App State Restoration - Swift Bangalore #9

Transcript

1. App State Restoration G. Abhisek iOS Engineer at OLA
2. What are we gonna discuss? • What is State Restoration? • How does it help us? • How does it work internally? • How to integrate?
3. What is App State Restoration? • Restore Behaviour and Appearance • Restore applications Semantic State
4. What are we looking at?
5. How does it help us? Only the strongest will survive
6. Let us INTEGRATE …. !! • App Delegate • View Controllers • Save Data & Restore Data
7. App Delegate • Enable State Restoration
8. View Controllers • Provide with Restoration Identifier • Confirm to UIStateRestoring Protocol • Provide a Restoration Class (Optional) • Confirm to UIViewControllerRestoration Protocol (Optional) • Encode and Decode relevant Data
9. • If RestorationIdentifier is not set, UIKit skips restoration for the view controller & subsequent controllers in hierarchy • Storyboard handles providing restoration class and reference to controller for restoration • If implemented without storyboard, provide restoration id, restoration class and controllers instance.
10. UIStateRestoring Protocol
11. UIViewControllerRestoration Protocol
12. What to save? What not to save? • Data necessary to recreate the view controller • Primary key of records • UI states e.g. Slider value, Button Selection • Its not user defaults nor data • Saved state can be lost • If data is a preference, don’t store it in state restoration archive • Don’t convert to data and encode
13. Control Flow App Launches Load initial UI First App initialisation Does your app supports state restoration ? Get the ViewControllers Decode saved objects Finish App restoration Finish App Initialisation Run App NO YES UIKit appDelegate: applicationWillFinishLaunching: appDelegate: shouldRestoreApplicationState: viewController: withRestorationIdentifierPath viewController: decodeRestorableState appDelegate: didDecodeRestorableState
14. Testing State Restoration • RestorationArchiveTool • StateRestorationDebugLogging.mobileconfig • StateRestorationDeveloperMode.mobileconfig
15. What we discussed? • What is State Restoration? • What are its benefits? • How to integrate within App? • Do’s and Don’ts • Control Flow
16. Thanks