How to use Realm SDK with iOS App Extensions?

[matthewmorek]

I am developing an app that has a second App Target, an iOS Share Extension, which allows users to add website links to a database (Mongo Atlas) and I use Realm Swift SDK for the main app.

Due to the containerisation of app targets, my main app and the bundled iOS Share Extension use a shared App Group container and can share Realm configuration this way successfully.

Questions

• How do I share local database file between main app and share extension via App Group?
• How do I extend the user session between iOS App and Share Extension in a secure way? What would be the best strategy?
  1. Share auth details/keys via iOS Keychain (App Group) and re-authenticate via SDK (would it be possible?), add data locally, sync via Realm SDK (device → cloud)
  2. Share auth details/keys/userId via iOS Keychain (App Group) and add data via Atlas REST API, sync via Realm SDK (cloud → device)
• Do I need to notify the main app/realm that changes have been made in order for them to be synced, or is Realm SDK going to do it automatically from the Share Extension?

Thanks in advance for help