Will iOS launch my app into the background if it was force-quit by the user

Question

I am triggering a background fetch by using the content-available flag on a push notification  I have the fetch and remote-notification UIBackgroundModes enabled   Here is the implementation I am using in my AppDelegate m   -  void application  UIApplication   application didReceiveRemoteNotification  NSDictionary   userInfo fetchCompletionHandler  void     UIBackgroundFetchResult  completionHandler       NSLog   Remote Notification Recieved        UILocalNotification  notification     UILocalNotification alloc  init       notification alertBody      Looks like i got a notification - fetch thingy        application presentLocalNotificationNow notification       completionHandler UIBackgroundFetchResultNewData        When the app is running in the background  it works fine   The notification is received and the app triggered the  looks like i got a notification  local notification  as the code above should do     However  when the app is not running and a push notification is received with the content-available flag  the app is not launched and the didRecieveRemoteNotification delegate method is never called    The WWDC Video Whats New With Multitasking   204 from WWDC 2013  shows this    It says that the application is  launched into background  when a push notification is received with the content-available flag   Why is my app not launching into the background   So the real question is   Will iOS perform background tasks after the user has force-quit the app

User · Answer

Actually if you need to test background fetch you need to enable one option in scheme:

enabling bg fetch

Another way how you can test it: simulate bg fetch

Here is full information about this new feature: http://www.objc.io/issue-5/multitasking.html

User · Answer

I ve been trying different variants of this for days  and I thought for a day I had it re-launching the app in the background  even when the user swiped to kill  but no I can t replicate that behavior   It s unfortunate that the behavior is quite different than before   On iOS 6  if you killed the app from the jiggling icons  it would still get re-awoken on SLC triggers  Now  if you kill by swiping  that doesn t happen   It s a different behavior  and the user  who would continue to get useful information from our app if they had killed it on iOS 6  now will not   We need to nudge our users to re-open the app now if they have swiped to kill it and are still expecting some of the notification behavior that we used to give them   I m worried this won t be obvious to users when they swipe an app away   They may  after all  be basically cleaning up or wanting to rearrange the apps that are shown minimized

User · Answer

This might help you     In most cases  the system does not relaunch apps after they are force   quit by the user  One exception is location apps  which in iOS 8 and   later are relaunched after being force quit by the user  In other   cases  though  the user must launch the app explicitly or reboot the   device before the app can be launched automatically into the   background by the system  When password protection is enabled on the   device  the system does not launch an app in the background before the   user first unlocks the device    Source  https   developer apple com library content documentation iPhone Conceptual iPhoneOSProgrammingGuide BackgroundExecution BackgroundExecution html

User · Answer

You can change your target s launch settings in  Manage Scheme  to Wait for  lt app gt  app to be launched manually  which allows you debug by setting a breakpoint in application  didReceiveRemoteNotification  fetchCompletionHandler  and sending the push notification to trigger the background launch   I m not sure it ll solve the issue  but it may assist you with debugging for now

User · Answer

UPDATE2    You can achieve this using the new PushKit framework  introduced in iOS 8  Though PushKit is used for VoIP  So your usage should be for VoIP related otherwise there is risk of app rejection   See this answer      UDPDATE1   The documentation has been clarified for iOS8  The documentation can be read here  Here is a relevant excerpt      Use this method to process incoming remote notifications for your app    Unlike the application didReceiveRemoteNotification  method  which is   called only when your app is running in the foreground  the system   calls this method when your app is running in the foreground or   background  In addition  if you enabled the remote notifications   background mode  the system launches your app  or wakes it from the   suspended state  and puts it in the background state when a push   notification arrives  However  the system does not automatically   launch your app if the user has force-quit it  In that situation  the   user must relaunch your app or restart the device before the system   attempts to launch your app automatically again      Although this was not made clear by the WWDC video  a quick search on the developer forums turned this up   https   devforums apple com message 873265 873265  login required      Also keep in mind that if you kill your app from the app switcher    i e  swiping up to kill the app  then the OS will never relaunch the   app regardless of push notification or background fetch   In this case   the user has to manually relaunch the app once and then from that   point forward the background activities will be invoked  -pmarcos   That post was by an Apple employee so I think i can trust that this information is correct   So it looks like when the app is killed from the app switcher  by swiping up   the app will never be launched  even for scheduled background fetches

User · Answer

The answer is YES  but shouldn t use  Background Fetch  or  Remote notification   PushKit is the answer you desire    In summary  PushKit  the new framework in ios 8  is the new push notification mechanism which can silently launch your app into the background with no visual alert prompt even your app was killed by swiping out from app switcher  amazingly you even cannot see it from app switcher   PushKit reference from Apple      The PushKit framework provides the classes for your iOS apps to   receive pushes from remote servers  Pushes can be of one of two types    standard and VoIP  Standard pushes can deliver notifications just as   in previous versions of iOS  VoIP pushes provide additional   functionality on top of the standard push that is needed to VoIP apps   to perform on-demand processing of the push before displaying a   notification to the user    To deploy this new feature  please refer to this tutorial  https   zeropush com guide guide-to-pushkit-and-voip - I ve tested it on my device and it works as expected

User · Answer

For iOS13 For background pushes in iOS13  you must set below parameters  apns-priority   5 apns-push-type   background   Required for WatchOS   Highly recommended for Other platforms    The video link  https   developer apple com videos play wwdc2019 707

[ios] Will iOS launch my app into the background if it was force-quit by the user?

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