I am building a document based SwiftUI macOS app and I can't find a way to turn this off. I don't ever want to edit or save over the original file (and I don't wan't to duplicated the original either).

I've tried a bunch of hints from others and none work or are hacks that only half work

I have tried to set the app as only 'viewing' mode as per Apple documentation: DocumentGroup(viewing:

somewhere suggested that this might work as set via delegate (doesn't do anything - haven't tried a negative delay or a million seconds yet) NSDocumentController.shared.autosavingDelay = 0

In fileWrapper, I can throw a random error but this still gets called (just wont overwrite file since not returning new data -- also it presents messsaging to the user of error - if I could throw some other error silently, might be OK) throw CocoaError(.fileWriteNoPermission)

The whole point of the app if to safely crop/edit/greyscale JPEGs without any image re-sampling (it is a front end to JPEGTRAN command line). But it defeats the purpose to overwrite the original file.

Would hate to have to re-write as a non-document based app.

Found a workable solution – I think ( requires using Document as a class vs a struct )--

https://stackoverflow.com/questions/44161308/prevent-nsdocuments-auto-saving-while-its-content-is-editing

Use documents as class vs.[valve-cover-gasket]