From b2eb88f7f69a3c4242343ff4dc0de8df557f7ae6 Mon Sep 17 00:00:00 2001
From: panxi <xinleiryan.pan@verizonwireless.com>
Date: Sun, 24 Nov 2019 23:14:25 -0500
Subject: [PATCH] update array decoding method

---
 MVMCore/MVMCore/Models/Model/Model.swift      | 14 +++++
 .../MVMCore/Models/Model/ModelRegistry.swift  | 59 +++++++++++--------
 2 files changed, 47 insertions(+), 26 deletions(-)

diff --git a/MVMCore/MVMCore/Models/Model/Model.swift b/MVMCore/MVMCore/Models/Model/Model.swift
index 44e1025..8e37837 100644
--- a/MVMCore/MVMCore/Models/Model/Model.swift
+++ b/MVMCore/MVMCore/Models/Model/Model.swift
@@ -12,5 +12,19 @@ public protocol Model: Codable {
 
     static var identifier: String { get }
     
+    static func mvmdecode<K:CodingKey>(keyedContainer: KeyedDecodingContainer<K>, codingKey: K) throws -> Self?
+    static func mvmdecode(unkeyedContainer: inout UnkeyedDecodingContainer) throws -> Self?
+}
+
+extension Model {
+    static public func mvmdecode<K:CodingKey>(keyedContainer: KeyedDecodingContainer<K>, codingKey: K) throws -> Self? {
+        let m = try keyedContainer.decodeIfPresent(self, forKey: codingKey)
+        return m
+    }
+    
+    static public func mvmdecode(unkeyedContainer: inout UnkeyedDecodingContainer) throws -> Self? {
+        let m = try unkeyedContainer.decodeIfPresent(self)
+        return m
+    }
 }
 
diff --git a/MVMCore/MVMCore/Models/Model/ModelRegistry.swift b/MVMCore/MVMCore/Models/Model/ModelRegistry.swift
index cd40a83..0b83a6f 100644
--- a/MVMCore/MVMCore/Models/Model/ModelRegistry.swift
+++ b/MVMCore/MVMCore/Models/Model/ModelRegistry.swift
@@ -24,28 +24,6 @@ public struct ModelRegistry {
     }
 }
 
-extension UnkeyedDecodingContainer {
-    
-    public mutating func decodeUnKeyedIfPresent<T, C:CodingKey>(_ type: T.Type, typeCodingKey: C) throws -> T? where T : Decodable {
-        let meta = try self.nestedContainer(keyedBy: C.self)
-        guard let type = try meta.decodeIfPresent(String.self, forKey: typeCodingKey) else {
-            return nil
-        }
-
-        //get the type
-        guard let found = ModelRegistry.types[type] else {
-            throw ModelRegistry.Error.decoderErrorModelNotMapped
-        }
-        let model = try self.decode(found)
-        
-        guard let m = model as? T else {
-            throw ModelRegistry.Error.decoderError
-        }
-        return m
-    }
-    
-}
-
 extension KeyedDecodingContainer where Key: CodingKey {
     
     private enum TypeCodingKey: String, CodingKey {
@@ -79,17 +57,46 @@ extension KeyedDecodingContainer where Key: CodingKey {
             throw ModelRegistry.Error.decoderErrorModelNotMapped
         }
         
-        //get the decoder for the propertyKey
-        let decoder = try self.superDecoder(forKey: codingKey)
-        
         //decode the type using the decoder
-        let model = try found.init(from: decoder)
+        let model = try found.mvmdecode(keyedContainer: self, codingKey: codingKey)
 
         guard let m = model as? T else {
             throw ModelRegistry.Error.decoderError
         }
+        
         return m
     }
+    
+    
+    public func decodeArrayIfPresent<C:CodingKey>(codingKey: KeyedDecodingContainer<K>.Key, typeCodingKey: C) throws -> [Model]? {
+        
+        var unkeyedContainer = try nestedUnkeyedContainer(forKey: codingKey)
+        var otherUnkeyedContainer = try nestedUnkeyedContainer(forKey: codingKey)
+        var attributes = [Model.Type]()
+        while !unkeyedContainer.isAtEnd {
+
+            let meta = try unkeyedContainer.nestedContainer(keyedBy: C.self)
+            guard let type = try meta.decodeIfPresent(String.self, forKey: typeCodingKey) else {
+                return nil
+            }
+            //get the type
+            guard let found = ModelRegistry.types[type] else {
+                throw ModelRegistry.Error.decoderErrorModelNotMapped
+            }
+            attributes.append(found)
+        }
+        
+        var i = 0
+        var models = [Model]()
+        while !otherUnkeyedContainer.isAtEnd {
+            let foundModel = attributes[i]
+            if let model = try foundModel.mvmdecode(unkeyedContainer: &otherUnkeyedContainer) {
+                models.append(model)
+            }
+            i += 1
+        }
+        return models.count > 0 ? models : nil
+    }
 }