Storage: CoreData: saving and loading works.

1Weather/Model/LocationManager.swift

@@ -21,6 +21,7 @@ public class LocationManager {
         
     private let weatherUpdateSource: WeatherSource
     private let healthSource: HealthSource
+    private let storage: Storage
     private var defaultLocation = Location(deviceLocation: false,
                                            coordinates: .init(latitude: 37.3230, longitude: -122.0322), // Cupertino
                                            timeZone: TimeZone(abbreviation: "PST")!) {
@@ -61,7 +62,7 @@ public class LocationManager {
                 guard let self = self else { return }
                 delegate.locationManager(self, updatedLocationsList: self.locations)
             }
-
+            storage.save(locations: locations, selectedIndex: selectedLocationIndex)
         }
     }
     
@@ -125,14 +126,29 @@ public class LocationManager {
         }
     }
     
-    public static let shared = LocationManager(weatherUpdateSource: WdtWeatherSource(), healthSource: BlendHealthSource())
+    public static let shared = LocationManager(weatherUpdateSource: WdtWeatherSource(), healthSource: BlendHealthSource(), storage: CoreDataStorage())
     public let maxLocationsCount = 12
     
-    public init(weatherUpdateSource: WeatherSource, healthSource: HealthSource) {
+    public init(weatherUpdateSource: WeatherSource, healthSource: HealthSource, storage: Storage) {
         self.weatherUpdateSource = weatherUpdateSource
         self.healthSource = healthSource
         self.deviceLocationMonitor = DeviceLocationMonitor()
+        self.storage = storage
         self.deviceLocationMonitor.delegate = self
+        
+        storage.load { [weak self] (locations, selectedIndex, error) in
+            guard let self = self else { return }
+            guard error == nil else {
+                self.log.error("Error while loading locations: \(error!)")
+                return
+            }
+            guard let locations = locations else {
+                assertionFailure("Either error or locations have to be nil, not both")
+                return
+            }
+            self.locations = locations
+            self.selectedLocationIndex = selectedIndex
+        }
     }
     
     public func updateAllWeatherIfNeeded() {

1Weather/Storage/CoreData/CoreDataStorage.swift

@@ -9,7 +9,7 @@ import Foundation
 import CoreData
 
 public class CoreDataStorage: Storage {
-    private let log = Logger(componentName: "CoreDataStorage")
+    private let log = Logger(componentName: "CoreDataStorage 💾")
     private lazy var managedContext: NSManagedObjectContext? = {
         persistentContainer.newBackgroundContext()
     }()
@@ -23,7 +23,8 @@ public class CoreDataStorage: Storage {
         return container
     }()
     
-    public func save(locations: [Location], selectedIndex: Int) {
+    public func save(locations: [Location], selectedIndex: Int?) {
+        log.info("Save: start")
         managedContext?.perform { [weak self] in
             guard let self = self else { return }
             guard let context = self.managedContext else {
@@ -36,20 +37,28 @@ public class CoreDataStorage: Storage {
                     context.insert(coreAppData)
                     try self.save(context: context)
                 }
+                self.log.info("Save: success")
             }
             catch {
-                self.log.error("Error during saving: \(error)")
+                self.log.error("Save: error: \(error)")
             }
         }
     }
     
     public func load(completion: @escaping StorageCompletion) {
+        log.info("Load: start")
         managedContext?.perform { [weak self] in
             guard let self = self else { return }
             guard let context = self.managedContext else {
                 return
             }
-            let completionOnMain: StorageCompletion = { (locations, selectedIndex, error) in
+            let completionOnMain: StorageCompletion = { [weak self] (locations, selectedIndex, error) in
+                if error != nil {
+                    self?.log.error("Load: error.")
+                }
+                else {
+                    self?.log.info("Load: success. \(String(describing: locations?.count)) locations, selected: \(String(describing: selectedIndex))")
+                }
                 DispatchQueue.main.async {
                     completion(locations, selectedIndex, error)
                 }
@@ -73,19 +82,29 @@ public class CoreDataStorage: Storage {
     }
     
     private func deleteAll(in context: NSManagedObjectContext) throws {
+        log.debug("Delete: start")
         let fetchRequest: NSFetchRequest<CoreAppData> = CoreAppData.fetchRequest()
         let appDataObjects = try context.fetch(fetchRequest)
         if appDataObjects.count > 1 {
             log.warning("Somehow we ended up with more than 1 CoreAppData objects in the DB... deleting them all.")
         }
+        if appDataObjects.count > 0 {
+            log.debug("Delete: \(appDataObjects.count) objects...")
+        }
         for appData in appDataObjects {
             context.delete(appData)
         }
+        log.info("Delete: success")
     }
     
     private func save(context: NSManagedObjectContext) throws {
+        log.info("Context save: start")
         if context.hasChanges {
             try context.save()
+            log.info("Context save: success")
+        }
+        else {
+            log.info("Context save: no need")
         }
     }
 }

1Weather/Storage/CoreData/CoreDataUtils.swift

@@ -68,7 +68,8 @@ struct CoreDataUtils {
         return result
     }
     
-    public static func appValue<T>(name: String, value: T.RawValue?, in entity: Any) throws -> T? where T: RawRepresentable {
+    // I tried calling it just appValue, so that Swift would figure out wether to use this one or non-optional one, but it gets stuck in infinite recursion in this method occasionally.
+    public static func appValueOptional<T>(name: String, value: T.RawValue?, in entity: Any) throws -> T? where T: RawRepresentable {
         guard let value = value else {
             return nil
         }

1Weather/Storage/CoreData/Objects/Human/CoreCurrentWeather.swift

@@ -14,7 +14,7 @@ open class CoreCurrentWeather: _CoreCurrentWeather, CoreDataAppModelConvertable
         result.minTemp = try CoreDataUtils.measurement(from: self.minTemp, in: self, attributeName: "minTemp")
         result.maxTemp = try CoreDataUtils.measurement(from: self.maxTemp, in: self, attributeName: "maxTemp")
         result.windSpeed = try CoreDataUtils.measurement(from: self.windSpeed, in: self, attributeName: "windSpeed")
-        result.windDirection = try CoreDataUtils.appValue(name: "windDirection", value: self.windDirection, in: self)
+        result.windDirection = try CoreDataUtils.appValueOptional(name: "windDirection", value: self.windDirection, in: self)
         if let precipProb = self.precipitationProbability {
             result.precipitationProbability = Percent(precipProb.uintValue)
         }
@@ -29,12 +29,12 @@ open class CoreCurrentWeather: _CoreCurrentWeather, CoreDataAppModelConvertable
         
         result.sunrise = self.sunrise
         result.sunset = self.sunset
-        result.sunState = try CoreDataUtils.appValue(name: "sunState", value: self.sunState, in: self)
+        result.sunState = try CoreDataUtils.appValueOptional(name: "sunState", value: self.sunState, in: self)
         result.moonrise = self.moonrise
         result.moonset = self.moonset
         result.approximateMoonrise = self.approximateMoonrise
-        result.moonState = try CoreDataUtils.appValue(name: "moonState", value: self.moonState, in: self)
-        result.moonPhase = try CoreDataUtils.appValue(name: "moonPhase", value: self.moonPhase, in: self)
+        result.moonState = try CoreDataUtils.appValueOptional(name: "moonState", value: self.moonState, in: self)
+        result.moonPhase = try CoreDataUtils.appValueOptional(name: "moonPhase", value: self.moonPhase, in: self)
         return result
     }
     

1Weather/Storage/CoreData/Objects/Human/CoreDailyWeather.swift

@@ -15,19 +15,19 @@ open class CoreDailyWeather: _CoreDailyWeather, CoreDataAppModelConvertable {
         result.minTemp = try CoreDataUtils.measurement(from: self.minTemp, in: self, attributeName: "minTemp")
         result.maxTemp = try CoreDataUtils.measurement(from: self.maxTemp, in: self, attributeName: "maxTemp")
         result.windSpeed = try CoreDataUtils.measurement(from: self.windSpeed, in: self, attributeName: "windSpeed")
-        result.windDirection = try CoreDataUtils.appValue(name: "windDirection", value: self.windDirection, in: self)
+        result.windDirection = try CoreDataUtils.appValueOptional(name: "windDirection", value: self.windDirection, in: self)
         if let precipProb = self.precipitationProbability {
             result.precipitationProbability = Percent(precipProb.uintValue)
         }
         
         result.sunrise = self.sunrise
         result.sunset = self.sunset
-        result.sunState = try CoreDataUtils.appValue(name: "sunState", value: self.sunState, in: self)
+        result.sunState = try CoreDataUtils.appValueOptional(name: "sunState", value: self.sunState, in: self)
         
         result.moonrise = self.moonrise
         result.moonset = self.moonset
-        result.moonState = try CoreDataUtils.appValue(name: "moonState", value: self.moonState, in: self)
-        result.moonPhase = try CoreDataUtils.appValue(name: "moonPhase", value: self.moonPhase, in: self)
+        result.moonState = try CoreDataUtils.appValueOptional(name: "moonState", value: self.moonState, in: self)
+        result.moonPhase = try CoreDataUtils.appValueOptional(name: "moonPhase", value: self.moonPhase, in: self)
         return result
     }
     

1Weather/Storage/CoreData/Objects/Human/CoreHourlyWeather.swift

@@ -15,7 +15,7 @@ open class CoreHourlyWeather: _CoreHourlyWeather, CoreDataAppModelConvertable {
         result.apparentTemp = try CoreDataUtils.measurement(from: self.apparentTemp, in: self, attributeName: "apparentTemp")
             
         result.windSpeed = try CoreDataUtils.measurement(from: self.windSpeed, in: self, attributeName: "windSpeed")
-        result.windDirection = try CoreDataUtils.appValue(name: "windDirection", value: self.windDirection, in: self)
+        result.windDirection = try CoreDataUtils.appValueOptional(name: "windDirection", value: self.windDirection, in: self)
         if let precipProb = self.precipitationProbability {
             result.precipitationProbability = Percent(precipProb.uintValue)
         }

1Weather/Storage/CoreData/Objects/Human/CoreLocation.swift

@@ -47,6 +47,7 @@ open class CoreLocation: _CoreLocation, CoreDataAppModelConvertable {
             return nil
         }
         self.init(managedObjectContext: context)
+        self.deviceLocation = appModel.deviceLocation
         
         self.lastWeatherUpdateDate = appModel.lastWeatherUpdateDate
         if let coordinates = appModel.coordinates {
@@ -61,7 +62,7 @@ open class CoreLocation: _CoreLocation, CoreDataAppModelConvertable {
         self.nickname = appModel.nickname
         self.zip = appModel.zip
         self.fipsCode = appModel.fipsCode
-        
+        self.timeZone = try CoreDataUtils.timeZoneToString(appModel.timeZone, in: self, attributeName: "timeZone")
         
         self.today = skipIfError(attribute: "today", action: {try CoreCurrentWeather(context: context, appModel: appModel.today)})
         

1Weather/Storage/Storage.swift

@@ -10,6 +10,6 @@ import Foundation
 public typealias StorageCompletion = ([Location]?, Int?, Error?) -> ()
 
 public protocol Storage {
-    func save(locations: [Location], selectedIndex: Int)
+    func save(locations: [Location], selectedIndex: Int?)
     func load(completion: @escaping StorageCompletion)
 }