I am getting this error in my preview:
CompileDylibError: Failed to build ContentView.swift
Compiling failed: main actor-isolated let 'previewContainer' can not be referenced from a non-isolated context
I don't know enough about @MainActor to figure this out.
Yes, this is a known issue. You can work around it as suggested by using MainActor.assumeIsolated:
#Preview {
MainActor.assumeIsolated {
ContentView()
.frame(minWidth: 500, minHeight: 500)
.modelContainer(previewContainer)
}
}
Hey, Developer Tools Engineer, Julia is an excellent presenter! If you see her, could you please correct her pronunciation of "model"? She makes it sound like "modal", which was a bit distracting. And give her a thumbs up for her good teaching style.
This looks like an issue with some aspect of the #Preview macro implementation.
I replaced it with the old-style preview syntax and bypassed this issue:
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
.modelContainer(previewContainer)
}
}
"I encountered the same issue in Xcode 15.0 beta, SwiftDataExample, and I was able to resolve it using this method."
I kept the #Preview macro by changing it to this, but with warnings about losing global actor 'MainActor':
#Preview { @MainActor in
ContentView()
.frame(minWidth: 500, minHeight: 500)
.modelContainer(previewContainer)
}
@Apple, is this a bug in this early beta stage or will the sample code be modified to get around this behavior ?
I asked Chatgpt for this question, and it told me this: #Preview { MainActor.assumeIsolated { ContentView() .frame(minWidth: 500, minHeight: 500) .modelContainer(previewContainer) } } It worked.
This did it for me, thanks so much.
Yes, this is a known issue. You can work around it as suggested by using MainActor.assumeIsolated:
#Preview {
MainActor.assumeIsolated {
ContentView()
.frame(minWidth: 500, minHeight: 500)
.modelContainer(previewContainer)
}
}
Hey, Developer Tools Engineer, Julia is an excellent presenter! If you see her, could you please correct her pronunciation of "model"? She makes it sound like "modal", which was a bit distracting. And give her a thumbs up for her good teaching style.
Thanks!!