyst
(TO-DO) What's new in PencilKit
(TO-DO) What's new in RealityKit
(TO-DO) What's new in SiriKit and Shortcuts
What's new in Swift
What's new in SwiftUI
(TO-DO) What's new in education
(TO-DO) What's new in location
(TO-DO) What's new in managing Apple devices
(TO-DO) iPad and iPhone apps on Apple Silicon Macs
Accelerate your app with CarPlay
(TO-DO) Add custom views and modifiers to the Xcode Library
(TO-DO) Advancements in Game Controllers
(TO-DO) App essentials in SwiftUI
(TO-DO) Bring your Metal app to Apple Silicon Macs
(TO-DO) Broaden your reach with Siri Event Suggestions
(TO-DO) Build GPU binaries with Metal
(TO-DO) Build an Endpoint Security app
(TO-DO) Build for iPad
(TO-DO) Build for the iPadOS pointer
(TO-DO) Build with iOS pickers, menus and actions
(TO-DO) Create a seamless speech experience in your apps
(TO-DO) Create app clips for other businesses
(TO-DO) Create complications for Apple Watch
(TO-DO) Custom app distribution with Apple Business Manager
(TO-DO) Design for Game Center
(TO-DO) Design for intelligence: Apps, evolved
(TO-DO) Design for intelligence: Discover new opportunities
(TO-DO) Design for intelligence: Make friends with "The System"
(TO-DO) Design for intelligence: Meet people where they are
(TO-DO) Design great app clips
(TO-DO) Design with iOS pickers, menus and actions
(TO-DO) Discover Core Image debugging techniques
(TO-DO) Discover HLS Blocking Preload Hints
(TO-DO) Edit and play back HDR video with AVFoundation
(TO-DO) Enable encrypted DNS
(TO-DO) Evaluate and optimize voice interaction for your app
(TO-DO) Explore Computer Vision APIs
(TO-DO) Explore Packages and Projects with Xcode Playgrounds
(TO-DO) Explore logging in Swift
(TO-DO) Explore the new system architecture of Apple Silicon Macs
(TO-DO) Export HDR media in your app with AVFoundation
(TO-DO) Get your test results faster
(TO-DO) Handle interruptions and alerts in UI tests
(TO-DO) Handle the Limited Photos Library in your app
(TO-DO) Handle trackpad and mouse input
(TO-DO) Harness Apple GPUs with Metal
(TO-DO) Introducing Car Keys
(TO-DO) Leverage enterprise identity and authentication
(TO-DO) Master Picture in Picture on tvOS
(TO-DO) Meet Face ID and Touch ID for the web
Meet the new Photos picker
(TO-DO) Modernize PCI and SCSI drivers with DriverKit
(TO-DO) Optimize Metal Performance for Apple Silicon Macs
(TO-DO) Optimize live streams with HLS Playlist Delta Updates
(TO-DO) Secure your app: threat modeling and anti-patterns
(TO-DO) Streamline your app clip
(TO-DO) Support hardware keyboards in your app
(TO-DO) Support local network privacy in your app
(TO-DO) Swan's Quest, Chapter 2: A time for tones
(TO-DO) Tap into Game Center: Dashboard, Access Point, and Profile
(TO-DO) Tap into Game Center: Leaderboards, Achievements, and Multiplayer
(TO-DO) Visually edit SwiftUI views
(TO-DO) What's new for web developers
(TO-DO) What's new in CareKit
What's new in Wallet and Apple Pay
(TO-DO) What's new in assessment
(TO-DO) What's new in watchOS design
(TO-DO) What’s new with in-app purchase
(TO-DO) Widgets Code-along, part 1: The adventure begins
(TO-DO) Widgets Code-along, part 2: Alternate timelines
(TO-DO) Widgets Code-along, part 3: Advancing timelines
(TO-DO) Adapt ad insertion to Low-Latency HLS
(TO-DO) App accessibility for Switch Control
(TO-DO) Architecting for subscriptions
(TO-DO) Author fragmented MPEG-4 content with AVAssetWriter
(TO-DO) Bring keyboard and mouse gaming to iPad
(TO-DO) Build Image and Video Style Transfer models in Create ML
(TO-DO) Build a SwiftUI view in Swift Playgrounds
(TO-DO) Build document-based apps in SwiftUI
(TO-DO) Build local push connectivity for restricted networks
(TO-DO) Build location-aware enterprise apps
(TO-DO) Create Swift Playgrounds content for iPad and Mac
(TO-DO) Debug GPU-side errors in Metal
(TO-DO) Decode ProRes with AVFoundation and VideoToolbox
(TO-DO) Deploy Apple devices using zero-touch
(TO-DO) Design for the iPadOS pointer
(TO-DO) Design high quality Siri media interactions
(TO-DO) Discover AppleSeed for IT and Managed Software Updates
(TO-DO) Discover WKWebView enhancements
Embrace Swift type inference
(TO-DO) Expand your SiriKit Media Intents to more platforms
(TO-DO) Expanding automation with the App Store Connect API
(TO-DO) Explore numerical computing in Swift
(TO-DO) Explore the Action & Vision app
(TO-DO) Gain insights into your Metal app with Xcode 12
(TO-DO) Get the most out of Sign in with Apple
(TO-DO) Getting started with HealthKit
(TO-DO) Improve stream authoring with HLS Tools
(TO-DO) Keep your complications up to date
(TO-DO) Make apps smarter with Natural Language
(TO-DO) Meet Audio Workgroups
(TO-DO) Optimize Metal apps and games with GPU counters
(TO-DO) Optimize the interface of your Mac Catalyst app
(TO-DO) Reduce Latency with HLS Blocking Playlist Reload
(TO-DO) Stacks, Grids, and Outlines in SwiftUI
(TO-DO) Support performance-intensive apps and games
(TO-DO) Swan's Quest, Chapter 3: The notable scroll
(TO-DO) Sync a Core Data store with the CloudKit public database
(TO-DO) The Push Notifications primer
(TO-DO) The artist’s AR toolkit
(TO-DO) Triage test failures with XCTIssue
(TO-DO) Unsafe Swift
(TO-DO) What's new in ClassKit
(TO-DO) What's new in Core NFC
(TO-DO) What's new in ResearchKit
(TO-DO) What's new in USD
(TO-DO) What's new in streaming audio for Apple Watch
(TO-DO) Write tests to fail
(TO-DO) XCTSkip your tests
(TO-DO) Accessibility design for Mac Catalyst
(TO-DO) Add configuration and intelligence to your widgets
(TO-DO) Advancements in the Objective-C runtime
(TO-DO) AutoFill everywhere
(TO-DO) Background execution demystified
(TO-DO) Become a Simulator expert
(TO-DO) Beyond counting steps
(TO-DO) Boost performance and security with modern networking
(TO-DO) Build SwiftUI views for widgets
(TO-DO) Build customized ML models with the Metal Performance Shaders Graph
(TO-DO) Build localization-friendly layouts using Xcode
(TO-DO) Build scalable enterprise app suites
(TO-DO) Capture and stream apps on the Mac with ReplayKit
(TO-DO) Control training in Create ML with Swift
(TO-DO) Core Data: Sundries and maxims
(TO-DO) Create custom apps for employees
(TO-DO) Create quick interactions with Shortcuts on watchOS
Data Essentials in SwiftUI
(TO-DO) Decipher and deal with common Siri errors
(TO-DO) Deliver a better HLS audio experience
(TO-DO) Design for location privacy
(TO-DO) Design great widgets
(TO-DO) Diagnose performance issues with the Xcode Organizer
(TO-DO) Discover how to download and play HLS offline
(TO-DO) Discover ray tracing with Metal
(TO-DO) Discover search suggestions for Apple TV
(TO-DO) Eliminate animation hitches with XCTest
(TO-DO) Empower your intents
(TO-DO) Feature your actions in the Shortcuts app
(TO-DO) Formatters: Make data human-friendly
(TO-DO) Get models on device using Core ML Converters
(TO-DO) Get to Know Metal Function Pointers
(TO-DO) Handling FHIR without getting burned
(TO-DO) Identify trends with the Power and Performance API
(TO-DO) Integrate your app with Wind Down
(TO-DO) Meet Watch Face Sharing
(TO-DO) Refine Objective-C frameworks for Swift
(TO-DO) SF Symbols 2
(TO-DO) Safely manage pointers in Swift

Keynote ★

https://developer.apple.com/wwdc20/101/

App Library
- Automatically created at the end of your app pages on the Home Screen
- Makes it easier than ever to get to your apps
Widgets on Home Screen
- Richer UI - more possibilities
- Different sizes to choose one that best fits your needs
- Droppable on the home screen
- Widget gallery to explore all widgets
- SmartStack as intelligent assistant which enables you to scroll through your widgets
Picture in Picture on iPhone
- Swipe to the side, out of the screen, and audio keeps playing
- Video keeps playing when switching apps
Siri
- Got smarter and has a new interface which doesn't block your UI anymore
- Can now send audio messages using the messages app - completely hands free
Translate as new app of offline conversation translate
- Conversation mode when switching to landscape mode in the app
Messages
- Pinning messages to the top of the screen
- Memoji gets hundreds of new options to customize your avatar, including masts, fist-pumps and more
- Group conversations got some ❤️ by adding inline replies and most-active member widget
Maps
- More countries like UK, Ireland and Canada
- It gets easier to find places you love and how you get there in an ecological way
- Maps offers Guides that help you discover great new places
- Brand new cycling option to reduce your carbon footprint
- EV-Routing option to optimize your route for electric cars - e.g. by selecting routes with charging station on your way
CarPlay
- New wallpaper option
- New categories for CarPlay apps: Parking, EV-Charging, and Quick-Food ordering
- Car Key API - first supported by BMW - enable open/close/start your car
App Clips as small, fast parts of an app, designed for speed
- A way to discover what the App Store has to offer
- Launchable from the web, by NFC tags, QR codes or the brand new Apple designed tags
- Needs to be smaller than 10 MB
- Use Sign in With Apple to provide the most seamless app experience
- Use Apply Pay to allow quick payments
- Option to download the full app
iPadOS
- Photos app gets an all new side bar - new way to navigate and organize your photos
- Incoming calls become unobtrusive using notification style UI (available for all apps: WhatsApp, Skype, ...) • available for iOS too
- New searching experience
Apple Pencil
- Scribble lets you hand-write in any text field. iOS converts your writing then to text
- Smart Selection lets you select single words / characters you've written using your pencil using iOS text recognition features
- DataDetectors are used to automatically detect e.g. phone numbers, email addresses
AirPods
- are now able to automatically switch to new incoming audio sources
- Spacial Audio for AirPods Pro (AirPods Motion API) to emulate movie theatre experience • use AirPods gyroscope to sync the sound to your head position/orientation
watchOS 7
- Configure your own watch faces styled by your current living style
- Watch faces can now be shared on Websites or via the usual sharing features of watchOS
- Workout app adds dance, cooldown, functional training and more workouts plus it is renamed to Fitness
- Sleep Tracking is a new app that helps you to get to bed at time using Wind Down which dims all distractions (also available in iPhone)
- Handwashing detection to make sure you wash as long as you're supposed to (20 seconds shown in demo)
Privacy Improvements
- Location only share rough location
- Camera ...
- Tracking Control require apps to ask before tracking
- App Privacy makes data tracked by developers visible to the users before they download the app
Home
- Alliance among different manufacturers to make smart home devices even better
- Adaptive lighting to auto-adjust color temperature throughout the day
- Cameras get activity zones, richer notifications
- Face recognition extends to Home Pod
- Camera content can be displayed on TV via your Apple TV
- Apple TV
  - Picture in Picture
  - Better Airplay in full 4K
  - Apple TV+ already on over 1 billion devices
  - Foundation as newest production only available on Apple TV+
macOS Big Sur
- use of a lot of translucency
- Design refresh for all system apps
- New side and compact, space efficient toolbars
- Control center now on the mac
- Notification Center
  - Notification grouping
  - iOS widgets also available on the mac
- Messages with new search, photo picker, messages effects, pin conversations, inline replies and more
- Maps with indoor-maps, favorites, ETA from friends and all of it implemented using Catalyst
- Safari with 50% faster page loading, Privacy Report via toolbar button, Web Extensions API, built-in translation
Mac
- Processor-transition to Apple Silicon - Apple's own processor line - bye bye Intel 👋
- Universal 2 is the new universal binary type that contains binaries compiled for both architectures
- Rosetta 2 lets existing app run on new architectures from day one by making them compatible at installation time
  - Supports iPhone and iPad apps directly

Platform State of the Union ★

https://developer.apple.com/wwdc20/102/

Some new features: AirPods Motion API, SwiftPM resources, New Catalyst Controls, ARKit 4, Widgets in SwiftUI, Depth API, TestFlight 100 Testers, SwiftUI Lifecycle, Catalyst Native Screen Resolution, Complications in SwiftUI, Xcode StoreKit Testing, HomePod Music Services, App Clips, New SwiftUI Controls, Xcode Tabs, ...
Users can make your app the default app used for email and set a default web browser
Developers can bring existing web-browser extensions to Safari using a new command line tool
FindMy can now leverage all iPhones out there to locate your devices, even if they are not connected to the internet (applicable to all kinds of objects)
Mac transition to Apple Silicon - Apple's own processor line - brings more security, better performance, longer battery life and amazing graphics
- Advantages
  - Cached cloud content can be kept up to date for days, even if your mac goes to sleep
  - Higher quality, hardware-supported 4:4:4 encoder for e.g. better image quality when connecting your Mac via SideCar
  - Best-In-Class platform security
- Apple provides a Developer Transition Kit
  - Mac mini enclosure + A12Z SoC
  - 16GB memory, 512GB SSD
  - macOS Big Sur Developer Beta + Xcode
- First Macs will appear by end of the year
Universal 2 create universal apps that run on both Apple Silicon and older architectures
Porting to Apple Silicon takes only a few days, even for grown projects. As a result, all Apple system apps are already converted in macOS Big Sur
Rosetta 2 lets existing app run on new architectures from day one by making them compatible at installation time
- Supports iPhone and iPad apps directly
iOS/iPad Apps natively on Mac
- Apps will run natively on the Mac
- Apps will automatically support features like resizing, Dark Mode, scrolling, multi-window, native share sheets, ...
- Apple plans to make iOS/iPadOS apps available on the App Store for macs running with Apple Silicon
macOS Big Sur - macOS 11
- Rounded dock 🎉
- Control Center for mac
- New translucent look for notification center
- Refined layout for menus of the menu bar
- New sheet presentation - parent window is dimmed
- Completely re-designed toolbars with extending search fields and images provided by SF-Symbols
- App-specific accent color
- macOS Catalyst
  - macOS-specific implementation of iOS API's
  - Native resolution support
  - Messages re-written in Catalyst
  - SwiftPlaygrounds will support multiple windows
iPadOS
- New sidebars can now expand from two-column layout to three-column layout - even available in portrait mode
- Recommended to use side bars instead of tab bars
- New inline emoji picker - also for custom apps
- New color picker UI - easy to adopt
- New Depth APIs give you access to precise distance info captured by the LiDAR scanner on iPad
- Dramatic improvement of people inclusion and motion detection - objects can be placed in front or behind real objects in the world
- Apple Pencil
  - New handwriting improvements will work in your apps without any additional work
  - Hand-writing for any UITextField
  - Automatic support for Scribble which converts any hand-written text to typed text
  - Stroke API gives access to the strokes as the user draws
  - Smart Selection lets you select single words / characters you've written using your pencil and iOS text recognition features
- iOS 14
  - Widgets
    - New widgets take UX to a whole new level
    - Users can move them to the home screen
    - Widgets are packed as SwiftUI archives which are optimized for performance
    - Are rendered by the system at the right time, when the user needs them
    - Can be smartly stacked to consume less space and let the user flip through them
    - Stack automatically moves the right widget to the top at just the right time
    - Configurable in the Widget Gallery
  - App Clips
    - Small part of the app which is light/fast and easy to discover
    - Can use Apple Pay and Sign in With Apple to provide a seamless UX
    - Easily discoverable in a variety of ways, like other apps or places in the real world via new Apple-designed (QR-like) codes which are basically NFC tags
    - Introduce users to what your app offers
  - Misc. New Features
    - Cycling directions, Guides and EV routing in Maps
    - Translate app
    - Messages inline replies
    - Car keys
    - App Library
    - On device dictation
- watchOS 7
  - Xcode is now able to preview watchOS complications
  - SwiftUI complications
  - Watch-face sharing via any sharing capabilities, e.g Messages, social media, etc
- Xcode 12
  - Cleaner, more expressive UI
  - Navigators realized using the new Side Bar
  - Any kind of content is now openable in document tab
  - Navigate through nested calls in compiler failure messages
  - StoreKit test environment lets you unit test In-App Purchase and Subscriptions
  - New StoreKit transaction manager shows details during debugging
  - Faster code completion with simplified presentation
- SwiftUI
  - All SwiftUI apps will continue to compile without additional changes (Apple added no breaking changes - just extensions)
  - Lazy statement makes large collections of views way less memory hungry and makes scrolling snappy again
  - Now contains app-structure APIs for all Apple platforms, e.g. @main, @SceneBuilder, Settings, ...

Adopt the new look of macOS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Advances in UICollectionView

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Advances in diffable data sources

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build Metal-based Core Image kernels with Xcode

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build SwiftUI apps for tvOS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build an Action Classifier with Create ML

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build complications in SwiftUI

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build trust through better privacy

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Configure and link your app clips

https://developer.apple.com/wwdc20/10146/

Presenters: Ada Chan, Luming Yin

Intro
- App Clips provide entry points to your users to experience your app with minimal friction.
- Use deep-linked navigation to present the App Clip
User Quest
- User is in a smoothie shop. They see an NFC tag and tap it using the phone.
- An app clip shows up on the phone's lockscreen with summarized detail about that smoothie.
- User taps "open" and a single screen of your app shows up.
- User can then proceed to the payment via Apple Pay.
Activation
- Tapping NFC tags or scanning QR codes - they're just deep links after all (a URL)
- Maps and Siri Nearby Suggestions (for registered businesses)
- Smart app banner in your website (shown in Safari and Messages)
- Apple App Clip codes will be introduced later this year (it's a prettified QR code)
- If the user already has the your app installed, following an App Clip link will open the full app instead.
Setup
- Configure web server and App Clip for link handling
  - Web Server: Update the apple-app-site-association file
  - App Clip: Add associated domains entitlement and handle NSUserActivity
- Configure App Clip default and advanced experiences on App Store Connect
  - Layout requirements:
    - Title: 18 chars limit
    - Subtitle: 43 chars limit
    - Image:
      - Size: 3000 x 2000px
      - Aspect Ratio: 3:2
      - Format: png/jpg
      - Transparency: No
  - Best Practices
    - URL mapping is based on most specific prefix match against registered App Clip experience URLs
    - Your App Clip must be able to launch using an exact registered URL. For example:
      - App registers https://bikesrental.com/rent instead of https://website.com/rent?bikeID=2
      - When receiving https://website.com/rent?bikeID=2, it should be able to deliver the https://website.com/rent App Clip
      - App is responsible for parsing the remaining arguments and presenting the specific bike with ID 2
      - You can also register a more specific URL if you want to provide a different and more specific App Clip experience for it
- Configure the Smart App Banner to open App Clip (add this if the content of your web page can be delivered as a better and more streamlined app experience)
  - Add/update your website's HTML to add the Smart App Banner meta tag
Test
- Specify an App Clip URL under the _XCAppClipURL environment variable to launch App Clip from Xcode
- TestFlight - new App Clips section in App Store Connect

Create great enterprise apps: A chat with Box's Aaron Levie

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for iPad

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Detect Body and Hand Pose with Vision

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Distribute binary frameworks as Swift packages

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore ARKit 4

https://developer.apple.com/wwdc20/10611

Presenters: Quinton Petty, Praveen Gowda

Location Anchors
- Geo-referenced AR Content
- Uses "visual localisation" from Maps
  - No processing in the cloud
  - No images sent back to Apple
- Pinned to a geo-location
- 3 main parts
- Device support A12 Bionic or later + GPS support
- Requires availability checks for both device and location
- ARGeotrackingStatus
  - State
  - StateReason
  - accuracy: low, medium, high
- Methods for converting between local and latitude / longitude positions via getGeoLocation(forPoint:)
- Recommended to point towards buildings / static objects
- May struggle in wide open spaces (e.g a field)
- Locations currently available: San Francisco Bay Area, Los Angeles, New York, Chicago and Miami
- Sample: Tracking Geographic Locations in AR
Scene Geometry
- Topological map of environment
- Semantic classification
- Allowing for:
  - Occlusion
  - Physics
  - Virtual lighting
- Based upon the Depth API
Depth API
- Provides a dense depth image
- Use sceneDepth under frame semantics
- Provides dense depth image
- Runs at 60Hz, on every ARFrame
- depthMap and confidenceMap provided
- Depth map provided as CVPixelBuffer
- ARConfidenceLevel: high, medium or low
- Available on LiDAR devices
Object Placement
- Improvements in Raycasting
- Quicker placement with LiDAR sensor
- Allows for placing on a white wall
- Raycasting is recommend over hit-testing
- 2 types of query:
  - Raycast
  - Tracked Raycasts
Face Tracking
- Support added for non-TrueDepth iPhones
- Requires A12 processor or later
- iPhone SE (2020)

Streamline your app clip

https://developer.apple.com/wwdc20/10120/

Presenters: Yongjun Zhang, Luming Yin

Best practices
- Focus on essential tasks
- Limit the features. Reserve complex features for your app
- Require all assets for initial experience
- Do not include splash screens
- Avoid requiring people to sign up before finishing their task
- Only ask for location and notification permissions if needed (more on this below)
- Make sure your App Clip has the same name and icon as your app
- Put shared assets in a shared asset catalog
- Authentication
  - Support Sign in with Apple
  - Use ASWebAuthenticationSession for other federated login
  - Offer username and password login for existing users
  - Offer "Sign In With Apple" upgrade in the app
- For privacy reasons, and because App Clips are ephemeral, some contents are not available to App Clips, such as HealthKit info
- App Clips can request permission to use Bluetooth, the camera, and microphone
Streamlining Transactions
- 2 new types of ephemeral permissions: Location and Notification
  - Allows App Clips to check if the user is within a region, without prompting for location permission
    - Add NSAppClipRequestLocationConfirmation with value true in your Info.plist to enable this
    - Supports checking a region with a radius of up to 500 meters
  - Allows App Clips to send notifications for up to 8 hours after each launch, without prompting for notification permission.
    - Add NSAppClipRequestEphemeralUserNotification with value true in your Info.plist to enable this
    - Check the authorization status in the NotificationSettings, under the new .ephemeral status
  - Users can explicitly disable these permissions via App Clip settings panel
  - App Clips can prompt the user for full Location and Notifications access, although discouraged
- Strongly suggest using ApplePay
- Strongly suggest using "Sign In With Apple"
- Use AuthenticationServices API to sign your users in without showing a login screen (assuming they have already previously signed up in your website for instance)
Transition users to your app
- iOS suggests downloading your app from App Clip experiences, banners and App Clip settings
- You can embed StoreKit SKOverlay in a view
  - Suggestion: display this overlay only after the user finishes their task, e.g. after payment
- Transfer data on device with a secure App Group
  - Only accessible between your App Clip and your app
  - Once user downloads the app, the App Group will be transferred to the app after the App Clip is deleted
  - Migrate your "Sign In With Apple" session from your App Clip by persisting the user ID in the secure App Group. Use ASAuthorizationAppleIDProvider to verify the user's session without prompting UI

Explore app clips

https://developer.apple.com/wwdc20/10174

Presenters: James Savage, Luming Yin

What is an App Clip?
- App Clip Experience URL is required to run App Clips which are parts of your app
- On-demand app experiences
App Clip Experiences
- App Clip URLs are similar to Universal Links
- Registered using App Store Connect
- Surfaced through user actions via NFC / QR codes / links in Safari or other apps / Apple App Clip codes combine the ease of NFC and visual codes so they can be tapped or scanned
New App Clip Target in Xcode
- Contains all assets
- Needs to be submitted along with the app for review
- It gets downloaded separately if the app is not installed on user’s device
- Should be as small as possible for quick downloads (less than 10MB but with enough assets to load UI quickly)
- Focused user flows - one at a time
Demo
- Ordering smoothies
- New App Clip target embedded in the application
  - Name and bundle ID for App Clip added
  - It can build and run with boilerplate code right away
- Add code and resources
  - NutritionFacts dependency added
  - Create new Assets Catalog as shared assets
    - Drag App Icon, Colors and other image assets required for app clip into the shared assets catalog
  - Add the required model and view files to App Clip target
    - Let go of unwanted Swift files like navigation
  - Conditionally compile out the references to files not added to App Clip
    - Build Settings > Swift Compiler custom flags > Active Compilation Conditions > Add APPCLIP condition for required schemes.
    - Use #if !APPCLIP to compile out unwanted references in Swift code
- Write code for App Clip
  - Add required models and views to the new AppClip
  - Include existing views in the App Clip’s content view
Technology Overview
- App Clips are built using same UI components as an app
- When launched, it receives NSUserActivity
  - Use the URL to identify the type of experience to be handled
- Unlike extensions, App Clip can make use of all iOS SDK APIs
  - Note: Access to sensitive data is limited
  - Always check if data is available
- New location confirmation API helps get the location quickly without requesting full access
- New API for migrating data from App Clip to main app using shared data container once installed
- App Clip and its local storage will be deleted after period of inactivity
  - Not included in backups
- Can not be launched via Universal Links or custom URL schemes
- Can not include bundle extensions like content blockers
Device states and transitions
- User scans QR code
- iOS locates, downloads and runs the App Clip
- If the App Clip is not revisited for a while, the App Clip and its data gets deleted
  - Treat App Clip data as cache; which can be deleted
- If the App Clip is visited frequently, its lifespan will be extended and data may never be cleared
  - When user downloads your app, iOS will automatically migrate the data container and the permissions that were already granted by the user
  - iOS still deletes the App Clip and its container after copying the data container to the app
Other technologies
- Apple Pay
- Notifications
- SwiftUI
- SKOverlay / AppStoreOverlayModifier (refer to What’s new with in-app purchase session)
- ASAuthorizationController for sign in or sign up

Inspect, modify, and construct PencilKit drawings

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Introducing StoreKit Testing in Xcode

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Introduction to SwiftUI

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Lists in UICollectionView

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Make your app visually accessible

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet Nearby Interaction

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet Safari Web Extensions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet Scribble for iPad

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet WidgetKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Modern cell configuration

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

One-tap account security upgrades

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Optimize the Core Image pipeline for your video app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Port your Mac app to Apple Silicon

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Record stereo audio with AVAudioSession

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Support multiple users in your tvOS app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Swan's Quest, Chapter 1: Voices in the dark

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Swift packages: Resources and localization

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Use model deployment and security with Core ML

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in App Store Connect

https://developer.apple.com/wwdc20/10651

Presenter: Daniel Miao

App Clips
- Beta Testing
  - Safari App Clip banner appears when a website is associated with an App Clip. Tapping brings up the App Clip Card. Tapping the card opens the app itself.
  - App Clips can be invoked from Safari, Messages, Maps, NFC Tags, QR Code or Location
  - Invocation URL from the website is used what to show on the App Clip Card and is passed to it upon tap of the banner
  - App Clip is packaged with the app and delivered to ASC
  - In the new App Clip Invocation Section on ASC you can provide titles and along with invocation URLs used in the App Clip
  - Title-URL combinations are selectable in TestFlight and take you directly to the App Clip by passing the invocation URL (without showing the App Clip Card)
- App Clip Card Meta Data
  - Header image, App Clip title, App Clip subtitle, call to action button
  - Enter the default meta data on the apps version page on ASC
  - Associate your website with the App Clip by including the meta-data tag <meta name="apple-itunes-app", content:"app-id=123456", app-clip-bundle-id:=org.appname.clip>
  - Use Advanced App Clip Experiences to get customized meta data and association with e.g. location in Maps
    - Advanced assistant on your app's version page on ASC to setup advanced experience
    - You can select to promote Your own business or Other Businesses (e.g. Yelp)
  - You have to specify an Apple App Site Association file (like with universal links) that has to match the Associated Domains Entitlement in your app
  - Manage / Debug your website association on ASC
Game Center
- Challenges other players to get achievement
- Recurring Leaderboards to collect scores for a certain period of time
  - Reset after that time
  - Configurable on ASC
Family Sharing for Subscriptions
- Subscriptions can be shared among the family form fall 2020
- Auto-renewable subscriptions
- Non-consumables
- Automatic sharing for new customers
- Existing subscribers can opt-in
- Family-shared in-app purchase can be enabled on the ASC-In-App-Purchase section of your app
- Once turned on it cannot be tuned off again
App Store Connect API
- Over 200 new endpoints will be added
- Add App Meta Data API
  - Create new version
  - Set app pricing
  - Edit app and version metadata
  - Associate build with version
  - Submit app for review
- Add Power and Performance Metrics and Diagnostics API

What's new in HealthKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in Low-Latency HLS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in Mac Catalyst

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in PencilKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in RealityKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in SiriKit and Shortcuts

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in Swift

https://developer.apple.com/wwdc20/10170

Presenters: Ted Kremenek, Kyle Macomber

Swift Releases
- Xcode 11.4 - Swift 5.2
- Xcode 12 (beta) - Swift 5.3
Runtime Performance
- Code Size
  - Code size is the part of the app that represents the machine code representation of the app's logic
  - Swift 5.3 is below 1.5 times the code size of Objective-C version (based on app that ships with iOS)
  - Size difference is inevitable because of Swift safety features
  - SwiftUI app binary code size can be reduced by 40% (based on MoviesSwiftUI app)
- Memory Layout
  - Comparing models with three properties in Obj-C (NSUUID, NSString and float) and Swift (UUID, String, Float)
  - In Obj-C, object variables are just pointers which then hold a pointer to their properties
  - Swift's use of value types avoid the need to access values via pointers (UUID and Strings)
  - Significant memory benefit because it is allocated directly within array storage (contiguous block of memory)
  - Heap memory use comparison: 20kB in Swift 5.1 vs 35kB in Obj-C (400 models in array)
  - Swift's Standard Library now is below Foundation in the stack which means it can be used to develop low-level frameworks for Objective-C frameworks where previously C has to be used!
Diagnostics
- New diagnostics in the Swift compiler result in more precise and actionable errors
- Additional notes in error messages (SwiftUI as an example)
- More info on swift.org
Code completion
- Much better code completion thanks to improvements in SourceKit
- Code completion for dictionary literals, ternary expressions and more dynamic features like key paths
- Code completion in Xcode 12.0 is 15x faster compared to Xcode 11.5
Code Indentation
- Improved indentation formatting in chained methods calls, tuples, multiline if and guards
- Improved indentation in SwiftUI as well
Debugging
- Debugger now displays the reason for Swift runtime failure traps
Cross-Platform Support
- Multiple platform support
  - Apple Platforms
  - Ubuntu 16.04, 18.04, 20.04
  - CentOS 8
  - Amazon Linux 2
  - Windows (coming soon)
- Swift on AWS Lambda
  - Runtime is open-source and is available on GitHub
Language
- Swift Evolution website
- Multiple trailing closure syntax SE-0279
  - It's important to set the correct base name of the method that will indicate the first trailing closure that its label will be dropped
- Key Path Expressions as Functions SE-0249
- @main: Type-Based Program Entry Points SE-0281
  - The standardized way to delegate a program's entry point
- Increased availability of implicit self in @escaping closures when reference cycles are unlikely to occur SE-0269
  - Now it's possible to add self to the capture list
  - In Swift 5.3, if self is a structure it can be omitted entirely from the closure
- Multi-Pattern Catch Clauses SE-0276
- Enum Enhancements
  - Comparable conformance is now synthesized automatically SE-0266
  - Enum cases as protocol witnesses SE-0280
- Embedded DSL Enhancements
  - Builder closures
  - Swift 5.3 introduces pattern matching statements like if let and switch
  - Builder inference (@SceneBuilder is not longer needed)
Libraries
- Float16 SE-0277
  - Half-width floating point type
  - Performance gains but low precision and small range
- Apple Archive
  - Modular archive format
  - Fast compression
  - Idiomatic Swift API
- Swift System
  - Idiomatic Swift interface to system calls
  - Low-level currency types
  - Wraps Darwin APIs
- OSLog
  - Unified logging API
  - Faster and more expressive (formatting options)
- Packages
  - Swift Numerics
    - Support for complex numbers and basic math functions
  - Swift ArgumentParser
  - Swift Standard Library Preview
    - Includes features that have not been included in the release yet

What's new in SwiftUI

https://developer.apple.com/wwdc20/10041

Presenters: Matt Ricketson, Taylor Kelly

Apps
- Bild your whole app using SwiftUI: struct BookClubApp: App
- Apps can declare data dependencies
- Use WindowGroup to manage windows platform independent. Supports multiple windows on macOS and iPadOS out of the bos
- Use Settings to get a preference pane for free • available on macOS
- Use DocumentGroup scene type to automatically handle opening, saving and editing documents • macOS, iOS, iPadOS
- Use CommandMenu command to add additional menus to the menu bar including keyboard shortcuts
- New multi-platform templates specifically for SwiftUI apps
- LaunchScreen Info.plist key to configure your launch screen • simple alternative to the storyboard
Widgets
- iOS, iPadOS, macOS exclusively built using SwiftUI
- Declared by struct YourWidget: Widget and var body: some WidgetConfiguration
- Use SwiftUI to build custom complications for watchOS
Lists and Collections
- List now receive outlines to quickly access the lists content • reduces the need for push/pop navigation patterns
- Lazy loading grid layouts (Lazy[V|H]Stack) to reduce memory footprint and preserve smooth scrolling for large amounts of data
- View Builder for switch statements to show e.g. different image styles in a list of images
Toolbars and Controls
- .toolbar modifier for unified display of toolbars
- Use ToolbarItem(placement: .principal) to make an item prominent
- Use ToolbarItem(placement: .bottomBar) to place an item in the bottom bar
- When using Label("Title", systemImage: "sf.symbol.name") SwiftUI automatically display icon and/or text depending on where the label is displayed: toolbar, list, ...
- .keyboardShortcut modifier can now be used for additional controls like Button
- New default focus support in tvOS
- New controls:
  - ProgressView("Downloading", value: progress) - horizontal bar
  - ProgressView("Downloading", value: progress).progressViewStyle(CircularViewStyle()) - circular progress indicator
  - ProgressView() - spinner
  - Gauge to indicate the level of value • can contain value labels and min/max value labels
New effects and styling
- New control center UI with beautiful transitions
- .matchedGeometryEffect to provide smooth animations inside of a grid of UI elements
- .clipShape(ContainerRelativeShape()) to automatically apply a super views shape to the subview
- custom fonts automatically scaled with dynamic type changes
- Custom accent color directly form the AssetCatalog on all platforms
- Many controls can now be tinted
System integration
- New Link control to display URLs in link style and open them with the default browser • also supports url schemes to open other apps
- @Environment(\.openURL) private var openURL to programmatically open urls via openURL(url) in your views
- onDrag {} and onDrop {} to support drag & drop
- UniformTypeIdentifers framework for e.g. introspection of file types
- Sign in with Apple as first class component in SwiftUI • available on every platform
- Other Frameworks: AuthenticationServices, AVKit, MapKit, SceneKit, SpriteKit

What's new in education

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in location

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in managing Apple devices

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

iPad and iPhone apps on Apple Silicon Macs

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Accelerate your app with CarPlay

https://developer.apple.com/wwdc20/10635

Presenters: Jonathan Hersh, Allen Langmaier

New CarPlay App Possibilites*
- EV charging
- Parking
- Quick food ordering
Audio Apps
- Playable content template will be deprecated
- New audio template
New Templates
- Communication Apps
  - CPMessageListItem
  - Contact template
- List template
- Tab bar template
- Now playing template
- Point of interest template
- Information template
CarPlay Design Principles
- Design for the driver
- Streamline interactions
- Reuse app configuration
- Launch first in CarPlay
- CarPlay apps must adapt UIScene
Updates to development
- Dynamic updates to list elements
- CPListItem
- CPListImageRowItem

Add custom views and modifiers to the Xcode Library

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Advancements in Game Controllers

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

App essentials in SwiftUI

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Bring your Metal app to Apple Silicon Macs

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Broaden your reach with Siri Event Suggestions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build GPU binaries with Metal

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build an Endpoint Security app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build for iPad

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build for the iPadOS pointer

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build with iOS pickers, menus and actions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create a seamless speech experience in your apps

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create app clips for other businesses

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create complications for Apple Watch

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Custom app distribution with Apple Business Manager

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for Game Center

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for intelligence: Apps, evolved

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for intelligence: Discover new opportunities

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for intelligence: Make friends with "The System"

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for intelligence: Meet people where they are

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design great app clips

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design with iOS pickers, menus and actions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Discover Core Image debugging techniques

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Discover HLS Blocking Preload Hints

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Edit and play back HDR video with AVFoundation

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Enable encrypted DNS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Evaluate and optimize voice interaction for your app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore Computer Vision APIs

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore Packages and Projects with Xcode Playgrounds

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore logging in Swift

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore the new system architecture of Apple Silicon Macs

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Export HDR media in your app with AVFoundation

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Get your test results faster

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Handle interruptions and alerts in UI tests

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Handle the Limited Photos Library in your app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Handle trackpad and mouse input

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Harness Apple GPUs with Metal

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Introducing Car Keys

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Leverage enterprise identity and authentication

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Master Picture in Picture on tvOS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet Face ID and Touch ID for the web

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet the new Photos picker

https://developer.apple.com/wwdc20/10652/

Presenters: Tobias Conradi, Justin Jia

PHPicker
- Direct access to user’s photo gallery
  - Supports zoom in, multi-select, review
  - Types are filterable
  - Privacy built in by default
  - It won’t prompt the user for access
  - It runs out of the app’s process
    - Separate process rendered on top of the app
    - Only what user selects is passed back to the app
Implementation
- PHPickerConfiguration (which can include type filters) is passed to PHPickerViewController, which has delegates to handle responses
- PHPickerConfiguration
  - Selection limit
  - Image / Video type
- Initialize PHPickerViewController by using the configuration
  - Set delegate and implement protocol functions
    - didFinishPicking
      - NSItemProvider - representation of the item, async, requires error handling
Demo
- Photo preview app
  - UIImageView with placeholder image
  - Plus button for image selection
    - Present the new picker
  - Create PHPickerConfiguration with images filter and selection limit (set to zero for unlimited selection)
    - Initialize the PHPickerViewController with this configuration
    - Present the new controller after setting delegate and following the protocol
    - Implement didFinishPicking - Dismiss the picker first - Retrieve the image via item provider and use main queue to update your UI
    - Use IndexingIterator<[NSItemProvider]> to save array of item providers
    - Add touch event to iterate through the array of picked images
Note
- AssetsLibrary will go away; switch to PhotoKit
- UIImagePickerController is to be deprecated and replaced with PHPickerViewController

Modernize PCI and SCSI drivers with DriverKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Optimize Metal Performance for Apple Silicon Macs

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Optimize live streams with HLS Playlist Delta Updates

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Secure your app: threat modeling and anti-patterns

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Streamline your app clip

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Support hardware keyboards in your app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Support local network privacy in your app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Swan's Quest, Chapter 2: A time for tones

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Tap into Game Center: Dashboard, Access Point, and Profile

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Tap into Game Center: Leaderboards, Achievements, and Multiplayer

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Visually edit SwiftUI views

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new for web developers

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in CareKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in Wallet and Apple Pay

https://developer.apple.com/wwdc20/10662

Presenter: Stacey Abrams

Use Apple Pay to get into public transit and acadamic buildings
API Enhancements
- PKSecureElementPass replaces PKPaymentPass fom now
- New Apple Pay Button types: .reload , .addMoney, .topUp, .order, .rent, .support, .contribute, .tip
- See how to declare a Apple Pay Button on a website at 2:16
- PKPaymentButton style .automatic automatically switches between light and dark mode
Apple Pay in App Clips
- Could revolutionize everydays payment experience when you can e.g. just tap an NFC tag on a gas station to pay your gas
- Guest checkouts using Apple Pay do not require to setup an account anymore and if it is necessary seamless Sign in with Apple is used.
Enhancing Apple Pay experience across platforms
- Merchants can receive redacted billing address
  - Lower risk of chargebacks for merchnts
  - Price transparency leads to higher conversion rates
- Apple Pay for Catalyst
  - Brings great payment experiences to more mac apps
  - Brings the newly announced APIs, including the Apple Pay button, to the mac
- Improvements in WKWebView will allow more pages to allow Apple Pay transactions now
Contacts Formatting Improvements to prevent invalid shipping addresses
- Street and city fields contain vaild characters only
- State is a two letter code
- US: Zip code is 5 or 9 digit code
- ISO country code is upper case two letter code
- Improved experience when correcting information
  - Raise formatting errors earlier in the payment flow
  - Users can correct information prior to authentication
- Error APIs improved and aligned to new formatting options
- Only rolles out in some Australia, Canada, UK, US for now
Adding cards to Apple Pay
- Issuer Extensions to improve discoverability from within the Wallet app - needs installatioon of an Issuer app
- App requires non-UI extension
  - Extension principal object must subclass PKIssuerProvisioningExtensionHandler
  - Requires non-UI extension entitlement
- Added support for a UI extension
  - Needs to handle re-authentications if required by conforming principal object to PKIssuerProvisioningExtensionAuthorizationProviding
  - Requires UI extension entitlement

What's new in assessment

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in watchOS design

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What’s new with in-app purchase

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Widgets Code-along, part 1: The adventure begins

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Widgets Code-along, part 2: Alternate timelines

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Widgets Code-along, part 3: Advancing timelines

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Adapt ad insertion to Low-Latency HLS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

App accessibility for Switch Control

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Architecting for subscriptions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Author fragmented MPEG-4 content with AVAssetWriter

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Bring keyboard and mouse gaming to iPad

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build Image and Video Style Transfer models in Create ML

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build a SwiftUI view in Swift Playgrounds

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build document-based apps in SwiftUI

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build local push connectivity for restricted networks

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build location-aware enterprise apps

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create Swift Playgrounds content for iPad and Mac

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Debug GPU-side errors in Metal

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Decode ProRes with AVFoundation and VideoToolbox

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Deploy Apple devices using zero-touch

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design for the iPadOS pointer

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Design high quality Siri media interactions

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Discover AppleSeed for IT and Managed Software Updates

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Discover WKWebView enhancements

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Embrace Swift type inference

https://developer.apple.com/wwdc20/10165/

Presenter: Holly Borla

Leveraging type inference
- A type can be inferred by the compiler given the context surrounding a variable or function
- SwiftUI code relies on type inference for reusable views
- A demo is presented showing a SwiftUI component being built using generics
How type inference works in compiler
- Think of type inference as a puzzle
- It resolves the puzzle by filling in the missing pieces using clues from the source code
- Solving one puzzle can give the compiler more clues on how to solve other puzzles
- Type inference errors
  - If a puzzle can't be solved, there's an error in the source code
  - During type inference, the compiler will record information about errors in source code
  - Compiler uses heuristics to attempt to fix errors in order to continue type inference
  - Once type inference is done, the compiler will provide actionable error messages based on collected information (some errors might have auto-fixes)
- Swift 5.3 and Xcode 12 improved error handling a lot, showing more meaningful and reliable error messages
Using Swift and Xcode to fix compile errors
- The compiler will leave breadcrumbs about what the compiler was doing when it found an error
- This can help you connect the dots between the error you're seeing on the editor and other files in your project
- Hold ⌥ + ⇧ on an error breadcrumb and drag it to the right of the source editor, to open the source editor and the breadcrumbs details side by side

Expand your SiriKit Media Intents to more platforms

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Expanding automation with the App Store Connect API

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore numerical computing in Swift

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Explore the Action & Vision app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Gain insights into your Metal app with Xcode 12

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Get the most out of Sign in with Apple

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Getting started with HealthKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Improve stream authoring with HLS Tools

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Keep your complications up to date

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Make apps smarter with Natural Language

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Meet Audio Workgroups

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Optimize Metal apps and games with GPU counters

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Optimize the interface of your Mac Catalyst app

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Reduce Latency with HLS Blocking Playlist Reload

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Stacks, Grids, and Outlines in SwiftUI

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Support performance-intensive apps and games

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Swan's Quest, Chapter 3: The notable scroll

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Sync a Core Data store with the CloudKit public database

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

The Push Notifications primer

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

The artist’s AR toolkit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Triage test failures with XCTIssue

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Unsafe Swift

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in ClassKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in Core NFC

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in ResearchKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in USD

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

What's new in streaming audio for Apple Watch

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Write tests to fail

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

XCTSkip your tests

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Accessibility design for Mac Catalyst

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Add configuration and intelligence to your widgets

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Advancements in the Objective-C runtime

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

AutoFill everywhere

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Background execution demystified

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Become a Simulator expert

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Beyond counting steps

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Boost performance and security with modern networking

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build SwiftUI views for widgets

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build customized ML models with the Metal Performance Shaders Graph

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build localization-friendly layouts using Xcode

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Build scalable enterprise app suites

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Capture and stream apps on the Mac with ReplayKit

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Control training in Create ML with Swift

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Core Data: Sundries and maxims

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create custom apps for employees

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Create quick interactions with Shortcuts on watchOS

https://developer.apple.com/wwdc20/`insert-session-number-here`

Presenters: Example Guy, Another Person

// TO-DO! You can contribute to this session, please see CONTRIBUTING.md

Data Essentials in SwiftUI

https://developer.apple.com/wwdc20/10040

Presenters: Curt Clifton, Luca Bernardi, Raj Ramamurthy

Getting Started
- Always ask you the following questions:
  - What data does my view need?
  - How will the view manipulate this date?
  - Where will the data come from?
- Immutable views, that just display data, contain only let properties
- Pull multiple properties in their own config object
  - The config object can contain functions to mutate its state
  - Using @State private var config: ConfigObject() to re-render your view after config changed
  - Let parent and sub views communicate over a single config object by sharing it using @Binding var config
  - Pass config down by marking the it as reference using the dollar symbol: SubView(config: $config)
Modeling Data Using ObservableObject
- Class-constrained protocol (only adoptable by reference types)
- Can be used to achieve super-custom behaviors, e.g. backing data by a service or server
- Conform by implementing var objectWillChange: Self.ObjectWillChangePublisher { get }
- Use to manage data life cycle, handle side-effects, integrate with existing components
- Will be your source of truth
- Doesn't need to be your full data model - split into multiple observable objects if your model is complex
- Use a single ObservableObject for all your views if your data model is simple
- Mark properties of your ObservableObject, your view is interested in as @Published var progress: Double
- How to create an ObservableObject dependency?
  - @ObservedObject
    - @ObservedObject var config: Configuration
    - You need to manage the objects ownership outside of your view
    - Create a binding to any value-type property of the ObservableObject to pass it into e.g. $config.isFinished a Toggle control and let it automatically update your view
  - @StateObject
    - SwiftUI owns the ObservableObject
    - Creation/destruction is tied to view's life cycle
    - Instantiated just before body runs
    - Use it to implement e.g. an ImageLoader: ObservableObject with a @published var image: Image property
    - Whenever @StateObject changes the view is re-rendered and thus populated with the image
  - EnvironmentObject
    - In SwiftUI you typically have a hierarchy of many modular sub views
    - To avoid a lot of boilerplate by passing around ObservableObject's pass it to .environmentObject(...) on your root view
    - Changes to it, from any view in the hierarchy, will be reflected in any other view
SwiftUI Performance Considerations
- Avoid slow view updates
  - Make view initializers cheap, e.g. no dispatches
  - Make body a pure function
  - Avoid assumptions
- New event sources: onChange, onOpenURL, onContinueUserActivity - run on main thread
Who owns the data?
- Share data in a common ancestor
- Leverage @StateObject
- Consider placing global data in App and pass it down the view hierarchy. Changes to it will re-render all scenes (instances/windows) of your app
- New 2020: Property Wrappers that offer data persistence across app restarts and can be used as source of truth
  - @SceneStorage
    - Per-scene property wrapper for reading/writing data managed by SwiftUI
    - Light-weight storage for your views data
    - Use it to populate your collection views
  - @AppStorage
    - App-scoped global storage, persisted using UserDefaults, usable anywhere (app/view)
    - Perfect for storing settings
    - @AppStorage("amountOfGold") private var amountOfGold = 5000
    - Automatically reads/writes from/to UserDefaults whenever the property changes