Add CoreData utils

AppleLibs/Utils/CoreData/ContextHolder.swift

+//
+//  ContextHolder.swift
+//  WolfManagementMobile
+//
+//  Created by Tobias on 08.07.20.
+//  Copyright © 2020 Tobias. All rights reserved.
+//
+
+import Foundation
+import CoreData
+
+protocol ContextHolder
+{
+    var dataContainer: NSPersistentContainer { get }
+
+    // MARK: - Core Data Saving support
+
+    func saveContext()
+}

AppleLibs/Utils/CoreData/CoreData+Extended.swift

+//
+//  CoreDataExtension.swift
+//  DocumentRepositoryMobile
+//
+//  Created by Tobias on 19.01.19.
+//  Copyright © 2019 Tobias. All rights reserved.
+//
+
+import UIKit
+import CoreData
+import Resolver
+import Logging
+
+class AppContextHolder: ContextHolder
+{
+    private static let logger = Logger(label: "de.tobias.AppleLibs.coredata")
+
+    // MARK: - Core Data stack
+    lazy var dataContainer: NSPersistentContainer = {
+        let container = NSPersistentContainer(name: "DataModel")
+        container.loadPersistentStores(completionHandler: { (_, error) in
+            if let error = error as NSError? {
+                fatalError("Unresolved error \(error), \(error.userInfo)")
+            }
+        })
+        return container
+    }()
+
+    // MARK: - Core Data Saving support
+
+    func saveContext() {
+        saveContext(context: dataContainer.viewContext)
+    }
+
+    private func saveContext(context: NSManagedObjectContext) {
+        if context.hasChanges {
+            do {
+                try context.save()
+            } catch {
+                // Replace this implementation with code to handle the error appropriately.
+                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
+                let error = error as NSError
+                AppContextHolder.logger.error("Unresolved error \(error), \(error.userInfo)")
+            }
+        }
+    }
+}
+
+extension NSManagedObject
+{
+    private static let logger = Logger(label: "de.tobias.AppleLibs.coredata")
+
+    static var contextHolder: ContextHolder {
+        Resolver.resolve()
+    }
+
+    static var className: String {
+        NSStringFromClass(self).components(separatedBy: ".").last!
+    }
+
+    static var context: NSManagedObjectContext {
+        return contextHolder.dataContainer.viewContext
+    }
+
+    class func create() -> NSManagedObject? {
+        // logger.info("Create CoreData Object \(className)")
+        let context = NSManagedObject.context
+
+        let entity = NSEntityDescription.entity(forEntityName: className, in: context)
+        return NSManagedObject(entity: entity!, insertInto: context)
+    }
+
+    class func list<T: NSManagedObject>() -> [T] {
+        let request = NSFetchRequest<NSFetchRequestResult>(entityName: className)
+        request.returnsObjectsAsFaults = false
+        do {
+            var data: [T] = []
+
+            let result = try NSManagedObject.context.fetch(request).compactMap {
+                $0 as? T
+            }
+            for item in result {
+                data.append(item)
+            }
+            return data
+        } catch {
+            logger.error("Failed to list CoreData objects \(error)")
+        }
+        return []
+    }
+
+    func save() {
+        if let context = managedObjectContext {
+            do {
+                try context.save()
+            } catch let error as NSError {
+                NSManagedObject.logger.error("Failed to save core data context: \(error)")
+            }
+        }
+    }
+
+    class func save() {
+        contextHolder.saveContext()
+    }
+
+    class func delete(object: NSManagedObject?) {
+        if let object: NSManagedObject = object {
+            context.delete(object)
+        }
+    }
+
+    class func deleteWhere(predicate: (NSManagedObject) -> Bool) {
+        list().filter(predicate).forEach {
+            context.delete($0)
+        }
+    }
+
+    class func deleteAll() {
+        let context = NSManagedObject.context
+
+        let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: className)
+        let deleteRequest = NSBatchDeleteRequest(fetchRequest: fetchRequest)
+
+        do {
+            try context.execute(deleteRequest)
+        } catch let error as NSError {
+            logger.error("Failed to delete core data objects \(error)")
+        }
+    }
+}