如何在不将其备份到iCloud的情况下通过我的应用程序提供演示数据？

Question

I have an app in the App Store since January, that copies a database file to the "Documents" directory at first launch.

This database is used to store "presets", created by users. Each preset can have up to 129 photos.

At start, the app comes with a "default preset", that users can use to understand and start to use the app. This preset is like a "gift" to the user, and if he doesn't want it anymore, he can just delete it.

On update 2.0.2 nothing was changed in this schema, but Apple rejected my update now.

2.23 - Apps must follow the iOS Data Storage Guidelines or they will be rejected

I can't figure out how I can solve this. The issue seems to be that the default preset, which Apple considers "temporary" gets backed up to iCloud. This preset is NOT temporary. It must persist, and is part of the database.

I also can't mark the database with the "do not back up", because this way the "presets" created by the users won't be backed up, which would be terrible.

Anybody have an idea how to solve this?

Answer 1

You need to flag the file to not backup to iCloud .

Without flagging the file as such, it will be eligible to backup to iCloud. Apple has recently began to enforce this.

If the app generates a lot of data, on app startup, they'll reject it. Apple's reasoning for this is that any data that can be regenerated should not be backed up to iCloud.

To prevent this, Apple recommends:

- (BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL
{
    assert([[NSFileManager defaultManager] fileExistsAtPath: [URL path]]);

    NSError *error = nil;
    BOOL success = [URL setResourceValue: [NSNumber numberWithBool: YES]
                                  forKey: NSURLIsExcludedFromBackupKey error: &error];
    if(!success){
        NSLog(@"Error excluding %@ from backup %@", [URL lastPathComponent], error);
    }
    return success;
}

Other than that blanket omission from iCloud, the only thing you're left with is separating your user generated content from your re-creatable content .

Answer 2

"do not back up" is a file-level attribute. So perhaps mark only your "gift" files with that attribute?

Answer 3

Unfortunately, the guidelines are pretty clear on this -- only user generated data may be stored in the Documents directory and backed up to iCloud.

However, it looks like you can prevent specific files from being backed up: https://developer.apple.com/library/ios/qa/qa1719/_index.html#//apple_ref/doc/uid/DTS40011342

You are going to have to find a way to separate your preset data from the user's data store and mark the preset data as "do not back up"

Answer 4

I faced that same problem with one of my apps. I had to generate another version of my database and store it into the Caches folder, and mark it as not eligible for iCloud backup. Then store all user generated content into another database in the documents folder, which actually gets backed up to iCloud.