Example for Login Screen Modally Based on Storyboard

Example for login screen modally based on storyboard

Here is scenario . Its so simple . I just hope that it will be useful.

For the UITableBarController give a name for identity to storyboard id

Then in your ViewController class file You have the authentication credentials right >.? Do some stuff over there for authentication . then follow this code . It works fine

- (IBAction)Login:(id)sender {

    if(authenticated)  // authenticated---> BOOL Value assign True only if Login Success
        {
            UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
            UITabBarController *obj=[storyboard instantiateViewControllerWithIdentifier:@"tab"];
            self.navigationController.navigationBarHidden=YES;
            [self.navigationController pushViewController:obj animated:YES];
        } 

iOS Modal Login Screen presented anywhere in app

OK so here is what I ended up doing:

As pointed out by John Woods, don't subclass UINavigationController. Instead, I created a base UIViewController, which in its viewWillAppear checks whether the user is logged in; if not, modally present the Login screen. All View Controllers that need to check the logged-in state inherit from this base View Controller, so it becomes the "central point" for checking the logged-in state (I don't like using the AppDelegate for this kind of logic).

I like Mike Pollard's suggestion of using notifications to notify when the user's token expires (since this may happen well before viewWillAppear is called). Subscribing to this notification can then also be done in the base View Controller.

Hendrik Demmer's solution is probably the most straightforward, but I don't like having a Login screen "lurking" around at the bottom of the view controller stack - or is this just nitpicking?

Best practices for Storyboard login screen, handling clearing of data upon logout

Here is what I ended up doing to accomplish everything. The only thing you need to consider in addition to this is (a) the login process and (b) where you are storing your app data (in this case, I used a singleton).

As you can see, the root view controller is my Main Tab Controller. I did this because after the user has logged in, I want the app to launch directly to the first tab. (This avoids any "flicker" where the login view shows temporarily.)

AppDelegate.m

In this file, I check whether the user is already logged in. If not, I push the login view controller. I also handle the logout process, where I clear data and show the login view.

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{

    // Show login view if not logged in already
    if(![AppData isLoggedIn]) {
        [self showLoginScreen:NO];
    }

    return YES;
}

-(void) showLoginScreen:(BOOL)animated
{

    // Get login screen from storyboard and present it
    UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
    LoginViewController *viewController = (LoginViewController *)[storyboard instantiateViewControllerWithIdentifier:@"loginScreen"];
    [self.window makeKeyAndVisible];
    [self.window.rootViewController presentViewController:viewController
                                             animated:animated
                                           completion:nil];
}

-(void) logout
{
    // Remove data from singleton (where all my app data is stored)
    [AppData clearData];

   // Reset view controller (this will quickly clear all the views)
   UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
   MainTabControllerViewController *viewController = (MainTabControllerViewController *)[storyboard instantiateViewControllerWithIdentifier:@"mainView"];
   [self.window setRootViewController:viewController];

   // Show login screen
   [self showLoginScreen:NO];

}

LoginViewController.m

Here, if the login is successful, I simply dismiss the view and send a notification.

-(void) loginWasSuccessful
{

     // Send notification
     [[NSNotificationCenter defaultCenter] postNotificationName:@"loginSuccessful" object:self];

     // Dismiss login screen
     [self dismissViewControllerAnimated:YES completion:nil];

}

Launching a login view before the tab bar controller is displayed

Finally figured this one out.. here is what you need to do:

1. Add a standalone login view to the storyboard.

2. Select the login view and in the attributes inspector, check the 'Is Initial View Controller'. This will switch the initial view being launched from the tab controller to the login view, thereby solving the whole issue of displaying the login screen first.

3. Add a button to the login view and create a segue to load the tab controller on push of the button. (Or you can create a segue from the login view to the tab controller view and programmatically invoke the segue as necessary).

4. Select the login view and choose option Editor > Embed In > Navigation Controller

5. In the attributes inspector for the Navigation controller, uncheck the 'Shows Navigation Bar' option (this is a cosmetic change; I am assuming you don't need a navigation bar showing on the login screen !!)

That's it :)

Presenting a login with storyboards for iOS

http://maybelost.com/2011/12/tutorial-storyboard-app-with-core-data/

Download this sample app. It contains a Login with CoreData. Its very simple :)

Several weeks ago i used that also for my first Login and it worked like charm.

Hope it will help you too!

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