Should I use UIKit or SwiftUI?

When deciding between UIKit and SwiftUI, there are several factors to consider based on the content presented at WWDC:

1. Ease of Use and Learning Curve:

   • SwiftUI: SwiftUI is designed to be easy to learn and use, with a declarative syntax that allows you to describe the UI you want and let SwiftUI handle the details. This can lead to less code and faster development times. It is particularly well-suited for new projects or when adding new features to existing apps (Platforms State of the Union).
   • UIKit: UIKit is an imperative, object-oriented framework that has been around for a long time and provides rich capabilities. It might have a steeper learning curve compared to SwiftUI, especially for new developers (SwiftUI essentials).

2. Interoperability:

   • SwiftUI: SwiftUI offers seamless interoperability with UIKit and AppKit. You can use UIViewRepresentable to integrate UIKit views into SwiftUI and HostingViewController to embed SwiftUI views into UIKit (SwiftUI essentials).
   • UIKit: If your app already heavily relies on UIKit, you can incrementally adopt SwiftUI for new features without needing to rewrite the entire app (SwiftUI essentials).

3. Advanced Features and Customization:

   • SwiftUI: SwiftUI provides a wide range of built-in capabilities and allows for advanced customizations using modifiers and protocols. It also supports custom animations, containers, and more (Platforms State of the Union).
   • UIKit: UIKit offers longstanding rich capabilities and might be more suitable for apps that require very specific or complex UI customizations that are not yet fully supported by SwiftUI (SwiftUI essentials).

4. Platform Support:

   • SwiftUI: SwiftUI is designed to work across all Apple platforms, making it easier to share code and create a consistent experience on iOS, macOS, watchOS, tvOS, and visionOS (SwiftUI essentials).
   • UIKit: While UIKit is primarily for iOS, it has its counterpart AppKit for macOS. If you are targeting multiple platforms, SwiftUI might offer a more streamlined approach.

In summary, if you are starting a new project or adding new features, SwiftUI is highly recommended due to its ease of use, modern syntax, and cross-platform capabilities. However, if you have an existing UIKit-based app, you can incrementally adopt SwiftUI where it makes sense, leveraging its interoperability features.