在用户首次打开应用程序时处理登录屏幕的最佳方法是什么？

Question

I'm building an iOS app at the moment and trying to work out the best way to present the necessary screens.

The app is a tab-based app but the tabbar and it's children should not be visible until after the user has signed in.

Currently, the app delegate sets the tabbarcontroller as the root view controller when application:didFinishLaunchingWithOptions is called and then the first controller in the tab bar controller presents the sign in view controller if required.

The problem I have with this approach is that the first view controller in the tab bar is very busy. It makes a few requests to external APIs, some of which require a valid session token first.

What I'd like to do, unless someone can suggest a better solution, is to check in application:didFinishLaunchingWithOptions whether there's a valid session ID or not. If there is, set the tabBarController as the rootViewController, if there's not, set the sign in controller as the root view controller.

can anyone see any pitfalls in this idea?

Answer 1

Use NSUserDefault for storing bool value which will be true first time and login screen will appear along with make bool value to false. So second login scrren will not appear

Add this in application:didFinishLaunchingWithOptions method:

 [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"FirstTime"];
 [[NSUserDefaults standardUserDefaults] synchronize];

Now

 if([[NSUserDefaults standardUserDefaults] boolForKey:@"FirstTime"] == YES)
 {
    [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"FirstTime"];
    [[NSUserDefaults standardUserDefaults] synchronize];
   //login screen
 } 

Answer 2

I've used both approaches in my apps and the first one you've described is the best one since you won't need to mess up with changing your view controllers hierarchy. You really should have a boolean value stored in NSUserDefaults and another boolean value in your first view controller. Check the userDefault bool value in your tabbar's first view controller's viewDidLoad method to see if user is authenticated, if he's not, set the first view controller's bool value to appropriate value and do not perform the actions that you are required to perform via third party APIs, authenticate, set the bool to appropriate value and go back to the third party APIs.