session timing example

HelloMixpanel/HelloMixpanel/AppDelegate.h

@@ -29,4 +29,6 @@
 
 @property (strong, nonatomic) Mixpanel *mixpanel;
 
+@property (strong, nonatomic, retain) NSDate *startTime;
+
 @end

HelloMixpanel/HelloMixpanel/AppDelegate.m

@@ -29,6 +29,7 @@ @implementation AppDelegate
 
 - (void)dealloc
 {
+    [_startTime release];
     [_window release];
     [_viewController release];
     [super dealloc];
@@ -43,8 +44,8 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
     // Initialize the MixpanelAPI object
     self.mixpanel = [Mixpanel sharedInstanceWithToken:MIXPANEL_TOKEN];
 
-    // Set the upload interval to 5 seconds for demonstration purposes. This would be overkill for most applications.
-    self.mixpanel.flushInterval = 5; // defaults to 60 seconds
+    // Set the upload interval to 10 seconds for demonstration purposes. This would be overkill for most applications.
+    self.mixpanel.flushInterval = 10; // defaults to 60 seconds
 
     // Name a user in Mixpanel Streams
     self.mixpanel.nameTag = @"Walter Sobchak";
@@ -61,6 +62,8 @@ - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(
     return YES;
 }
 
+#pragma mark * Push notifications
+
 - (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)devToken {
     [self.mixpanel.people addPushDeviceToken:devToken];
 }
@@ -82,4 +85,17 @@ - (void)application:(UIApplication *)application didReceiveRemoteNotification:(N
     [alert release];
 }
 
+#pragma mark * Session timing example
+
+- (void)applicationDidBecomeActive:(UIApplication *)application
+{
+    self.startTime = [NSDate date];
+}
+
+- (void)applicationWillResignActive:(UIApplication *)application
+{
+    NSNumber *seconds = [NSNumber numberWithDouble:[[NSDate date] timeIntervalSinceDate:self.startTime]];
+    [[Mixpanel sharedInstance] track:@"Session" properties:[NSDictionary dictionaryWithObject:seconds forKey:@"Length"]];
+}
+
 @end