Conditions when didFinishLaunchingWithOptions get called by the IOS

Question

Can anybody tell me in what all scenarios does the delegate function didFinishLaunchingWithOptions gets called by the IOS apart from when app is launched for the first time. I launched the app into the device with XCode and removed the connectivity and then tried sending messages to the device through wifi. I then noticed that didFinishLaunchingWithOptions got called few number of times. Why is this happening and what are the conditions when this function gets called. I am not able to figure out all the scenarios. Thanks in advance.

Answer 1

Your question, can anybody tell me in what all scenarios does the delegate function didFinishLaunchingWithOptions gets called by the IOS ?

If app is killed or in terminated state and user receives a local notification or remote push notification, and user taps notification, then didFinishLaunchingWithOptions gets called first in both cases.

didFinishLaunchingWithOptions also gets called when you are monitoring location changes using "startMonitoringSignificantLocationChanges". From Apple

If you start this service and your app is subsequently terminated, the system automatically relaunches the app into the background if a new event arrives. In such a case, the options dictionary passed to the application(:willFinishLaunchingWithOptions:) and application(:didFinishLaunchingWithOptions:) methods of your app delegate contains the key location to indicate that your app was launched because of a location event.

Answer 2

From Apple documentation:

You should use this method (and the corresponding application:willFinishLaunchingWithOptions: method) to complete your app’s initialization and make any final tweaks. This method is called after state restoration has occurred but before your app’s window and other UI have been presented. At some point after this method returns, the system calls another of your app delegate’s methods to move the app to the active (foreground) state or the background state.