I have been developing iOS for about a decade and every time I try to take the dive into SwiftUI I spend more time than ever wrestling what should seemingly be a simple task. While working on an app with very simple navigation setup I kept seeing two errors in the console: Unable to present. Please file a bug. and Unbalanced calls to begin/end appearance transitions for <_TtGC7SwiftUI19UIHostingControllerGVS_15ModifiedContentVVS_22_VariadicView_Children7ElementGVS_18StyleContextWriterVS_19SidebarStyleContext___: 0x7fd913d0bd90>. The first happens when there are at least 3 Views to navigate from (I don't understand why this is a significant threshold and my end goal uses a LazyVGrid with a ForEach) with navigation links and the second error happens on rotating to landscape and then back to portrait. I believed this to be related to how the phone is presenting the sidebar but even changing to StackNavigationViewStyle produced similar problems.
If this were a UIKit application I can absolutely solve for the Unbalanced calls situation but SwiftUI really takes away some of the lower level capabilities that I am used to having control of when it comes to building Views and navigation stacks.
I finally attempted to just start a new project from scratch and place the minimal amount of code in the ContentView:
struct ContentView: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: Text("Number 1")) {
Text("Number 1")
}
NavigationLink(destination: Text("Number 2")) {
Text("Number 2")
}
NavigationLink(destination: Text("Number 3")) {
Text("Number 3")
}
}
}
}
}
Running the above code produced the issues on rotation. Another issue that I came across was when you press the < back button after these issues start, the navigation stops working completely and the "detail" view never gets updated.
It is clear that the direction is SwiftUI so I am trying to really go this direction (maybe next week will have some amazing improvements) but this seems to be a pretty significant issue on a very simple set of code. I am hoping that I am just doing something wrong that someone can point out quickly.
EDITED:
After more exploration I found that the second error happens on the 11, 11 Pro Max, and 12 Pro Max where the navigation stack changes to the sidebar by default. Changing the style to StackNavigationViewStyle does eliminate the second error (but doesn't help if I do want to use the sidebar style) but the first error remains. To Schottky's point, changing VStack to List will also eliminate the first error. However a newer convention (based on WWDC videos at least) to solve for collection views I believe is to use a LazyV/HGrid with a ForEach within it which is actually what I am attempting to accomplish. I didn't put that as my code here since I wanted the be able to reproduce the error in the simplest form of course to ensure it wasn't something buried in my view hierarchy.