From 00e8b7c80e3388b23dcaf400a70ab79eeb7e7197 Mon Sep 17 00:00:00 2001
From: Riley Testut <riley@rileytestut.com>
Date: Mon, 5 Oct 2020 14:23:19 -0700
Subject: [PATCH] Adds @Managed property wrapper
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

• Keeps strong reference to wrapped managed object’s context.
• Projected value simplifies accessing properties on context’s thread.
---
 AltStore.xcodeproj/project.pbxproj |  4 +++
 AltStore/Types/Managed.swift       | 49 ++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 AltStore/Types/Managed.swift

diff --git a/AltStore.xcodeproj/project.pbxproj b/AltStore.xcodeproj/project.pbxproj
index bae69928..ef1e33bc 100644
--- a/AltStore.xcodeproj/project.pbxproj
+++ b/AltStore.xcodeproj/project.pbxproj
@@ -226,6 +226,7 @@
 		BFAECC5F2501B0BF00528F27 /* ALTConstants.h in Headers */ = {isa = PBXBuildFile; fileRef = BFD52BD222A06EFB000B7ED1 /* ALTConstants.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		BFAECC602501B0BF00528F27 /* NSError+ALTServerError.h in Headers */ = {isa = PBXBuildFile; fileRef = BF1E314822A060F400370A3C /* NSError+ALTServerError.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		BFB3645A2325985F00CD0EB1 /* FindServerOperation.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFB364592325985F00CD0EB1 /* FindServerOperation.swift */; };
+		BFB39B5C252BC10E00D1BE50 /* Managed.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFB39B5B252BC10E00D1BE50 /* Managed.swift */; };
 		BFB4323F22DE852000B7F8BC /* UpdateCollectionViewCell.xib in Resources */ = {isa = PBXBuildFile; fileRef = BFB4323E22DE852000B7F8BC /* UpdateCollectionViewCell.xib */; };
 		BFB49AAA23834CF900D542D9 /* ALTAnisetteData.m in Sources */ = {isa = PBXBuildFile; fileRef = BFB49AA823834CF900D542D9 /* ALTAnisetteData.m */; };
 		BFB6B21E231870160022A802 /* NewsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = BFB6B21D231870160022A802 /* NewsViewController.swift */; };
@@ -655,6 +656,7 @@
 		BFA8172A23C5633D001B5953 /* FetchAnisetteDataOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FetchAnisetteDataOperation.swift; sourceTree = "<group>"; };
 		BFB1169C22932DB100BB457C /* apps.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; path = apps.json; sourceTree = "<group>"; };
 		BFB364592325985F00CD0EB1 /* FindServerOperation.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FindServerOperation.swift; sourceTree = "<group>"; };
+		BFB39B5B252BC10E00D1BE50 /* Managed.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Managed.swift; sourceTree = "<group>"; };
 		BFB4323E22DE852000B7F8BC /* UpdateCollectionViewCell.xib */ = {isa = PBXFileReference; lastKnownFileType = file.xib; path = UpdateCollectionViewCell.xib; sourceTree = "<group>"; };
 		BFB49AA823834CF900D542D9 /* ALTAnisetteData.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = ALTAnisetteData.m; path = "Dependencies/AltSign/AltSign/Model/Apple API/ALTAnisetteData.m"; sourceTree = SOURCE_ROOT; };
 		BFB49AA923834CF900D542D9 /* ALTAnisetteData.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = ALTAnisetteData.h; path = "Dependencies/AltSign/AltSign/Model/Apple API/ALTAnisetteData.h"; sourceTree = SOURCE_ROOT; };
@@ -901,6 +903,7 @@
 			isa = PBXGroup;
 			children = (
 				BF41B807233433C100C593A3 /* LoadingState.swift */,
+				BFB39B5B252BC10E00D1BE50 /* Managed.swift */,
 			);
 			path = Types;
 			sourceTree = "<group>";
@@ -2387,6 +2390,7 @@
 				BFF0B69A2322D7D0007A79E1 /* UIScreen+CompactHeight.swift in Sources */,
 				BF8F69C222E659F700049BA1 /* AppContentViewController.swift in Sources */,
 				BF08858522DE7EC800DE9F1E /* UpdateCollectionViewCell.swift in Sources */,
+				BFB39B5C252BC10E00D1BE50 /* Managed.swift in Sources */,
 				BF770E5822BC3D0F002A40FE /* RefreshGroup.swift in Sources */,
 				BF18B0F122E25DF9005C4CF5 /* ToastView.swift in Sources */,
 				BF3D649F22E7B24C00E9056B /* CollapsingTextView.swift in Sources */,
diff --git a/AltStore/Types/Managed.swift b/AltStore/Types/Managed.swift
new file mode 100644
index 00000000..1bce7bb4
--- /dev/null
+++ b/AltStore/Types/Managed.swift
@@ -0,0 +1,49 @@
+//
+//  Managed.swift
+//  AltStore
+//
+//  Created by Riley Testut on 10/5/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import CoreData
+
+@propertyWrapper @dynamicMemberLookup
+struct Managed<ManagedObject: NSManagedObject>
+{
+    var wrappedValue: ManagedObject {
+        didSet {
+            self.managedObjectContext = self.wrappedValue.managedObjectContext
+        }
+    }
+    private var managedObjectContext: NSManagedObjectContext?
+    
+    var projectedValue: Managed<ManagedObject> {
+        return self
+    }
+    
+    init(wrappedValue: ManagedObject)
+    {
+        self.wrappedValue = wrappedValue
+        self.managedObjectContext = wrappedValue.managedObjectContext
+    }
+    
+    subscript<T>(dynamicMember keyPath: KeyPath<ManagedObject, T>) -> T
+    {
+        var result: T!
+        
+        if let context = self.managedObjectContext
+        {
+            context.performAndWait {
+                result = self.wrappedValue[keyPath: keyPath]
+            }
+        }
+        else
+        {
+            result = self.wrappedValue[keyPath: keyPath]
+        }
+        
+        return result
+    }
+}