Add PersistenceManager for loading CoreData container

Shared/PersistenceManager.swift

@@ -0,0 +1,35 @@
+import CoreData
+
+#if os(macOS)
+import AppKit
+#endif
+
+class PersistenceManager {
+    let persistentContainer: NSPersistentContainer = {
+        let container = NSPersistentContainer(name: "LocalStorageModel")
+        container.loadPersistentStores(completionHandler: { (_, error) in
+            if let error = error as NSError? {
+                fatalError("Unresolved error loading persistent store: \(error) - \(error.userInfo)")
+            }
+        })
+        return container
+    }()
+
+    init() {
+        let center = NotificationCenter.default
+
+        #if os(iOS)
+        let notification = UIApplication.willResignActiveNotification
+        #elseif os(macOS)
+        let notification = NSApplication.willResignActiveNotification
+        #endif
+
+        center.addObserver(forName: notification, object: nil, queue: nil) { [weak self] _ in
+            guard let self = self else { return }
+
+            if self.persistentContainer.viewContext.hasChanges {
+                try? self.persistentContainer.viewContext.save()
+            }
+        }
+    }
+}

WriteFreely-MultiPlatform.xcodeproj/project.pbxproj

@@ -38,6 +38,8 @@
 		1756DBB424FECDBB00207AB8 /* PostEditorStatusToolbarView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1756DBB224FECDBB00207AB8 /* PostEditorStatusToolbarView.swift */; };
 		1756DBB724FED3A400207AB8 /* LocalStorageModel.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = 1756DBB524FED3A400207AB8 /* LocalStorageModel.xcdatamodeld */; };
 		1756DBB824FED3A400207AB8 /* LocalStorageModel.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = 1756DBB524FED3A400207AB8 /* LocalStorageModel.xcdatamodeld */; };
+		1756DBBA24FED45500207AB8 /* PersistenceManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1756DBB924FED45500207AB8 /* PersistenceManager.swift */; };
+		1756DBBB24FED45500207AB8 /* PersistenceManager.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1756DBB924FED45500207AB8 /* PersistenceManager.swift */; };
 		1762DCB324EB086C0019C4EB /* CollectionListModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1762DCB224EB086C0019C4EB /* CollectionListModel.swift */; };
 		1762DCB424EB086C0019C4EB /* CollectionListModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1762DCB224EB086C0019C4EB /* CollectionListModel.swift */; };
 		1765F62A24E18EA200C9EBF0 /* SidebarView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1765F62924E18EA200C9EBF0 /* SidebarView.swift */; };
@@ -96,6 +98,7 @@
 		1756AE8024CB844500FD7257 /* View+Keyboard.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "View+Keyboard.swift"; sourceTree = "<group>"; };
 		1756DBB224FECDBB00207AB8 /* PostEditorStatusToolbarView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PostEditorStatusToolbarView.swift; sourceTree = "<group>"; };
 		1756DBB624FED3A400207AB8 /* LocalStorageModel.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = LocalStorageModel.xcdatamodel; sourceTree = "<group>"; };
+		1756DBB924FED45500207AB8 /* PersistenceManager.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PersistenceManager.swift; sourceTree = "<group>"; };
 		1762DCB224EB086C0019C4EB /* CollectionListModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CollectionListModel.swift; sourceTree = "<group>"; };
 		1765F62924E18EA200C9EBF0 /* SidebarView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SidebarView.swift; sourceTree = "<group>"; };
 		17A5388724DDA31F00DEFF9A /* MacAccountView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MacAccountView.swift; sourceTree = "<group>"; };
@@ -237,6 +240,7 @@
 			isa = PBXGroup;
 			children = (
 				17DF328124C87D3300BCE2E3 /* WriteFreely_MultiPlatformApp.swift */,
+				1756DBB924FED45500207AB8 /* PersistenceManager.swift */,
 				17DF328324C87D3500BCE2E3 /* Assets.xcassets */,
 				17DF32D024C8B75C00BCE2E3 /* Account */,
 				1756AE7F24CB841200FD7257 /* Extensions */,
@@ -550,6 +554,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				17DF32AC24C87D3500BCE2E3 /* ContentView.swift in Sources */,
+				1756DBBA24FED45500207AB8 /* PersistenceManager.swift in Sources */,
 				1756AE8124CB844500FD7257 /* View+Keyboard.swift in Sources */,
 				17120DAC24E1B99F002B9F6C /* AccountLoginView.swift in Sources */,
 				17120DA924E1B2F5002B9F6C /* AccountLogoutView.swift in Sources */,
@@ -583,6 +588,7 @@
 				171BFDF824D49FD400888236 /* PostCollection.swift in Sources */,
 				17DF32AD24C87D3500BCE2E3 /* ContentView.swift in Sources */,
 				1765F62B24E18EA200C9EBF0 /* SidebarView.swift in Sources */,
+				1756DBBB24FED45500207AB8 /* PersistenceManager.swift in Sources */,
 				174D313324EC2831006CA9EE /* WriteFreelyModel.swift in Sources */,
 				1756AE7824CB2EDD00FD7257 /* PostEditorView.swift in Sources */,
 				17D435E924E3128F0036B539 /* PreferencesModel.swift in Sources */,