ha-ios-persistence

name	ha-ios-persistence
description	Data persistence across GRDB, Realm, and UserDefaults. Use when adding or migrating a persistent model, choosing a storage layer, implementing DatabaseTableProtocol, or reading/writing config for Watch, CarPlay, widgets, or the entity registry.

Data Persistence

The project uses two database layers:

• GRDB (GRDB.swift): newer layer, accessed via Current.database(). Used for Watch config, CarPlay config, widget config, entity registry, panels, etc. When adding a new persistent model, prefer GRDB: implement DatabaseTableProtocol (defines tableName, definedColumns, and createIfNeeded) and register it in DatabaseQueue.tables() in GRDB+Initialization.swift. The protocol's migrateColumns helper auto-handles additive migrations.
• Realm (RealmSwift): legacy layer, used for older models (actions, zones, sensors, etc.). Access via Current.realm().
• UserDefaults: simple preferences and watch communication.