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Problem

Sending silent notifications for release app version shows next log: SpringBoard[48] <Warning>: High Priority Push: [Bundle ID] - BAR Disabled

Any idea? BAR Disabled?? Looks like when "BAR Disabled" log appears, the method (didReceiveRemoteNotification - fetchCompletionHandler) is not being called.

More info

  • BAR Disabled Log appears in production app in tested iphone 4s and iphone6
  • BAR Disabled Log is not appearing in tested iPhone5, and fetchCompletionHandler is called.
  • BAR Disabled Log is not appearing while debugging.
  • BAR Disabled Log appears with param "content-available":1
  • Tested with swift and objective-c
  • Tested with Distribution profile(testflight) & adhoc profile(itunes)
  • iOS version 9.3.1

Notification

{"aps":{"alert":"Test","sound":"default","content-available":1}, "data" : 345}

Result

Displays notification with text "Test" and plays default sound but fetchCompletionHandler is not being called, just a log: SpringBoard[48] <Warning>: High Priority Push: [Bundle ID] - BAR Disabled

David
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1 Answers1

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BAR Disabled means that Background App Refresh is not enabled so app is not able to perform fetchCompletionHandler.

From device go to Settings > General > Background App Refresh and turn on Background App Refresh. If you quit an app from the app switcher, it might not be able to run or check for new content before you open it again.

More Info about Background App Refresh (BAR):

This is a whole other thing that works outside of the 10 minutes grace period. An app with BAR enabled is allowed to wake up every now and then until it's quit from the app switcher or the phone resprings/reboots. There is no 10 minute restriction here, and it's important to understand that BAR is different from backgrounding. By "wakes up" I mean "opens a sleepy eye and downloads some stuff, then goes straight back to sleep". If you kill the app from the app switcher, its BAR privilege is gone as well.

BAR-enabled apps are usually scheduled to wake up at opportune moments to update themselves. These moments include:

  • when the device is actively in use
  • when the device is connected to wifi and/or a power source
  • when a push notification for the app is received
  • when location changes

From Apple themselves: iOS learns patterns based on your use of the device and tries to predict when an app should be BAR-updated in the background. It also learns when the device is typically inactive, such as during the night, to reduce update frequency when the device is not in use.

Thanks to the information shared by /u/Niruga, there is also what is called a "silent" push notification that apps can make use of to wake their app up for BAR-updates. Silent push notifications are not seen by the user.

For example, Dropbox makes use of BAR and location to keep its photo upload working past 10 minutes for as long as it takes to finish uploading. It won't be constantly uploading, since that's not what BAR does. So what's happening in Dropbox is that it uses location changes to make the app wake up and upload for 10 minutes before it goes to back to sleep, then waits for the next location change to make the app wake up again and continue where it left off, and repeat until all uploading is done, all without the user having to keep the app open in the foreground.

To decide whether or not to enable BAR, think about whether you trust the app developers not to abuse the function.

Hope it helps.

ref: https://www.reddit.com/r/jailbreak/comments/3eao32/discussion_write_up_ios_backgrounding_and/

David
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