Question

I have BaseView which implement UIViewController. Every view in project must implement this BaseView.

In BaseView, I have method:

-(void) checkLoginStatus
{
    defaults = [[NSUserDefaults alloc] init];

    if(![[defaults objectForKey:@"USERID"] length] > 0 )
    {
        Login *login=[[Login alloc] initWithNibName:@"Login" bundle:nil];
        [self.navigationController pushViewController:login animated:TRUE];
        [login release];
    }
    [defaults release];
}

The problem is my Login view also implement BaseView, checks for login, and again open LoginView i.e. stuck in to recursive calling.

Can I check in checkLoginStatus method if request is from LoginView then take no action else check login.
Ex:

- (void) checkLoginStatus
{
    **if(SubView is NOT Login){** 
        defaults = [[NSUserDefaults alloc] init];

        if(![[defaults objectForKey:@"USERID"] length] > 0 )
        {
            Login *login=[[Login alloc] initWithNibName:@"Login" bundle:nil];
            [self.navigationController pushViewController:login animated:TRUE];
            [login release];
        }
        [defaults release];
    }
}

Please help..

Answer 1

Use the following method:

if ([self isMemberOfClass:[Login class]])
{
    CFShow(@"Yep, it's the login controller");
}

isMemberOfClass tells you if the instance is an exact instance of that class. There’s also isKindOfClass:

if ([self isKindOfClass:[BaseView class]])
{
    CFShow(@"This will log for all classes that extend BaseView");
}

isKind tests that the class is a extension of a certain class.

So given your example:

-(void) checkLoginStatus
{
    defaults = [[NSUserDefaults alloc] init];

    if (![self isMemberOfClass:[Login class]])
    {
        if (![[defaults objectForKey:@"USERID"] length] > 0 )
        {
            Login *login=[[Login alloc] initWithNibName:@"Login" bundle:nil];
            [self.navigationController pushViewController:login animated:TRUE];
            [login release];
        }
    }
    [defaults release];
}