Hacking with Swift Live 2021

My Xcode projects and sources created during Hacking With Swift Live online-workshops hosted by @twostraws.

Day 1

• Various Swift 5.5 features and additions: Check out the code ContentView.swift

• Message Inbox: Learning about the new basic concurrency features: async and await keywords, SwiftUI .task modifier (as alternative to .onAppear), async let assignment and Task struct to run/submit parallel tasks

• Practice Petitions: Writing a small app showing "petitions" fetched and decoded using the new concurrency approach

• Practice Chat Messages: Writing an app downloading 3 independent JSON data files and displaying them using SwiftUI

Day 2

• Message Inbox: Learning more about the concurrency features: Task suspend, cancellation, sleep, TaskGroup. Read the code in ContentView.swift

• Practice News Stories: Writing a small app showing news stories fetched from 5 JSON feeds, concatenating and sorting for display.

• Heterogenous TaskGroups: How to handle tasks within a TaskGroup returing different types? Wrap the result in an enum! Read the code in ContentView.swift

• Practice TaskGroup: Writing a asynchonous loadData method fetching data from different locations and of different types, combining the result before updating the views model. Read the code in ContentView.swift!

• Actor: What is an actor and its purpose? Simple examples in ContentView.swift: URLCache, BankAccount, BasketballTeam and Player. Handling Hashable and Codable for actors, when to use nonisolated and isolated keyword and how global actors, the MainActor fit into the picture.

  Bonus: Using Task.detached to run code parallely not bound to the same actor which the View might inherit from its properties!

• Bus+: new features in SwiftUI so far AsyncImage, .task modifier (to be continued on day 3!)

Day 3

• AsyncSequence: This session was an introduction to AsyncSequence hosted by Daniel H Steinberg. First reminder about Sequence and Iterator protocol and conformance, then introducing asynchronicity by using notifications (and the new Notification sequence which conforms to AsyncSequence), implementing own data model using AsyncSequence and AsyncIterator, finally using AsyncStream.

• Bus+: illustrating more new features of SwiftUI

  • refreshable to reload busses list with a "pull to refresh" gesture
  • searchable to allow searching/filtering the list of busses
  • Adding swipeActions for "Add favorite" button
  • tinting list row separators and using a few new colors indigo, mint and cyan
  • using foregroundStyle to add a gradient drawing to a SF symbol
  • using symbolRenderingMode to draw SF symbols hierarchically
  • using Markdown styling for Text rendering
  • using ultraThinMaterial to have a blured background when a bus has been selected
  • using focused modifier, submitLabel and onSubmit to implement a User input form with automatic input focussing.
  • adding "Next" and "Done" buttons to keyboard toolbar (using ToolbarItemGroup(placement: .keyboard))
  • illustrating ObservableObject using @MainActor to validate some user data
  • adding a badge modifier to a tabItemto highlight missing user input
  • Bonus: generating a QR code from user provided data (using CoreImage CIFilter)
  • Bonus: using Mirror to introspect Bus type for improved search completion