When the SwiftUI announcement came out at WWDC 2019, you were buzzing about the new framework. Finally, a new way to build our interfaces. Out with ViewControllers, out with storyboards, in with declarative, programmatic UIs!
Now that we’ve all had some time to play with the framework, we’ve found out what we’re really trading away when we use SwiftUI, at least for now. One of the major things? The vast array of components and configurability available through UIKit.
You’ve probably found through experimenting with the new framework that there are things missing. Entire UIKit components are missing, and things like the broad number of properties you could set on TextFields, and the common pull-to-refresh control are missing.
You really don’t want to continue down the UIKit road. You want to go all in on SwiftUI now; it’s the future of development for all Apple platforms. “But how am I going to get back these features?”
This is where
UIViewRepresentable comes in. Apple knew that SwiftUI was not going to be a complete port of UIKit for its first version, and so they provided this protocol which you can implement on a View struct to wrap a UIKit control, making it usable in SwiftUI. Let’s see an example how to use this: getting the pull-to-refresh functionality on a scroll view.