Best way to check if an iPhone app is running for the first time

Question

I want to check if my iPhone app is running for the first time. I can create a file in the documents folder and check that file to see if this is the first time the app is r

Answer 1

Use NSUserDefaults. If the sharedDefault has a key for your app, its run before. Of course, you'll have to have the app create at least one default entry the first time the app runs.

Answer 2

I like to use NSUserDefaults to store an indication of the the first run.

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];  
if (![defaults objectForKey:@"firstRun"])
  [defaults setObject:[NSDate date] forKey:@"firstRun"];

[[NSUserDefaults standardUserDefaults] synchronize];

You can then test for it later...

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];        
if([defaults objectForKey:@"firstRun"])           
{
  // do something or not...
}

Answer 3

Swift:

var isFirstLaunch: Bool {
    get {
        if (NSUserDefaults.standardUserDefaults().objectForKey("firstLaunchDate") == nil) {
            NSUserDefaults.standardUserDefaults().setObject(NSDate(), forKey: "firstLaunchDate")
            NSUserDefaults.standardUserDefaults().synchronize()
            return true
        }
        return false
    }
}

Another tip:

When using NSUserDefaults, these settings will be wiped if the app is ever deleted. If for some reason you require these settings to still hang around, you can store them in the Keychain.

Answer 4

In your app delegate register a default value:

NSDictionary *defaultsDict = 
[[NSDictionary alloc] initWithObjectsAndKeys:[NSNumber numberWithBool:YES], @"FirstLaunch", nil];
[[NSUserDefaults standardUserDefaults] registerDefaults:defaultsDict];
[defaultsDict release];

Then where you want to check it:

NSUserDefaults *sharedDefaults = [NSUserDefaults standardUserDefaults];
if ([sharedDefaults boolForKey:@"FirstLaunch"]) {
  //Do the stuff you want to do on first launch
  [sharedDefaults setBool:NO forKey:@"FirstLaunch"];
  [sharedDefaults synchronize];
}

Answer 5

You can implement it with the static method below. I think it's better since you can call this method as many times as you like, unlike the other solutions. enjoy: (Keep in mind that it's not thread-safe)

+ (BOOL)isFirstTime{
    static BOOL flag=NO;
    static BOOL result;
    if(!flag){
        if ([[NSUserDefaults standardUserDefaults] boolForKey:@"hasLaunchedOnce"])
        {
            result=NO;
        } else
        {
            [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"hasLaunchedOnce"];
            [[NSUserDefaults standardUserDefaults] synchronize];
            result=YES;
        }

    flag=YES;
    }
    return result;
}

Answer 6

You can use a custom category method isFirstLaunch with UIViewController+FirstLaunch.

- (BOOL)isFirstLaunch
{
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"kFirstLaunch"]) {
        return YES;
    }
    else {
        [[NSUserDefaults standardUserDefaults] setBool:YES forKey:@"kFirstLaunch"];
        [[NSUserDefaults standardUserDefaults] synchronize];
        return NO;
    }
}

And when you need to use it in controller

BOOL launched = [self isFirstLaunch];

if (launched) {
//if launched
}
else {
//if not launched
}