Detect overwritten file using NSDocument
cocoa, macos, nsdocument
Solution
`NSDocument` implements the NSFilePresenter protocol out of the box. You can override `presentedItemDidChange` to update automatically when the file has changed.
Problem
I have an OSX app which uses NSDocument and autosaves inplace - all works well. Sometimes the user will save the document into a Dropbox synced folder and there is then the chance that the document will be updated (via Dropbox) whilst its still open in the app. Question is, how do I detect this and reload the document from disk (or at least inform the user.) Thanks