Question

I have a custom UIViewController shown with presentModalViewController function in a http basic authentication delegate to get username and password. I want to wait till the user clicked the login button on the modal view controller shown on the screen. How can I do this? I am new to iOS any comments or links would be appreciated.

Edit : here is a sample code inside NSURLConnectionDelegate

-(void) connection(NSURLConnection*)connection willSendRequestForAuthenticationChallenge(NSURLAuthenticationChallenge*)challenge
{
    CustomAuthViewController *authView = [CustomAuthViewController alloc] initWithNibName"@"CustomAuthViewController" bundle:[NSBundle mainBundle]];
    [parentcontroller presentModalViewController:authView animated:YES];
    // 
    // I want to wait here somehow till the user enters the username/password
    //
    [[challenge sender] userCredentials:credentials forAuthenticationChallenge:challenge];
}

Kind regards.

Edit : Solution : It is not necessary to send the credentials in the willSendRequestForAuthenticationChallenge delegate function right away. I can send it anytime later, It is strange though.

Answer 1

Basically what you want is to pass a message from the modal UIViewController to the caller when your login dialog completes. There are a number of ways to do this. Here’s a couple:

Option 1 – Delegate Pattern:

On your modal dialog .h

@protocol LoginDelegate
- (void)loginComplete:(NSString *)userId;
- (void)loginFailed;
@end

@interface MyLoginDialog : UIViewController {
    UIViewController *delegate;
}

@property (nonatomic, retain) UIViewController *delegate;

On your modal dialog .m

in your init:

delegate = nil;

in your dealloc:

[delegate release];

when you complete your login:

[delegate dismissModalViewControllerAnimated:YES]; 
[delegate loginComplete:userId] or [delegate loginFailed];

Then on your calling view controller implement the LoginDelegate protocol.

And when you create your login view controller, set the delegate:

UIViewController *viewLogin = [[UIViewController alloc] init];
viewLogin.delegate = self;

Option 2 – Post a notification with NSNotificationCenter:

On your login dialog:

[self dismissModalViewControllerAnimated:YES];
[[NSNotificationCenter defaultCenter] postNotificationName:@"LoginComplete" object:nil];

On your calling view controller

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(loginComplete:) name:@"LoginComplete" object:nil];

Then you implement the selector loginComplete.

If you want to pass back login information (username, userId, etc) you can package that into a dictionary and add it as the “object” in the postNotificationName method.

You also need to be sure to call

[[NSNotificationCenter defaultCenter] removeObserver:self];  

when you are done listening.