NSNotification Strangeness when used in conjunction with AsyncSocket

Question

I'm using AsyncSocket to connect to a server from my iPhone App. In the delegate that received data from the server, I post a notification that would tell the tableView's delegate to trigger a reloadData on the tableView:

- (void)onSocket:(AsyncSocket *)sock didReadData:(NSData*)data withTag:(long)tag {
    [[NSNotificationCenter defaultCenter] postNotificationName:@"PEERSTATUSCHANGED" object:self];
    [sock readDataToData:[AsyncSocket CRLFData] withTimeout:-1 tag:0];
}

and on the viewController:

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(peerStatusDidChange:) name:@"PEERSTATUSCHANGED" object:nil];
    }
    return self;
}


- (void)peerStatusDidChange:(NSNotification *)notification {
    NSLog(@"NOTIFICATION RECEIVED");
}

Now, this doesn't work at all. The notification is posed but not recognized by the ViewController. However, when I do the same thing in applicationDidFinishLaunching:

- (void)applicationDidFinishLaunching:(UIApplication *)application {    

protocol = [[XBBProtocol alloc] init];

SourceListViewController *sourceListVC = [[[SourceListViewController alloc] initWithNibName:@"SourceListViewController" bundle:nil] autorelease];
UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:sourceListVC] autorelease];

[[NSNotificationCenter defaultCenter] postNotificationName:@"PEERSTATUSCHANGED" object:self];
[protocol connectToServer];

// Override point for customization after application launch
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
}

I got the notification received in viewController.

Anyone knows why? does it have something to do with delegate methods of AsyncSocket being in different thread?

Thanks in advance.

Answer 1

One possibility is that your initWithNibName:bundle: method is not actually being called. If you instantiate the view controller in a NIB (rather than in code), then it calls initWithCoder: instead.

A quick way to check is to put a breakpoint in initWithNibName:bundle:.

Answer 2

Try putting the method that sends the notification in a different method, and call it with "performSelectorOnMainThread". It's very likely your network code is getting called in a background thread and thus when the notification fires, it informs the table view on the same thread...

You can't make UI calls on anything but the main thread.