Forcing a saved image to sync with the iCloud Photo Stream

Question

I have an app that takes images periodically, and I would like them to be uploaded to the iCloud Photo Stream right after the images are taken.

It appears that certain conditions need to be met in order for this to work. It only seems to work when running iOS 8, the device is connected to wireless, and by using UIImagePickerController to take pictures (rather than AVCapture) at least once. It seems that the UIImagePickerController when presented alters some system settings that allows for subsequent automatic uploading of images to the iCloud Photo Stream. If I use AVCapture only to take pictures, it will not work. I've confirmed that "Upload to My Photo Stream" is enabled in the iCloud settings, and there is an active wireless connection.

Here is the method used to save an image obtained from UIImagePickerController:

- (void)saveImage : (UIImage *)image {
    // Add image to the photo library
    [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        PHAssetChangeRequest *assetChangeRequest =
        [PHAssetChangeRequest creationRequestForAssetFromImage:image];
    } completionHandler:^(BOOL success, NSError *error) {
        if (!success)
            NSLog(@"Error creating asset: %@", error);
    }];
}

When running on my iPad with iOS 8, below are the entries that I see in the device system logs:

Oct 22 21:11:06 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Submitting 1 asset collections for publication.
Oct 22 21:11:06 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
Oct 22 21:11:10 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx uploading 1 assets...
Oct 22 21:11:11 iPad mstreamd[14409] <Notice>: (Note ) PS: Received push notification for invitations topic: com.apple.mediastream.subscription.push userInfo: {
        r = xxxxxxxx;
    }
Oct 22 21:11:11 iPad mstreamd[14409] <Notice>: (Note ) PS: <MSIOSMediaStreamDaemon: 0x1662ad80>: Push notification received for My Photo Stream with targetPersonID xxxxxxxx.
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x1666fae0>: Plugged in to external power. Allowing file transfers.
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x1666fae0>: Push received. Allowing file transfers to continue for 60.00 seconds
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
Oct 22 21:11:12 iPad mstreamd[14409] <Notice>: (Note ) PS: MSSubscriber - xxxxxxxx Found 1 new asset collections.
Oct 22 21:11:13 iPad assetsd[11536] <Warning>: Unable to open file to save extended attributes (No such file or directory).

When running on my iPhone with iOS 9.1, I have similar log entries, except I have additional warnings/error messages about the caching server bolded:

Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Submitting 1 asset collections for publication.
Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...
**Oct 25 22:35:28 iPhone AssetCacheLocatorService[1658] <Warning>: #df99fdd0 [I:AssetCacheLocatorService.queue] found no caching servers**
Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx uploading 1 assets...
**Oct 25 22:35:28 iPhone mstreamd[1735] <Notice>: (Error) mmcs: __mmcs_proxy_locator_exists_block_invoke:167 might have caching server returned with error: Error Domain=NSPOSIXErrorDomain Code=60 "Operation timed out" UserInfo={com.apple.AssetCacheLocator.tag=#1963bd2d, NSLocalizedDescription=quick miss requested}**
**Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSPublisher - xxxxxxxx Sending metadata...**
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: Received push notification for invitations topic: com.apple.mediastream.subscription.push userInfo: {
        r = xxxxxxxx;
    }
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: <MSIOSMediaStreamDaemon: 0x157e0c530>: Push notification received for My Photo Stream with targetPersonID xxxxxxxx.
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x157e84410>: Plugged in to external power. Allowing file transfers.
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) mstreamd: <MSPowerBudget: 0x157e84410>: Push received. Allowing file transfers to continue for 60.00 seconds
Oct 25 22:35:29 iPhone mstreamd[1735] <Notice>: (Note ) PS: MSSubscriber - xxxxxxxx Found 1 new asset collections.
Oct 25 22:35:30 iPhone assetsd[1624] <Warning>: Unable to open file to save extended attributes (No such file or directory).

In this situation with iOS 9, the image is not uploaded when my app is active, and is uploaded only when the app goes into the background.

I suspect that the issue is due to 1. some system setting that is is activated with presentation of the UIImagePickerController only in iOS8 or 2. some issue with caching servers in iOS 9 as suggested by the log entries.

Anyone have any idea what is going on? Any ideas would be greatly appreciated! Thanks!

Answer 1

I think I've found a solution. It seems that if an AVCaptureSession is running, the iCloud Photo Stream will not synchronized. Calling the stopRunning method (as below) seems to do the trick:

[self.cameraSession stopRunning];