added helpers for decodeContext

Signed-off-by: Matt Bruce <matt.bruce@verizon.com>

MVMCore/MVMCore/Models/Extensions/Decoder+UserInfo.swift

@@ -111,3 +111,24 @@ extension JSONDecoder {
         get { return userInfo[.contextKey] as? DecodingContext }
      }
 }
+
+extension KeyedDecodingContainer {
+    public func decodeContext<T>(_ type: T.Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> T where T : Decodable {
+        guard let value = try? decodeContextIfPresent(type, forKey: key) else {
+            throw DecodingError.keyNotFound(key, .init(codingPath: [key], debugDescription: "Key Not Found"))
+        }
+        return value
+    }
+    
+    public func decodeContextIfPresent<T>(_ type: T.Type, forKey key: KeyedDecodingContainer<K>.Key) throws -> T? where T : Decodable {
+        if let value = try self.decodeIfPresent(T.self, forKey: key) {
+            return value
+            
+        } else if let decoder = try? superDecoder(forKey: key), let value = decoder.context?.value(forKey: key.stringValue) as? T {
+            return value
+            
+        } else {
+            return nil
+        }
+    }
+}

MVMCore/MVMCore/Models/Model/ModelProtocol.swift

@@ -35,7 +35,7 @@ public protocol ModelProtocol: Codable {
 extension ModelProtocol {
     
     static public func decode<K: CodingKey>(keyedContainer: KeyedDecodingContainer<K>, codingKey: K) throws -> Self? {
-        try keyedContainer.decodeIfPresent(self, forKey: codingKey)
+        try keyedContainer.decodeContextIfPresent(self, forKey: codingKey)
     }
     
     static public func decode(unkeyedContainer: inout UnkeyedDecodingContainer) throws -> Self? {