Presenting a modal view controller using blocks

gistfile1.m

- (void)insertNewObject {
	__block NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext];
    
	NSEntityDescription *entity = [[self.fetchedResultsController fetchRequest] entity];
    Book *newBook = [NSEntityDescription insertNewObjectForEntityForName:[entity name] inManagedObjectContext:context];
	
	BookViewController *bookViewController = [[BookViewController alloc] init];
	bookViewController.book = newBook;
	
	__block __typeof__(self) blockSelf = self;
	
	[bookViewController setCancelBlock:^(BookViewController *controller) {
		[context rollback];
		[blockSelf dismissModalViewControllerAnimated:YES];
	}];
	
	[bookViewController setSaveBlock:^(BookViewController *controller) {
		NSError *error = nil;
		if (![context save:&error]) {
			NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
			abort();
		}
		[blockSelf.tableView reloadData];
		[blockSelf dismissModalViewControllerAnimated:YES];
	}];
	
	[self presentModalViewController:bookViewController animated:YES];
	[bookViewController release];
}