Adding the “Do Not Backup” attribute to a folder hierarchy in iOS 5.0.1

Question

Referencing iCloud + Storage of media in iPhone Documents folder, which shows how to set the iOS 5.0.1 \"Do Not Backup\" attribute for a file.

Is there an efficient

Answer 1

For all my friends here, who needs in Swift - just look below (iOS8.0)

func addSkipBackupAttributeToItemAtURL(URL:NSURL) ->Bool{

let fileManager = NSFileManager.defaultManager()
assert(fileManager.fileExistsAtPath(URL.absoluteString))

var error:NSError?
let success:Bool = URL.setResourceValue(NSNumber.numberWithBool(true),forKey: NSURLIsExcludedFromBackupKey, error: &error)

if !success{

    println("Error excluding \(URL.lastPathComponent) from backup \(error)")
}

return success;

}

Answer 2

For me, in Swift, the previously answered functions didn't quite work. In particular the assert line failed. I needed to update it from URL.absoluteString! to URL.path! So in the end mine looks like this:

func addSkipBackupAttributeToItemAtURL(URL:NSURL) ->Bool{

    let fileManager = NSFileManager.defaultManager()
    assert(fileManager.fileExistsAtPath(URL.path!))

    var error:NSError?
    let success:Bool = URL.setResourceValue(NSNumber(bool: true),forKey: NSURLIsExcludedFromBackupKey, error: &error)

    if !success{
        println("Error excluding \(URL.lastPathComponent) from backup \(error)")
    }

    return success;
}

Answer 3

you can do the following in swift:

func addSkipBackupAttributeToItemAtPath(path:String) -> Bool {


    let filePath = path.fileSystemRepresentation()
    let attrName  = "com.apple.MobileBackup"

    var attrValue : uint_fast8_t = 1

    let result = setxattr(filePath, attrName, &attrValue, sizeof(attrValue.dynamicType), 0, 0)

    return result == 0
}

Answer 4

Correction on above method,use this for swift

 func addSkipBackupAttributeToItemAtURL(URL:NSURL) ->Bool {

    let fileManager = NSFileManager.defaultManager()
    assert(fileManager.fileExistsAtPath(URL.absoluteString!))

    var error:NSError?
    let success:Bool = URL.setResourceValue(NSNumber(bool: true),forKey: NSURLIsExcludedFromBackupKey, error: &error)

    if !success{

        println("Error excluding \(URL.lastPathComponent) from backup \(error)")
    }

    return success;
}

Answer 5

You could put one specific directory inside the documents dir for this purpose, put everything inside and only mark that single directory as do-not-backup using the

 addSkipBackupAttributeToItemAtURL

method shown in the article you linked, or use this one that uses a path instead of an URL:

+ (void)addSkipBackupAttributeToPath:(NSString*)path {
    u_int8_t b = 1;
    setxattr([path fileSystemRepresentation], "com.apple.MobileBackup", &b, 1, 0, 0);
}

example using a directory:

NSString *docsDirPath = [(AppDelegate*)[[UIApplication sharedApplication] delegate] applicationDocumentsDirectory];
NSString *yourContentsDirPath = [docsDirPath stringByAppendingPathComponent:gContentsDirName];

[Utilities addSkipBackupAttributeToPath:yourContentsDirPath];

[EDIT]

I forgot this method use in the delegate to get the documents dir:

- (NSString *)applicationDocumentsDirectory {

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
    return basePath;
}

Answer 6

maybe this would help someone using swift 2:

Just before @UIApplicationMain add this:

extension NSFileManager{
    func addSkipBackupAttributeToItemAtURL(url:NSURL) throws {
        try url.setResourceValue(true, forKey: NSURLIsExcludedFromBackupKey)
    }
}

In your lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = { after you declare your URL you can add this:

 do {
            let url = url
            try NSFileManager.defaultManager().addSkipBackupAttributeToItemAtURL(url)

        } catch {
            // Handle error here
            print("Error: \(error)")
        }