Question

I actually work on an iPad application, which contains a secured member area.
The application itself uses a TabBarNavigation with a UIViewController for each tab.

To show up the LoginForm on the “Member-Area”-Tab, when User is not logged in, I created the LoginScreen in a separate UIViewController and tried to present it as ModalView on the ViewWillAppear-Method.

Unlikely it seems that ViewWillAppear / ViewDidLoad can’t handle the modal view.
Every Tutorial or Sample I found uses a Button-Action to show up the ModalView.

Isn’t it possible to show it without pressing something?

The Code I used in “MemberViewController” ViewWillAppear looks like that:

        -(void)viewWillAppear:(BOOL)animated{
    LoginViewController *loginInstance = [[[LoginViewController alloc] init] autorelease];

    [self presentModalViewController:loginInstance animated:YES];    
    [loginInstance release];
}

Would be great if someone could help!

Answer 1

Create an empty UIViewController, with something like this:

#import "LoginViewController.h"
#import "MemberViewController.h"

- (void)viewDidLoad {
[super viewDidLoad];

[self performSelector:@selector(checkForLogin)];
}

- (void)checkForLogin {
NSString * checkString = [[NSUserDefaults standardUserDefaults] objectForKey:@"LoginCheck"];

if ([checkString isEqualToString:@"YES"]) {

MemberViewController * memberInstance = [[MemberViewController alloc] init];
[self presentModalViewController:memberInstance animated:YES];
[memberInstance release];

} else {

LoginViewController * loginInstance = [[LoginViewController alloc] init];
[self presentModalViewController:loginInstance animated:YES];
[loginInstance release];

}

}

In the LoginViewController.h add this to the function that’s being called when the login is valid:

[[NSUserDefaults standardUserDefaults] setObject:@"YES" forKey:@"LoginCheck"];
[[NSUserDefaults standardUserDefaults] synchronize];

I think this should do the trick 😉

There can be some errors, I typed this from my head right here on the website

Edit: attach the new empty view controller to the UITabBarController item where the login is needed 😉