Sonoma 14.5, Xcode 16.0 (16A242d)
Pure SwiftUI application, MacOS (document-based), a single TextView with a binding instead of the template solution with added UndoManager functionality (which seems unnecessary).
The error does not happen every time:
– if I type in an existing document, it's fine; if I switch to Xcode and back to my app, the error appears.
– if I create a new document and select the existing string, it's fine. If I create a second new document and select the string in that, I get the error.
– if I switch between two dirty unsaved documents, I get the error.
and so on. I'm reasonably confident there are patterns to this, but I don't have the time or patience to try all of them.
green_knight
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This was driving me mad as well, because half the examples (including in this state answer 'how do I preview a @Binding' with 'here's a working example using @State' which misses the point by a mile. I've found different workarounds elsewhere that also didn't work for me.
What does work, however, is to replace @Binding with @Bindable. And suddenly, the standard
#Preview macro works out of the box.
#Preview {
BindingViewExample_2(value: true)
}
I had this problem with trying to create an NSImage from a URL retrieved from an openDialog (well, a SwiftUI .fileImporter) even after setting the UserSelectedFile Sandbox permission. (If it's 'none', it'll crash, so it's hard to get that one wrong).
The fileImporter retrieves a valid URL, but cannot access the file anyway. (This used to work).
The answer is to make the resource explicitly accessible:
_ = selectedFileURL.startAccessingSecurityScopedResource()
guard let image = NSImage(contentsOf: selectedFileURL) else { return } selectedFileURL.stopAccessingSecurityScopedResource()
In Xcode 16b the first error is slightly rephrased:
BOOL _NSPersistentUIDeleteItemAtFileURL(NSURL *const __strong) Failed to stat item: file:///Users/username/Library/Containers/appIdentifier/Data/Library/Saved%20Application%20State/appIdentifier.savedState/restorecount.plist
and every app, including Apple examples has it.