Adds initial support for 3rd party Sources

AltStore/Extensions/JSONDecoder+ManagedObjectContext.swift

@@ -1,36 +0,0 @@
-//
-//  JSONDecoder+ManagedObjectContext.swift
-//  Harmony
-//
-//  Created by Riley Testut on 10/3/18.
-//  Copyright © 2018 Riley Testut. All rights reserved.
-//
-
-import Foundation
-import CoreData
-
-private extension CodingUserInfoKey
-{
-    static let managedObjectContext = CodingUserInfoKey(rawValue: "managedObjectContext")!
-}
-
-public extension JSONDecoder
-{
-    var managedObjectContext: NSManagedObjectContext? {
-        get {
-            let managedObjectContext = self.userInfo[.managedObjectContext] as? NSManagedObjectContext
-            return managedObjectContext
-        }
-        set {
-            self.userInfo[.managedObjectContext] = newValue
-        }
-    }
-}
-
-public extension Decoder
-{
-    var managedObjectContext: NSManagedObjectContext? {
-        let managedObjectContext = self.userInfo[.managedObjectContext] as? NSManagedObjectContext
-        return managedObjectContext
-    }
-}

AltStore/Extensions/JSONDecoder+Properties.swift

@@ -0,0 +1,64 @@
+//
+//  JSONDecoder+Properties.swift
+//  Harmony
+//
+//  Created by Riley Testut on 10/3/18.
+//  Copyright © 2018 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import CoreData
+
+extension CodingUserInfoKey
+{
+    static let managedObjectContext = CodingUserInfoKey(rawValue: "managedObjectContext")!
+    static let sourceURL = CodingUserInfoKey(rawValue: "sourceURL")!
+}
+
+public final class JSONDecoder: Foundation.JSONDecoder
+{
+    @DecoderItem(key: .managedObjectContext)
+    var managedObjectContext: NSManagedObjectContext?
+    
+    @DecoderItem(key: .sourceURL)
+    var sourceURL: URL?
+}
+
+extension Decoder
+{
+    var managedObjectContext: NSManagedObjectContext? { self.userInfo[.managedObjectContext] as? NSManagedObjectContext }
+    var sourceURL: URL? { self.userInfo[.sourceURL] as? URL }
+}
+
+@propertyWrapper
+struct DecoderItem<Value>
+{
+    let key: CodingUserInfoKey
+    
+    var wrappedValue: Value? {
+        get { fatalError("only works on instance properties of classes") }
+        set { fatalError("only works on instance properties of classes") }
+    }
+    
+    init(key: CodingUserInfoKey)
+    {
+        self.key = key
+    }
+    
+    public static subscript<OuterSelf: JSONDecoder>(
+        _enclosingInstance decoder: OuterSelf,
+        wrapped wrappedKeyPath: ReferenceWritableKeyPath<OuterSelf, Value?>,
+        storage storageKeyPath: ReferenceWritableKeyPath<OuterSelf, Self>
+    ) -> Value? {
+        get {
+            let wrapper = decoder[keyPath: storageKeyPath]
+
+            let value = decoder.userInfo[wrapper.key] as? Value
+            return value
+        }
+        set {
+            let wrapper = decoder[keyPath: storageKeyPath]
+            decoder.userInfo[wrapper.key] = newValue
+        }
+    }
+}

AltStore/Extensions/NSError+LocalizedFailure.swift

@@ -15,4 +15,13 @@ extension NSError
         let localizedFailure = (self.userInfo[NSLocalizedFailureErrorKey] as? String) ?? (NSError.userInfoValueProvider(forDomain: self.domain)?(self, NSLocalizedFailureErrorKey) as? String)
         return localizedFailure
     }
+    
+    func withLocalizedFailure(_ failure: String) -> NSError
+    {
+        var userInfo = self.userInfo
+        userInfo[NSLocalizedFailureErrorKey] = failure
+        
+        let error = NSError(domain: self.domain, code: self.code, userInfo: userInfo)
+        return error
+    }
 }