NSArray exception when adding track to starred playlist - ios

Question

Sometimes, I'm getting a fatal exception when trying to "star" a track in cocoalibspotify. I'm logging in with a user with a heavy dataset (hundreds of playlists, but < 15 starred tracks).
This is how I "star" the SPTrack:
[[[[SPSession sharedSession] starredPlaylist] items] addObject:myTrack];
... and the stack trace:
*** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSArray objectsAtIndexes:]: index 12 beyond bounds [0 .. 11]'
*** Call stack at first throw:
(
0 CoreFoundation 0x01e125a9 __exceptionPreprocess + 185
1 libobjc.A.dylib 0x021a1313 objc_exception_throw + 44
2 CoreFoundation 0x01da0f99 -[NSArray objectsAtIndexes:] + 633
3 Foundation 0x016a250b -[NSKeyValueArray objectsAtIndexes:] + 110
4 Foundation 0x016aaca6 NSKeyValueDidChangeByArrayMutation + 103
5 Foundation 0x01610c30 NSKeyValueDidChange + 266
6 Foundation 0x016aba95 -[NSObject(NSKeyValueObserverNotification) didChange:valuesAtIndexes:forKey:] + 123
7 Foundation 0x016a4d0e -[NSKeyValueNotifyingMutableArray addObject:] + 239
8 MyApp 0x000922cd -[PlaylistManager starTrack:] + 285
...
This only seems to happen within a minute or two after logging in (i.e. user data is loaded), so I'm guessing it might be an issue where the data isn't fully loaded or something?
I've tried to find out if there's any properties to observe in order to find out when everything's fully loaded. But as the array might be empty (and the user might not have starred any tracks before), it seems like there's no good way of validating that everything's loaded...? The loaded property of SPPlaylist seems to refer to the playlist metadata, and not its tracks (?).
Any ideas?

Answer 1

You are getting the So it looks like you're not supposed to manipulate that array directly. Instead call [myTrack setStarred:YES];
Basically, I just went through the entire Spotify API for you to find that answer.

Answer 2

A full code sample for this:
-(void)starTrack:(NSString *)uri {
NSURL *trackURL = [NSURL URLWithString:uri];
[[SPSession sharedSession] trackForURL:trackURL callback:^(SPTrack *track) {
if (track != nil) {
[SPAsyncLoading waitUntilLoaded:track timeout:kSPAsyncLoadingDefaultTimeout then:^(NSArray *tracks, NSArray *notLoadedTracks) {
[track setStarred:YES];
}];
}
}];
}