A quick overview of session 204 of the WWDC 2013 videos (What's New with Multitasking)

1. What's New with Multitasking?
Jim Borden

2. Changes from iOS 6.x

3. Changes from iOS 6.x
●
New app switcher
behavior
–
Swipe up to remove
apps
–
Killing an app also
prevents background
activity
–
App snapshots are
live!

4. Changes from iOS 6.x
●
Background Mode Settings
–
User chooses how the app
can run in the background

5. New APIs in iOS 7.0
Background Fetch
●Remote Notifications
●Background Transfer Service
●

6. Background Fetch
●
UIBackgroundModes → fetch
●
[app setMinimumBackgroundFetchInterval:]

7. Remote Notifications

8. Remote Notifications
●
Receive message in background
–
Don't need to inform user at all
●
Content ready before user sees notification
●
Rate limited
–
Too many at a time = server queue
–
Device decides when is best to receive

9. Remote Notifications
●
UIBackgroundModes → remote-notification
●
content-available: 1 in APS payload

10. Background Transfer Service

11. Background Transfer Service
●
Managed by iOS
–
●
Survive application kills and system restarts
Discretionary transfer type
–
Power-managed and limited to wi-fi
–
All background initiated transfers
–
Foreground initiated transfers optional

12. Things to Note
●
Time-limited (< 1 minute vs 10 minutes)
●
Processed in parallel with other apps
–
●
Complete as soon as possible
–
●
CPU usage profiling very important
Device has to stay awake for your app
Snapshot is taken after this process
–
Hide sensitive information

13. Things to Note
●
Minimize hardware usage for battery's sake
–
Avoid CoreMotion, CoreLocation, etc
–
Bring radios down as quickly as possible
●
Parallelize transfers

14. Fin