How to change the iVar of another class - iphone

Question

This is the code. It is pretty straight forward. I made two classes one is returning the error and hydrate the iVar of another class (TheView) and show it to the User. however I cant figure it out why the View return Null at all time. Thanks is advance guys.
#interface AccountControllerModel : NSObject {
NSString *anError;
}
#property (nonatomic, retain) NSString *anError;
AccountControllerModel.m
#synthesize anError;
- (void)uploadFailed:(ASIHTTPRequest *)theRequest{
RegistrationViewController *regoVC = [[RegistrationViewController alloc] init];
[regoVC manageTheError:#"THIS IS AN ERROR"];
[regoVC release]; regoVC = nil;
}
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
#interface RegistrationViewController : UIViewController {
NSMutableString *test;
}
#property (nonatomic, assign) NSMutableString *test;
#synthesize test;
-(void)viewDidLoad {
test = [[NSMutableString alloc] init];
}
-(void)manageTheError:(NSString *)theError{
self.test = [NSMutableString stringWithFormat:#"%#",theError];
resultOfRegistration.text = [NSString stringWithFormat:#"%#",self.test];
NSLog(#"test is %#",self.resultOfRegistration.text); //It comes back Null
}

Answer 1

Alex is right, some clarification on what's not working would help but by looking through I may have found your error. [[NSNotificationCenter defaultCenter] postNotificationName:#"Blah" object:self], you have object set to nil which could be your issue with the notification.

Answer 2

There are a number of problems with your code.
#property (nonatomic, assign) NSMutableString *test;
Two things here, one, exposing a NSMutable* object in a property is never a good idea, two you should 'copy' value objects, especially because this is how you're treating it in your code. Make this #property (nonatomic, copy) NSString *test;
regoVC.test = [NSMutableString stringWithString:self.anError];
You're assigning an autoreleased object to an assign property, this is a leak, the change above will fix that.
NSLog(#"test is %#",test); // It is perfect as you expect
test isn't in scope here, but I'd assume that was supposed to be regoVC.test, these other changes should remedy the situation.