Invoke model method with block that will run on the main thread

Question

one of the central tenets of the architecture of my latest app is that I\'m going to call methods on the app\'s model which will be async and accept failure and success scen

Answer 1

Similar approach works also with NSOperationQueue:

NSBlockOperation *aOperation = [NSBlockOperation blockOperationWithBlock:^ 
 {  
    if ( status == FAILURE )
    { 
        // Show alert -> make sure it runs on the main thread
        [[NSOperationQueue mainQueue] addOperationWithBlock:^ 
         {
             UIAlertView    *alert = [[[UIAlertView alloc] initWithTitle:@"Alert" message:@"Your action failed!" delegate:nil 
                                      cancelButtonTitle:@"Ok" otherButtonTitles:nil] autorelease];
             [alert show];
         }];
    }
 }];

// myAsyncOperationQueue is created somewhere else
[myAsyncOperationQueue addOperation:aOperation];