Question

I added this code which functions as an auto timeout in my app. The userDefaults doubleForKey:@"timeoutLength" should be in minutes. For example, if value is 500, that should mean 500 minutes.

I keep seeming to be hitting the timout loop though even when it hasn’t really been 500 + min. Is anything wrong in my code? Perhaps a minutes/seconds error etc.

    [userDefaults setDouble:[[userContextDictionary valueForKey:@"autologout_idle_timeout"] doubleValue] forKey:@"timeoutLength"];


    double timeDifference = ([[NSDate date] timeIntervalSince1970] - [userDefaults doubleForKey:@"Close Time"]) / 60;

    if (timeDifference > [userDefaults doubleForKey:@"timeoutLength"]) {
        NSLog(@"Timeout Hit");
    } else {
        NSLog(@"No Timeout");
    }

Edit:

- (void)applicationDidEnterBackground:(UIApplication *)application {
    [userDefaults setObject:[NSDate date]  forKey:@"Close Time"];
}

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {   
    [userDefaults setDouble:[[userContextDictionary valueForKey:@"autologout_idle_timeout"] doubleValue] forKey:@"timeoutLength"];  
    //This is an int like 500, or 600, etc. 

    NSDate *closeDate = [userDefaults objectForKey:@"Close Time"]
    NSTimeInterval timeWhenClosedTimeInterval = [closeDate timeIntervalSince1970];
    NSTimeInterval todayTimeInterval = [[NSDate date] timeIntervalSince1970];

    NSTimeInterval timeDifference = ((todayTimeInterval - timeWhenClosedTimeInterval ) / 60);
    if (timeDifference > [userDefaults doubleForKey:@"timeoutLength"]) {
        NSLog(@"Timeout Hit");
    } else {
        NSLog(@"No Timeout");
    }
    return YES;
}

Answer 1

NSTimeInterval is expressed in seconds, not minutes.

Here’s the Apple doc where it’s described.

I’m not 100% certain what your ultimate problem with, but 500 seconds doesn’t seem like nearly enough time.

In the meantime, I wrote up some changes to your code to demo for myself:

NSDate * yesterday = [[NSDate date] dateByAddingTimeInterval: (-1 * 60 * 60 * 24 )];
NSTimeInterval yesterdayTimeInterval = [yesterday timeIntervalSince1970];
NSTimeInterval todayTimeInterval = [[NSDate date] timeIntervalSince1970];

// this properly converts timeDifference in seconds to minutes
NSTimeInterval timeDifference = ((todayTimeInterval - yesterdayTimeInterval ) / 60);
NSLog( @"time difference is %4.2f", timeDifference );

which came up with 1400 minutes (divided by 60 minutes per hour = 24 hours).