How to rollback the change in modifyItem in macOS FileProvider Extension?

Question

Let's say user renames a file/folder in FileProvider extension. modifyItem callback is invoked where we issue a rename request to the server. Server responds with an error (ie user doesn't have permission to rename the relevant file/folder). We invoke the completionHandler with error code, but the renamed file/folder will remain in the file system.

What is the best way to revert file/folder name to the original one (before the rename attempt)?

Simplified code would ideally be something like:

func modifyItem(_ item: NSFileProviderItem, baseVersion version: NSFileProviderItemVersion,
                    changedFields: NSFileProviderItemFields, contents newContents: URL?,
                    options: NSFileProviderModifyItemOptions = [], request: NSFileProviderRequest,
                    completionHandler: @escaping (NSFileProviderItem?,
                                                  NSFileProviderItemFields, Bool, Error?) -> Void) -> Progress {

    let node = localDatabase.getNode(item.id)
    let originalFilename = node.filename
    node.filename = item.filename

    let result = server.performRename(item.filename)

    if result == false {
        // TODO: revert item to original filename
        node.filename = originalFilename
        let retItem = node.item()
        completionHandler(retItem, [], false, NSError(domain: NSFileProviderErrorDomain, code: NSFileProviderError.Code.cannotSynchronize.rawValue, userInfo: [:]))
    }else{
        let retItem = node.item()
        completionHandler(retItem, [], false, nil)
    }
}

But this doesn't revert the file/folder filename value, it just shows file/folder in Finder with cloud-error icon that upsync failed. But I would also like to revert the renamed file/folder to the original value.

Answer 1

I suppose you will have to signal about the change in the working set and then subsequently provide the deleted and added item when requested.