SwiftUI: Declarative GUIs for Mobile and Desktop Applications

Modern graphical user interfaces typically require a complex balancing act of managing view state, during asynchronous user interactions, while the model state of the application may change concurrently; e.g., due to network activity. This necessitates a complex dance of coordinating UI view updates and event handlers, while trying to ensure that the view state always accurately reflects the application’s model state and that no user input gets lost.

Declarative user interfaces promise to automate much of this complexity by automatically and efficiently rendering the user interface on the basis of the current model state, thus freeing the programmer from manually tracking all dependencies leading to state and view updates. SwiftUI is Apple’s contender at realising this dream for complex mobile and desktop applications.

In this tutorial, I will show you how SwiftUI works and we will build an application together. I will explain views, view modifiers, bindings, observable models, previews, and more.

To participate in this tutorial, you will need a Mac as we will make use of the Xcode IDE. However, you don’t need to know Swift. If you are familiar with Kotlin or Scala, or even just modern Java with some functional programming, I will explain the rest.

To code along, please make sure to bring a Mac with macOS Sonoma and the latest version of Xcode (i.e., Version 15.3), which is freely available from the Mac App Store.

Manuel Chakravarty

Twitter: @TacticalGrace

Manuel M T Chakravarty is a researcher and software developer with interests in programming languages, cryptography, and programming environments. He developed the interactive development environment Haskell for Mac — one of the first Swift apps on the Mac App Store. He is now working on the successor of Haskell for Mac, which leverages SwiftUI for cross-platform development. His current research work lies at the intersection of programming languages and cryptography with applications to open blockchains. Recent contributions cover smart contract and native asset support for UTxO ledgers, such as Cardano, as well as multi-party state channels. He has also published extensively on programming languages, compilers, and high-performance computing. He contributed to both the design and implementation of the Haskell programming language (most notably, type families, associated types, and the foreign function interface) as well as several Haskell tools and open source libraries. He is currently a functional programming expert at Tweag and a researcher & architect of smart contract technology at IOG (formerly, IOHK). Before that he was an Associate Professor at UNSW Sydney.