Sample project not loading photos on iOS 4.2.1

[djrossi]

The navigation bar continues to say "Loading..." and it never retrieves the photos from the library. It works fine in the simulator.

[djrossi]

I just found out that you need to enable location services to access the user's photo library. After enabling core location, all of the photos loaded as expected.

[mike-bytes]

I'm having the same problem even after enabling location services (Settings->General->Location Services->On) on my iOS 4.2.1 device. Anyone find an alternative solution to this?

[djrossi]

You have to enable location services for your application, and ask for permission from the user. Enable location services in the settings application will not solve it.

[mike-bytes]

Thanks for the reply. I googled for a while and found the reason: it appears that [ALAssetsLibrary enumerateGroupsWithTypes:] fails if it is executed on a thread that is not the main thread. Enclosing the function in dispatch_async(dispatch_get_main_queue() seems to solve the bug.

The details are documented here:
https://devforums.apple.com/message/323036#323036
and
http://stackoverflow.com/questions/4200552/assets-library-framework-not-working-correctly-on-4-0-and-4-2