How can I show a view on the first launch only?

Question

I built an application using Xcode 4.5 with storyboards. The first time the app launches I want the initial view controller to appear with terms and conditions that must be accepted to proceed. After that, I want the app to launch and skip over the first view controller and go to the second one.

I know I have to use the NSUserDefaults class and something to the effect of: if ([[NSUserDefaults standard...] boolForKey:@"iHaveAcceptedTheTerms"])

But I have never used this class before and have no idea how to implement this code. Can someone share the specifics of how to do this?

score 14 · Answer 1 · answered Jul 13 '15 at 15:02

14

In the interests of keeping this question up-to-date, here is a Swift version of the accepted answer.

STEP 1

In your App Delegate, add the following function.

func applicationDidFinishLaunching(application: UIApplication) {
    if !NSUserDefaults.standardUserDefaults().boolForKey("TermsAccepted") {
        NSUserDefaults.standardUserDefaults().setBool(false, forKey: "TermsAccepted")
    }
}

This will essentially set your TermsAccepted Bool to false if this is the first launch (as Bools are false by default).

STEP 2

In your root view controller (the view controller which loads when your app is launched), you must have a way to see if the terms have been accepted or not and act accordingly.

Add the following function.

override func viewDidAppear(animated: Bool) {
    if NSUserDefaults.standardUserDefaults().boolForKey("TermsAccepted") {
        // Terms have been accepted, proceed as normal
    } else {
        // Terms have not been accepted. Show terms (perhaps using performSegueWithIdentifier)
    }
}

STEP 3

Once the user accepts your conditions, you want to change your TermsAccepted Bool to true. So in the body of the method which handles the acceptance of the terms, add the following line.

NSUserDefaults.standardUserDefaults().setBool(true, forKey: "TermsAccepted")

I hope this helps!

Loic

answered Jul 13 '15 at 15:02

Loic Verrall

985
15
25

It works perfectly for me. BTW Does it matter if I call the first method in the didFinishLaunchingWithOptions instead of applicationDidFinishLaunching? Upvoted +1 – CAN Aug 26 '15 at 07:31
I am getting `Signal SIGABRT` in my App Delegate. What's going on? – Javi Rando Feb 29 '16 at 14:41
Have you identified which line is causing that? – Loic Verrall Feb 29 '16 at 15:12
I am getting **Presenting view controllers on detached view controllers** error on performing a segue after this. How to skip a view controller ? – Tanmay Baranwal May 02 '16 at 13:17
@TanmayBaranwal are you presenting a view controller/performing a segue in `viewDidAppear`? That might explain that error. – Loic Verrall May 02 '16 at 17:31
@LoicVerrall I implemented it in `viewDidLoad`. Is there any way to do it ? – Tanmay Baranwal May 03 '16 at 11:08
@TanmayBaranwal Are you using a UINavigationController? If so, does this help you: http://stackoverflow.com/a/21003988/3100991 ? – Loic Verrall May 03 '16 at 16:52

score 10 · Accepted Answer · answered Oct 14 '12 at 00:15

10

You put in in your AppDelegate:

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

//first-time ever defaults check and set
if([[NSUserDefaults standardUserDefaults] boolForKey:@"TermsAccepted"]!=YES)
{
    [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"TermsAccepted"];
}

Then you implement in your rootViewController the terms and conditions and a way to accept it. You will have to check if the terms are accepted, for example like this:

if ([[NSUserDefaults standardUserDefaults] boolForKey:@"TermsAccepted"]){
    //proceed with app normally
}
else{
//show terms
}

When accepted, the following code will change the default settings:

 if(termsaccepted){
    [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"TermsAccepted"];
}

answered Oct 14 '12 at 00:15

NightCoder

1,049
14
22

Ok thanks. Can you elaborate on just how to get the app to "proceed normally" versus "show the terms"? – jac300 Oct 14 '12 at 01:02
This is up to you. For example, the very first time the user launches the app, the viewController ( or the view only, if you use a single VC) displaying the terms is shown. When the terms are accepted, you close it and go to the second one as you mentioned. This can be done by the root VC as explained by alexandresoli. Next time the user comes, the root VC will show the second VC immediately. – NightCoder Oct 14 '12 at 01:16
Thanks. Yes, I understand the concept, but I cannot figure out the code. So let's say the terms have been accepted... how do I construct code that tells the program to "skip the current terms view and go to the next one"? In other words, in looking at alexandresoli's code piece: [self presentViewController:YOUR_TERMS_CONTROLLER animated:YES completion:nil]; what is "YOUR_TERMS_CONTROLLER", how do I label a view controller and programatically refer to it? – jac300 Oct 14 '12 at 01:26
2

Maybe this goes beyond the scope of the question. Try [this one](http://stackoverflow.com/questions/8623524/show-view-from-storyboard-chain?rq=1)or [this one](http://stackoverflow.com/questions/6231676/how-do-i-launch-a-new-view-right-after-a-purchase-is-made-and-how-can-i-make-thi?rq=1) for example. – NightCoder Oct 14 '12 at 02:02

score 5 · Answer 3 · answered Nov 22 '16 at 23:17

Swift 3 Version

In AppDelegate.swift:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    if !UserDefaults.standard.bool(forKey: "Walkthrough") {
        UserDefaults.standard.set(false, forKey: "Walkthrough")
    }
}

In root view controller:

override func viewDidLoad() {
    super.viewDidLoad()
    if UserDefaults.standard.bool(forKey: "Walkthrough") {
        // Terms have been accepted, proceed as normal            
    } else {
        // Terms have not been accepted. Show terms (perhaps using 
    }
}

When terms have been accepted, or tutorial walkthrough is finished:

UserDefaults.standard.set(true, forKey: "Walkthrough")

score 4 · Answer 4 · answered Oct 14 '12 at 00:14

4

It will look like this on your first view or delegate:

NSUserDefaults * standardUserDefaults = [NSUserDefaults standardUserDefaults];

BOOL isAccepted = [standardUserDefaults boolForKey:@"iHaveAcceptedTheTerms"];

if (!isAccepted) {
    [self presentViewController:YOUR_TERMS_CONTROLLER animated:YES completion:nil];
} else {
    [self.navigationController pushViewController:YOUR_NORMAL_CONTROLLER animated:YES];
}

Dont forget to save the user response on your terms controller:

[standardUserDefaults setBool:YES forKey:@"iHaveAcceptedTheTerms"];

answered Oct 14 '12 at 00:14

alexandresoli

918
1
9
18

Ok, so I placed the first block of code in the viewDidLoad of the "terms" view controller, is that right? But then, how do I set the name of the view controller... in other words, how do I get it to recognize the name of "YOUR_TERMS_CONTROLLER"? – jac300 Oct 14 '12 at 00:30
YOUR_TERMS_CONTROLLER is the view controller that appear after the user accept the terms. The correct place to put the code is inside the view that calls your terms controller, it will be responsible to call the terms or not. If you have more doubts try to edit your question and put some code. – alexandresoli Oct 14 '12 at 00:34

How can I show a view on the first launch only?

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