Add LazilyDecoding for CoreData embedded objects

Pachyderm/Model/Attachment.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-public class Attachment: Decodable {
+public class Attachment: Codable {
     public let id: String
     public let kind: Kind
     public let url: URL
@@ -58,7 +58,7 @@ public class Attachment: Decodable {
 }
 
 extension Attachment {
-    public enum Kind: String, Decodable {
+    public enum Kind: String, Codable {
         case image
         case video
         case gifv
@@ -68,7 +68,7 @@ extension Attachment {
 }
 
 extension Attachment {
-    public class Metadata: Decodable {
+    public class Metadata: Codable {
         public let length: String?
         public let duration: Float?
         public let audioEncoding: String?
@@ -99,7 +99,7 @@ extension Attachment {
         }
     }
     
-    public class ImageMetadata: Decodable {
+    public class ImageMetadata: Codable {
         public let width: Int?
         public let height: Int?
         public let size: String?

Pachyderm/Model/Emoji.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-public class Emoji: Decodable {
+public class Emoji: Codable {
     public let shortcode: String
     public let url: URL
     public let staticURL: URL

Pachyderm/Model/Mention.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-public class Mention: Decodable {
+public class Mention: Codable {
     public let url: URL
     public let username: String
     public let acct: String

Tusker.xcodeproj/project.pbxproj

@@ -25,6 +25,7 @@
 		D60D2B8223844C71001B87A3 /* BaseStatusTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60D2B8123844C71001B87A3 /* BaseStatusTableViewCell.swift */; };
 		D60E2F272442372B005F8713 /* StatusMO.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60E2F232442372B005F8713 /* StatusMO.swift */; };
 		D60E2F292442372B005F8713 /* AccountMO.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60E2F252442372B005F8713 /* AccountMO.swift */; };
+		D60E2F2C24423EAD005F8713 /* LazilyDecoding.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60E2F2B24423EAD005F8713 /* LazilyDecoding.swift */; };
 		D60E2F2E244248BF005F8713 /* MastodonCachePersistentStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = D60E2F2D244248BF005F8713 /* MastodonCachePersistentStore.swift */; };
 		D61099B42144B0CC00432DC2 /* Pachyderm.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D61099AB2144B0CC00432DC2 /* Pachyderm.framework */; };
 		D61099BB2144B0CC00432DC2 /* PachydermTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D61099BA2144B0CC00432DC2 /* PachydermTests.swift */; };
@@ -1236,6 +1237,7 @@
 				D6028B9A2150811100F223B9 /* MastodonCache.swift */,
 				D6C693EE216192C2007D6A6D /* TuskerNavigationDelegate.swift */,
 				D6DFC69F242C4CCC00ACC392 /* WeakArray.swift */,
+				D60E2F2B24423EAD005F8713 /* LazilyDecoding.swift */,
 				D6F1F84E2193B9BE00F5FE67 /* Caching */,
 				D6757A7A2157E00100721E32 /* XCallbackURL */,
 				D62D241E217AA46B005076CC /* Shortcuts */,
@@ -1664,6 +1666,7 @@
 				D62D2422217AA7E1005076CC /* UserActivityManager.swift in Sources */,
 				D60D2B8223844C71001B87A3 /* BaseStatusTableViewCell.swift in Sources */,
 				D60E2F272442372B005F8713 /* StatusMO.swift in Sources */,
+				D60E2F2C24423EAD005F8713 /* LazilyDecoding.swift in Sources */,
 				D62D2424217ABF3F005076CC /* NSUserActivity+Extensions.swift in Sources */,
 				D646C958213B367000269FB5 /* LargeImageShrinkAnimationController.swift in Sources */,
 				D6A3BC852321F6C100FD64D5 /* AccountListTableViewController.swift in Sources */,

Tusker/CoreData/AccountMO.swift

@@ -9,6 +9,7 @@
 
 import Foundation
 import CoreData
+import Pachyderm
 
 @objc(AccountMO)
 public class AccountMO: NSManagedObject {
@@ -22,8 +23,8 @@ public class AccountMO: NSManagedObject {
     @NSManaged public var bot: Bool
     @NSManaged public var createdAt: Date?
     @NSManaged public var displayName: String?
-    @NSManaged public var emojis: Data?
+    @NSManaged public var emojisData: Data?
-    @NSManaged public var fields: Data?
+    @NSManaged public var fieldsData: Data?
     @NSManaged public var followersCount: Int64
     @NSManaged public var followingCount: Int64
     @NSManaged public var header: URL?
@@ -36,4 +37,10 @@ public class AccountMO: NSManagedObject {
     @NSManaged public var username: String?
     @NSManaged public var movedTo: AccountMO?
     
+    @LazilyDecoding(arrayFrom: \AccountMO.emojisData)
+    var emojis: [Emoji]
+    
+    @LazilyDecoding(arrayFrom: \AccountMO.fieldsData)
+    var fields: [Account.Field]
+    
 }

Tusker/CoreData/StatusMO.swift

@@ -9,6 +9,7 @@
 
 import Foundation
 import CoreData
+import Pachyderm
 
 @objc(StatusMO)
 public final class StatusMO: NSManagedObject {
@@ -41,4 +42,16 @@ public final class StatusMO: NSManagedObject {
     @NSManaged public var inReplyToAccount: AccountMO?
     @NSManaged public var reblog: StatusMO?
     
+    @LazilyDecoding(arrayFrom: \StatusMO.attachmentsData)
+    var attachments: [Attachment]
+
+    @LazilyDecoding(arrayFrom: \StatusMO.emojisData)
+    var emoji: [Emoji]
+    
+    @LazilyDecoding(arrayFrom: \StatusMO.hashtagsData)
+    var hashtags: [Hashtag]
+    
+    @LazilyDecoding(arrayFrom: \StatusMO.mentionsData)
+    var mentions: [Mention]
+    
 }

Tusker/CoreData/Tusker.xcdatamodeld/Tusker.xcdatamodel/contents

@@ -6,8 +6,8 @@
         <attribute name="bot" optional="YES" attributeType="Boolean" usesScalarValueType="YES"/>
         <attribute name="createdAt" attributeType="Date" usesScalarValueType="NO"/>
         <attribute name="displayName" attributeType="String"/>
-        <attribute name="emojis" attributeType="Binary"/>
+        <attribute name="emojisData" attributeType="Binary"/>
-        <attribute name="fields" optional="YES" attributeType="Binary"/>
+        <attribute name="fieldsData" optional="YES" attributeType="Binary"/>
         <attribute name="followersCount" attributeType="Integer 64" defaultValueString="0" usesScalarValueType="YES"/>
         <attribute name="followingCount" attributeType="Integer 64" defaultValueString="0" usesScalarValueType="YES"/>
         <attribute name="header" attributeType="URI"/>

Tusker/LazilyDecoding.swift

@@ -0,0 +1,63 @@
+//
+//  LazyDecoding.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 4/11/20.
+//  Copyright © 2020 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+
+private let decoder = PropertyListDecoder()
+private let encoder = PropertyListEncoder()
+
+@propertyWrapper
+struct LazilyDecoding<Enclosing, Value: Codable> {
+
+    private let keyPath: ReferenceWritableKeyPath<Enclosing, Data?>
+    private let fallback: Value
+    private var value: Value?
+    
+    init(from keyPath: ReferenceWritableKeyPath<Enclosing, Data?>, fallback: Value) {
+        self.keyPath = keyPath
+        self.fallback = fallback
+    }
+
+    var wrappedValue: Value {
+        get { fatalError("called LazilyDecoding wrappedValue getter") }
+        set { fatalError("called LazilyDecoding wrappedValue setter") }
+    }
+    
+    static subscript(_enclosingInstance instance: Enclosing, wrapped wrappedKeyPath: ReferenceWritableKeyPath<Enclosing, Value>, storage storageKeyPath: ReferenceWritableKeyPath<Enclosing, Self>) -> Value {
+        get {
+            var wrapper = instance[keyPath: storageKeyPath]
+            if let value = wrapper.value {
+                return value
+            } else {
+                guard let data = instance[keyPath: wrapper.keyPath] else { return wrapper.fallback }
+                do {
+                    let value = try decoder.decode(Value.self, from: data)
+                    wrapper.value = value
+                    instance[keyPath: storageKeyPath] = wrapper
+                    return value
+                } catch {
+                    return wrapper.fallback
+                }
+            }
+        }
+        set {
+            var wrapper = instance[keyPath: storageKeyPath]
+            wrapper.value = newValue
+            instance[keyPath: storageKeyPath] = wrapper
+            let newData = try? encoder.encode(newValue)
+            instance[keyPath: wrapper.keyPath] = newData
+        }
+    }
+    
+}
+
+extension LazilyDecoding {
+    init(arrayFrom keyPath: ReferenceWritableKeyPath<Enclosing, Data?>) {
+        self.init(from: keyPath, fallback: [] as! Value)
+    }
+}