iOS Development

Storage

Bundle: built into the application
Application Sandbox: directory limited in access to your application
- Documents: backed up - FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
- Library
  - Caches: not backed up
  - Preferences: backed up
- tmp: not backed up, should clear out when done

Scene States

Unattached: does not execute code, does not have any memory reserved
Foreground Active: interface on screen, accepting events, code handling them
Foreground Inactive: interrupted by a system event, like a phone call, Siri or task switcher. Visible and executing code, but not receiving events
Background State: home screen or another app. Save data and release shared resources as quickly as possible
Suspended State: after a default of 10 seconds of being in background state. Can't see interface, can't execute code. Like a snapshot. Stays as long as there is system memory (may still show in the task switcher, but will be relaunched)

| State | Visible | Receives Events | Executes Code| |:- | Unattached | no | no | no | Foreground Active | yes | yes | yes | Foreground Inactive | mostly | no | yes | Background | no | no | yes | Suspended | no | no | no

Clearing Out Devices

To remove large folders in ~/Library/Developer/CoreSimulator/Devices

Run xcrun simctl list devices to list devices
Run xcrun simctl delete [uuid] to delete any device