ITLibrary gives me nothing but (null)

Question

My program automates a radio station. There is lots of communication back and forth between it and iTunes. I programmed it with scripting bridge. Scripting bridge suffers from memory leaks. Each call to scripting bridge leaks a small amount of memory. Add a lot of calls to a program that runs 24/7 and I've got software that will run for something less than 24 hours, and then quit.

My first attempt at a solution was to minimize my calls to scripting bridge. In researching that end, I came across ItunesLibrary. It isn't working for me.

NSError *error = nil;
ITLibrary *library = [ITLibrary libraryWithAPIVersion:@"1.0" error:&error];
if (library)
{
    NSArray *playlists = [[NSArray alloc]init];
    playlists = library.allPlaylists;
    NSArray *tracks = [[NSArray alloc]init];

    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"mediaKind == %d", ITLibMediaItemMediaKindSong];
    tracks = [library.allMediaItems filteredArrayUsingPredicate:predicate];

    NSLog(@"Playlists - %@",playlists);
    NSLog(@"Tracks - %@",tracks);
}

This code is pretty much right out of Apple's docs. It should work - I think.

Before I added the predicate, I got some info on each of the podcasts in my iTunes library. In the nslog output, each of my playlists produces an entry similar to "". Each of my songs shows nothing more than (null).

All of the info is in iTunes. I can read it with scripting bridge. I can read it with AVAsset

AVAsset *asset = [AVURLAsset URLAssetWithURL:myUrl options:nil];

NSArray *metadata = [asset commonMetadata];
for ( AVMetadataItem* item in metadata )
{
    NSString *key = [item commonKey];
    NSString *value = [item stringValue];
    NSLog(@"key = %@, value = %@", key, value);
}

With AVAsset I only get the song name, album name, and artist name. I need to access the rest of iTune's ID3 tags.

What have I don to break ItunesLibrary?

Answer 1

The secret to getting ItunesLibrary to work seems to be in the entitlements file. You need to add the key "com.apple.security.assets.music.read-only", and set it to YES. I got this by digging through a project on github.com.